TEMPERATURE MICROSTRUCTURE IN HOWE SOUND by LAURENT ERNEST BILODEAU B. A. Sc. L a v a l U n i v e r s i t y , 1972 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES i n the Department o f P h y s i c s and the I n s t i t u t e o f Oceanography We accept t h i s t h e s i s as conforming to the required THE standard UNIVERSITY OF BRITISH COLUMBIA SEPTEMBER 1978 Laurent Ernest Bilodeau, 1978 In presenting an advanced the I Library further for this degree shall agree scholarly by his of this written at make that for freely It British 12 QMtA of Columbia, British by for gain Columbia shall that not the requirements reference copying t h e Head is understood of of of for extensive permission. University fulfilment available may b e g r a n t e d financial 2075 Wesbrook P l a c e Vancouver, Canada V6T 1WS Date it permission purposes thesis in p a r t i a l the U n i v e r s i t y representatives. Department The thesis of I agree and this be a l l o w e d or that study. thesis o f my D e p a r t m e n t copying for or publication without my Abstract Temperature m i c r o s t r u c t u r e o b s e r v a t i o n s Sound a r e p r e s e n t e d i n Howe and r e l a t e d t o t h e i r o c e a n o g r a p h i c c o n t e x t , some i n s t a n c e s , two f r e e - f a l l i n g taneously obtained with separations to l o o k a t t h e l a t e r a l probes have been l a u n c h e d o f 10 t o 20 m a t t h e s u r f a c e extent In simul- i n an attempt of temperature m i c r o s t r u c t u r e features. P a t c h e s o f temperature g r a d i e n t v a r i a n c e were found where t h e gradient presented peak v a l u e s of both signs a t smaller scales. These p a t c h e s w e r e u s u a l l y o b s e r v e d b y o n e p r o b e o n l y a n d seem t o e x t e n d e r a l l y o v e r l e s s t h a n 20 m. took mostly detected icantly by both probes, i n d i c a t i n g l a r g e r t h a n 20 m. their instances t h e same s i g n w i t h i n a g i v e n p a t c h . also discussed for I n other t h e peak g r a d i e n t an e x p l a n a t i o n existence. Basin, t h e Deep W a t e r o c c a s i o n a l l y r e c e i v e s l a r g e i n f l u x e s o f water from t h e S t r a i t o f Georgia. stays e s s e n t i a l l y trapped homogeneous w i t h t i m e . behind a 75 m d e e p s i l l A model i s p r e s e n t e d the molecular which r e l a t e s the rate a t c o e f f i c i e n t of heat d i f f u s i o n . water column a r e d i s c u s s e d of v e r t i c a l heat transport. Otherwise, a n d b e c o m e s more w h i c h t e m p e r a t u r e becomes h o m o g e n e o u s t o t e m p e r a t u r e g r a d i e n t and i s signif- of temperature m i c r o s t r u c t u r e a r e i n terms o f mechanisms t h a t c o u l d p r o v i d e I n Howe S o u n d ' s I n n e r it values Such p a t c h e s were u s u a l l y that t h e i r h o r i z o n t a l extent These types lat- variance Other p a r t s of the i n terms o f t h e Osborn-Cox (1972) model i i i Table of contents Page Abstract Table of contents i i i i i List of tables List of figures v i i Acknowledgments x i Chapter I : v i Introduction 1 1.1 General 1 1.2 Howe Sound: g e o g r a p h y , t i d e s , introduction and r i v e r 1.3 Earlier winds discharge 2 investigation of the p h y s i c a l o c e a n o g r a p h y o f Howe S o u n d Chapter I I : 4 New a s p e c t s o f t h e o c e a n o g r a p h i c and c u r r e n t m e t e r d a t a 10 II. 1 The I n t e r m e d i a t e Water II.2 T h e Deep W a t e r r e n e w a l i n t h e F a l l o f 1 9 7 3 C h a p t e r I I I : M i c r o s t r u c t u r e methods . 10 . . 13 and d a t a p r o c e s s i n g . . 17 III.l Probes and r e s o l u t i o n 17 III. 2 Method o f d a t a p r o c e s s i n g 19 III. 3 Summary o f t h e d a t a 21 iv Page Chapter IV: Temperature s t r u c t u r e of Howe Sound i n November 1 9 7 3 and February 1974 . . . . 24 IV.1 Temperature s t r u c t u r e i n November 1 9 7 3 . . . 24 IV.2 Temperature s t r u c t u r e i n February 1974 . . . 27 a) Recent e v o l u t i o n o f water p r o p e r t i e s i n Howe Sound 27 b) Temperature s t r u c t u r e i n t h e Outer B a s i n . c) Temperature s t r u c t u r e i n the Inner B a s i n ' s . I n t e r m e d i a t e Water d) 30 Temperature s t r u c t u r e i n the Inner B a s i n ' s Deep Water IV. 3 28 32 Discussion a) An I n t e r m e d i a t e Water c i r c u l a t i o n p a t t e r n ? . b) The Osborn-Cox model c) A model f o r an i s o l a t e d . 35 and inhomogeneous volume o f f l u i d Chapter V: 34 D e t a i l e d a s p e c t o f temperature 41 microstructure . 44 V. l Introduction 44 V.2 Detailed profiles 45 a) November 1 9 7 3 p r o f i l e s 45 b) Outer B a s i n , February 1974 c) Inner B a s i n I n t e r m e d i a t e Water (February 1 9 7 4 ) 50 d) Inner B a s i n Deep Water (February 1 9 7 4 ) 57 . . . . 47 Page V.3 Discussion a) Summary o f m i c r o s t r u c t u r e d e s c r i p t i o n b) R e l a t i o n s h i p between temperature 59 and temperature gradient m i c r o s t r u c t u r e of microstructure . . . . . . . 60 c) L a t e r a l extent 62 d) Turbulent or not? 64 e) D o u b l y - d i f f u s i v e or not? 67 Chapter V I : Conclusion 70 References 72 Tables 75 Figures 78 List List of Tables of the locations and times a t which double d r o p s w e r e made d u r i n g t h e F e b r u a r y 1974 m i c r o structure of cruise, together with t h e probes a t l a u n c h and r e c o v e r y . List of the locations and times a t which d r o p s w e r e made d u r i n g structure for the separation cruise, single t h e November 1 9 7 3 m i c r o - together with t h e mean s q u a r e v e r t i c a l the values observed temperature Mean s q u a r e v a l u e s o f t h e v e r t i c a l gradient. temperature g r a d i e n t and n e t t e m p e r a t u r e change o b s e r v e d a c r o s s t h e I n t e r m e d i a t e Water d u r i n g t h e F e b r u a r y 1974 m i c r o s t r u c t u r e cruise. vii List of Figures Fig. 1 Chart o f Howe S o u n d . Fig. 2 L o n g i t u d i n a l s e c t i o n o f Howe Sound a n d c r o s s s e c t i o n s made a t t h e s i l l Fig. 3 a n d a t s t a t i o n Howe 4. T y p i c a l w i n t e r p r o f i l e s o f t e m p e r a t u r e and s a l i n i t y Outer B a s i n and i n t h e Inner Fig. 4 channel i n the B a s i n o f Howe S o u n d . Time s e r i e s o f t e m p e r a t u r e o b s e r v a t i o n s obtained i n the O u t e r B a s i n a t d e p t h s o f 100 m a n d more. Fig. 5 Time s e r i e s o f t e m p e r a t u r e a n d s a l i n i t y observations o b t a i n e d b e t w e e n 20 a n d 75 m i n b o t h b a s i n s o f Howe S o u n d . Fig. 6 Time s e r i e s o f o b s e r v a t i o n s o f (a) temperature, (b) s a l i n i t y , ( c ) s i g m a - t a n d ( d ) d i s s o l v e d o x y g e n a t d e p t h s o f 100 m and Fig. 7 more a t s t a t i o n Howe 4 ( I n n e r B a s i n ) . L o n g i t u d i n a l s e c t i o n o f Howe Sound s h o w i n g t h e l o c a t i o n o f the I n t e r m e d i a t e Fig. 8 W a t e r a n d o f t h e Deep W a t e r . D i s t r i b u t i o n of temperature, oxygen along salinity the center of t h e Inner and d i s s o l v e d B a s i n on September 20, 1973. Fig. 9 D i s t r i b u t i o n o f T, S a n d D.0. a l o n g Inner F i g . 10 11 13, 1973. D i s t r i b u t i o n o f T, S a n d D.0. a l o n g Inner Fig. B a s i n o n November B a s i n on January the center of the the center ofthe 22, 1974. T i m e s e r i e s o f t e m p e r a t u r e a n d N-S c u r r e n t obtained velocity a t s t a t i o n Howe 4 a t a d e p t h o f 150 m b y a n A a n d e r a a c u r r e n t m e t e r b e t w e e n O c t o b e r 3 a n d November 15, 1973. viii Fig. 12 Description of Fig. 13 o f a "Pumpkin" m i c r o s t r u c t u r e i t stemperature sensing Location p r o f i l e r and element. of the microstructure p r o f i l e s obtained i n Howe Sound i n November 1 9 7 3 . Fig. 14 Overall profile o f Drop P-10. Fig. 15 Overall profile o f Drop P - l l . Fig. 16 Overall profile o f Drop P-12. Fig. 17 Overall profile o f Drop P-13. Fig. 18 Overall profile o f D r o p P-14. Fig. 19 Overall profile o f Drop P-15. Fig. 20 Overall profile o f D r o p P-16. Fig. 21 Detailed segment f r o m Drop P-12. Fig. 22 Detailed segment f r o m Drop P-12. Fig. 23 Detailed segment f r o m D r o p P - 1 3 . Fig. 24 Detailed segment f r o m Drop P-13. Fig. 25 STD l o n g c h a n n e l s e c t i o n made o n November 2 2 , 1 9 7 4 in Fig. 26 the Inner Basin STD c r o s s o f Howe S o u n d . c h a n n e l s e c t i o n made o n November 2 2 , 1 9 7 4 a t s t a t i o n Howe 4. Fig. 27 STD c r o s s c h a n n e l s e c t i o n made o n November 2 2 , 1 9 7 4 a t s t a t i o n Howe 4.7. Fig. 28 Location of themicrostructure Howe Sound i n F e b r u a r y 1 9 7 4 . Fig. 29 Overall profile o f D r o p 6. Fig. 30 Overall profile o f D r o p 7. Fig. 31 Overall profile o f D r o p 8. p r o f i l e s obtained i n ix Fig. 32 O v e r a l l p r o f i l e o f Drop 9. Fig. 33 O v e r a l l p r o f i l e o f Drop 1 0 . Fig. 34 Deep p a r t of Drop 7 w i t h an expanded temperature scale. Fig. 35 Deep p a r t o f Drop 8 w i t h an expanded temperature scale. Fig. 36 Deep p a r t o f Drop 9 w i t h an expanded temperature s c a l e . Fig. 37 Deep p a r t of Drop 10 w i t h an expanded temperature Fig. 38 Comparison between STD p r o f i l e s scale. made on January 22 and February 4, 1 9 7 4 , i n both Howe Sound's b a s i n s . Fig. 39 STD l o n g channel s e c t i o n made on February 6, 1 9 7 4 i n Howe Sound's Inner B a s i n . Fig. 40 STD c r o s s channel s e c t i o n made a t s t a t i o n Howe 4 on February 6, 1 9 7 4 . Fig. 41 Detailed p r o f i l e from Drop 6. Fig. 42 Detailed p r o f i l e from Drop 6. Fig. 43 Detailed p r o f i l e from Drop 6. Fig. 44 Detailed p r o f i l e from Drop 7. Fig. 45 Detailed p r o f i l e from Drop 7. Fig. 46 Detailed p r o f i l e from Drop 7. Fig. 47 Detailed p r o f i l e from Drop 8. Fig. 48 Detailed p r o f i l e from Drop 8. Fig. 49 Detailed p r o f i l e from Drop 9. Fig. 50 Detailed p r o f i l e from Drop 9. Fig. 51 Detailed p r o f i l e from Drop 9. Fig. 52 Detailed p r o f i l e from Drop 10. Fig. 53 Detailed p r o f i l e from Drop 10. X Fig. 54 Detailed p r o f i l e f r o m Drop 1 0 . Fig. 55 Detailed p r o f i l e f r o m t h e Deep W a t e r o f D r o p 7. Fig. 56 Detailed p r o f i l e f r o m t h e Deep W a t e r o f D r o p 7. Fig. 57 Detailed p r o f i l e f r o m t h e Deep W a t e r o f D r o p 8. Acknowledgments I am s u p p o r t and to the like Dr G. L. this thesis. occasional t o t h a n k Dr c r i t i c i s m of i n d e b t e d t o Dr Thomas O s b o r n f o r advice through a l l phases of the completion of p a t i e n c e and also greatly the Pickard and comments a b o u t t h e experience, lead f i n a n c i a l help, i t were a l l i n v a l u a b l e . I would P a u l L e b l o n d f o r h i s d e t a i l e d and positive early lack of His work w h i c h his and Dr early R. final W. d r a f t s of Burling draft. this thesis, for very and appropriate 1 Chapter I Introduction 1.1 General Introduction. The p u r p o s e s t r u c t u r e and f i n e of t h i s t h e s i s i s to present temperature micro- s t r u c t u r e o b s e r v a t i o n s w h i c h w e r e o b t a i n e d i n Howe Sound i n November 1973 a n d F e b r u a r y 1 9 7 4 , a n d t o i n v e s t i g a t e some o f their significance. The t e r m " m i c r o s t r u c t u r e " a p p l i e s t o t h e d i s t r i b u t i o n o f oceanographic p r o p e r t i e s a t s c a l e s s m a l l e r t h a n one m e t r e . Observa- t i o n s r e p o r t e d b y Gregg e t a l . (1973) i n an o c e a n i c environment t h a t most o f t h e v a r i a n c e o f t h e temperature s c a l e s s m a l l e r t h a n 0.1 m. of the temperature s c a l e s o f i m. g r a d i e n t i s found a t I n the d i s t r i b u t i o n of s p e c t r a l densities g r a d i e n t , G r e g g e t a l . f o u n d a s p e c t r a l minimum G a r g e t t (1976) u s e d as a p p l y i n g t o s c a l e s l a r g e r this to define "fine than a metre, Gargett's d e f i n i t i o n i s retained f o r this "microstructure" w i l l Little show apply here i s known a b o u t near structure" up t o t e n s o f m e t r e s . t h e s i s and, consequently, t o s c a l e s s m a l l e r t h a n one m e t r e . t h e o c c u r r e n c e and t h e r o l e o f temper- a t u r e m i c r o s t r u c t u r e i n f j o r d s and i n l e t s . Drinkwater (1973) used temperature m i c r o s t r u c t u r e o b s e r v a t i o n s i n a study of the r o l e of t i d a l mixing i n Rupert and H o l b e r g I n l e t s to detect the occurrence of 2 turbulent stirring. He f o u n d t h a t t u r b u l e n t s t i r r i n g association with t i d a l winds. less occurred i n currents and, near the surface, w i t h He t r a c e d a m i d - d e p t h intrusion into Holberg Inlet surface and observed t e m p e r a t u r e m i c r o s t r u c t u r e away f r o m t h e m o u t h o f t h e i n l e t . other published study d e s c r i b e d o r used temperature No microstructure observations obtained i n i n l e t s . Howe S o u n d was c h o s e n f o r t h i s a c c e s s and because study because i t i s easy o f i t has been t h e f o c u s o f s e v e r a l i n v e s t i g a t i o n s h a v e p r o v i d e d much b a c k g r o u n d i n f o r m a t i o n about i t s oceanography which f o r the p e r i o d o f 1971 t o 1974. 1.2 Howe Sound: g e o g r a p h y , t i d e s , wind, r i v e r discharge. Howe Sound i s a f j o r d Vancouver, It inlet located 30 km N o r t h W e s t o f on t h e m a i n l a n d c o a s t o f t h e S t r a i t of Georgia (seefig. 1). c o n s i s t s o f two b a s i n s s e p a r a t e d b y a s i l l w i t h a maximum d e p t h o f 70 m ( s e e f i g . 1 ) . The O u t e r B a s i n ( a l s o c a l l e d a number o f i s l a n d s a n d p a s s a g e s . C h a r l o t t e Channel, i s about South Basin) The s o u t h e r n m o s t passage, features t h e Queen 250 m deep a l o n g i t s e n t i r e l e n g t h . The I n n e r B a s i n ( a l s o c a l l e d N o r t h B a s i n ) h a s a maximum d e p t h o f 290 m and a mean w i d t h o f a b o u t 3 km. The s i l l i s l o c a t e d 28 km f r o m t h e m o u t h o f Howe S o u n d a n d 17 km f r o m t h e h e a d . of the s i l l i s presented i n fig. 2. A cross channel profile 3 Point Atkinson Sound. i s the closest At Point Atkinson, tidal the amplitude r e f e r e n c e p o i n t t o Howe r a t i o o f the four main consti- tuents i s : .l M + K °1 S + 2 _ 2.810 2.979 2 + + 1.555 0.748 _ . Defant (1961, p.307) d e s c r i b e s s u c h a v a l u e o f t h e r a t i o as a m i x e d , mainly semi-diurnal type. Sound) i s s m a l l e r t h a n The t i d a l r a n g e a t S q u a m i s h ( h e a d o f Howe that of Point Atkinson a few c e n t i m e t r e s w h i l e t h e phases l a g b e h i n d by a few minutes Point Atkinson The graphic (Canadian tidal mean t i d a l S e r v i c e , 1977). the s i l l those of Point S e r v i c e , 1977). For the purpose of a simple i s a b o u t 45 m. tidal I f t h e f l o w were Hydro- prism which suggests smaller but not negligible that baroclinic Buckley tides model, uniform a n d i f t h e t i d e was p u r e l y s e m i - d i u r n a l , t h e mean reports a calculation tidal (1977) have a effect. Atmospheric Environment S e r v i c e operates which i s located i n the center of the v a l l e y , t h e s i t e o f FMC o f C a n a d a L t d . records Thus t h e r a n g e a t S q u a m i s h i s 3.1 m ( C a n a d i a n r a n g e w o u l d g i v e r i s e t o p e a k v e l o c i t i e s o f 8.5cm/sec. The Atkinson p r e d i c t i o n s c a n b e u s e d a c c u r a t e l y i n Howe S o u n d . t h e mean d e p t h o f t h e s i l l over Hydrographic ( m o u t h o f Howe S o u n d ) b y a n anemometer c l o s e t o t h e w a t e r , on ( f i g . 1 ) , near Squamish. t h e h o u r l y wind r u n and d i r e c t i o n steep mountains which l i n e the v a l l e y , i n octants. The anemometer Because o f t h e t h e wind blows o n l y seldom the E a s t o f t h e West. Down-inlet winds dominate d u r i n g w i n t e r to March) and u p - i n l e t winds dominate d u r i n g from (October t h e summer ( A p r i l t o August). that A more d e t a i l e d study of the hourly wind records reveals t h e r e a r e p e r i o d s when t h e d i u r n a l w i n d c y c l e a c c o u n t s f o r m o s t of t h e v a r i a n c e i n t h e wind p a t t e r n s . of l a r g e r weather systems which predominates w i t h p e r i o d s o f l i g h t o r strong winds l a s t i n g The of the i n l e t . At other times, i t i s the effect f r o m one t o f o u r Squamish days. R i v e r c o n s t i t u t e s t h e main f r e s h water tributary H o u r l y d i s c h a r g e measurements a r e t a k e n a t t h e D a i s y L a k e Dam a t B r a c k e n d a l e , 25 km n o r t h o f S q u a m i s h Canada s t a t i o n 8GA22). The r i v e r (Water Survey o f discharge i s typically 3 100 m / s e c 3 in winter (May (November t o A p r i l ) a n d t y p i c a l l y .3.00 m / s e c i n summer t o September). The d a i l y d i s c h a r g e c a n be e x p e c t e d t o p e a k o c c a s i o n a l l y a t several times these values. discharg 3 o f t h e y e a r 1 9 7 3 o c c u r r e d o n O c t o b e r 28 w i t h a mean r a t e o f 1 1 7 0 m / s e c I.3 Earlier The h i g h e s t d a i l y i n v e s t i g a t i o n s o f Howe S o u n d ' s P h y s i c a l Many i n v e s t i g a t o r s h a v e v i s i t e d Howe S o u n d . gives a detailed list going back t o C a p t a i n Vancouver. Oceanography. Buckley (1977) In this study, r e f e r e n c e i s made o n l y t o r e c e n t i n v e s t i g a t i o n s w h i c h c o v e r e d b o t h b a s i n s and t h e e n t i r e water column, I n 1968, t h e M a r i n e S c i e n c e s Branch o f t h e Department E n v i r o n m e n t o f Canada c a r r i e d of Georgia which r e s u l t e d Ages, 1971). c o n t i n u o u s l y o r on a monthly a program basis. ofthe of observation of the Strait i n m o n t h l y c r u i s e s i n Howe S o u n d The I n s t i t u t e o f O c e a n o g r a p h y (Crean and has c a r r i e d out a program 5 of monthly c r u i s e s i n Howe S o u n d b e t w e e n S e p t e m b e r 1 9 7 1 a n d M a r c h 1 9 7 4 and the data are a v a i l a b l e The C o a s t a l Oceanography Group o f t h e I n s t i t u t e o f Ocean S c i e n c e a t Patricia ( I.O.U.B.C., 1 9 7 2 , e t c . ) Bay has o p e r a t e d c h a i n s o f c u r r e n t meters Howe S o u n d . 1972 i n Data Reports i n both basins of A s t a t i o n c l o s e t o Howe 4 was o c c u p i e d b e t w e e n November and F e b r u a r y 1974. The d e p t h s w h i c h were m o n i t o r e d were: 3 m ( G e o d y n e A - 8 5 0 v e c t o r a v e r a g i n g c u r r e n t m e t e r ) , 5, 1 0 , 1 5 , 2 0 , 30 and 150 m ( A a n d e r a a RCM-4 c u r r e n t m e t e r s ) . been p u b l i s h e d by B e l l sive vector The r e s u l t i n g d a t a have (1975) under t h e form o f h i s t o g r a m s and p r o g r e s - diagrams. These d a t a have been a n a l y z e d by B e l l (1973) and P i c k a r d ( 1 9 7 5 ) f r o m t h e p o i n t o f v i e w o f t h e e v o l u t i o n o f t h e Deep W a t e r erties and by B u c k l e y (1977) a l s o (1977) f o r t h e c u r r e n t meter d a t a . c a r r i e d o u t an experiment prop- Buckley w i t h r a d a r - t r a c k e d drogues t o study t h e dynamics o f t h e S u r f a c e Layer. T y p i c a l w i n t e r p r o f i l e s o f temperature Sound a r e p r e s e n t e d i n f i g u r e 3. and s a l i n i t y i n Howe They were o b t a i n e d a t s t a t i o n s Howe 3 ( O u t e r B a s i n ) a n d Howe 4 ( I n n e r B a s i n ) o n F e b r u a r y 5 a n d 6, 1974. water The p r o f i l e s illustrate t h a t t h e d e n s i t y o f t h e Howe S o u n d i s c o n t r o l l e d by s a l i n i t y temperature which i n c r e a s e s w i t h depth that of s a l i n i t y . i n c r e a s e s w i t h depth. I n f i g . 3, so t h a t i t s e f f e c t p a r t l y c o u n t e r a c t s A t o t h e r t i m e s o f t h e y e a r , t e m p e r a t u r e may w i t h depth over p a r t of the water decrease column b u t i t p l a y s a secondary i n d e t e r m i n i n g t h e d e n s i t y o f t h e Howe S o u n d water. role 6 Figure 3 also homogeneous b e l o w shows t h a t t e m p e r a t u r e a n d s a l i n i t y are very 100 m i n t h e I n n e r B a s i n compared t o what i s f o u n d a t s i m i l a r d e p t h i n t h e O u t e r B a s i n and compared t o what i s f o u n d i n b o t h b a s i n s a b o v e 100 m. Pickard (1975) has i n d i c a t e d that a majority of the i n l e t s of t h e B r i t i s h C o l u m b i a m a i n l a n d c o a s t show y e a r l y v a r i a t i o n s Deep W a t e r p r o p e r t i e s . These changes appear processes i n v o l v i n g water Water o f a few i n l e t s , from t h e S t r a i t to occur through advective of Georgia. I n t h e Deep such y e a r l y v a r i a t i o n s a r e n o t apparent; Deep W a t e r t h e r e may r e m a i n Howe S o u n d a p p e a r s because i n their of i t s shallow s i l l . the t r a p p e d f o r more t h a n a y e a r a t a t i m e . to c o n s t i t u t e a borderline case, Pickard (1975) presumably describes the evolution of t h e Deep W a t e r a t 2 0 0 m, a t s t a t i o n Howe 4, a s p r e s e n t i n g a saw t o o t h pattern. oxygen. Quick changes o c c u r i n t h e s a l i n i t y , They a r e f o l l o w e d by slow changes w h i c h a r e a t t r i b u t e d a d v e c t i v e p r o c e s s e s such as t u r b u l e n t ( f o r d i s s o l v e d oxygen). whether Pickard t o non- t r a n s f e r and b i o c h e m i c a l processes (1975) indicated t h a t i t was n o t c l e a r t h e Deep W a t e r i n Howe S o u n d u n d e r w e n t a n n u a l c h a n g e s o r more intermittent Bell ones. (1973) s t u d i e d Deep W a t e r r e p l a c e m e n t s i n t h e I n n e r B a s i n . He e x a m i n e d p r i n c i p a l l y tration temperature and d i s s o l v e d t h e e v o l u t i o n o f t h e d i s s o l v e d oxygen (D.O.) a n d s a l i n i t y a t d e p t h s o f 1 0 0 , 1 5 0 a n d 200 m. w a t e r v o l u m e s u c h a s t h e Deep W a t e r o f t h e I n n e r B a s i n w h i c h from s u r f a c e exchanges concenIn a i s isolated a n d s u n l i g h t , D.O. v a l u e s a r e e x p e c t e d t o decrease w i t h time under the influence of l o c a l biochemical processes. 7 Similarly, salinity fresher water B e l l argued i s expected to decrease w i t h time because from above g e t s t u r b u l e n t l y mixed t h a t w h e n e v e r D.0. W a t e r showed s i g n i f i c a n t water and He A t t h e 150 high r i v e r and (1973) suggested r u n o f f and the s i l l i n early volume and the variable. winds by ("Squamish w i n d s " ) . A of course, i s t h a t the o u t s i d e water t o be a s d e n s e a s , o r d e n s e r Deep W a t e r o f t h e I n n e r B a s i n . met The t h a t t h e s e i n f l o w s were t r i g g e r e d s t r o n g seaward l e v e l has to occur 200 m l e v e l s , m a j o r i n - t o o c c u r a t l e a s t e v e r y few y e a r s . preliminary condition for this, found near i n t o the Inner Basin's i n f l o w s appeared depth of p e n e t r a t i o n of the i n f l o w s appear Bell i n t h e I n n e r B a s i n ' s Deep f o u n d i t s way f o u n d a t t h e 100 m l e v e l , f r e q u e n t l y , a l l year round. flows appeared t h e Deep W a t e r . d e p a r t u r e s f r o m t h e i r downward t r e n d s , some from the Outer B a s i n had Deep W a t e r . salinity into some than the These c o n d i t i o n s a r e most l i k e l y to be winter. D u r i n g J u n e and J u l y 1 9 7 3 , B u c k l e y (1977) L a y e r o f Howe Sound w i t h n e a r s u r f a c e p r o f i l e s n i t y and w i t h r a d a r t r a c k e d s u r f a c e drogues. o f t h e h a l o c l i n e v a r i e d b e t w e e n 0 and studied the Surface o f t e m p e r a t u r e and He found that the 5 m during h i s experiment. sali- depth The h a l o c l i n e was s h a r p e s t n e a r t h e m o u t h o f t h e r i v e r a n d more diffuse f u r t h e r away. I t s d e p t h v a r i e d w i t h t i m e , l o n g i t u d i n a l and lateral positions. The sails b u l k o f B u c k l e y ' s e x p e r i m e n t was s e t b e t w e e n 0 and f o l l o w e d a meandering 2 m. He made w i t h d r o g u e s with found that the r i v e r d i s c h a r g e p a t t e r n over the i n l e t . During a short experiment, 8 Buckley used drogues w i t h s a i l s setat different an o u t f l o w a n d a s t r o n g r e t u r n f l o w w i t h The c o r e s were l o c a t e d on d i f f e r e n t their cores 5 m, i t was o n a v e r a g e g o i n g up i n l e t were l a r g e f l u c t u a t i o n s c e n t e r e d Buckley and c u r r e n t meter s t r i n g velocity. accounted f o r v a r i a t i o n s i n the Further down t h e i n l e t , e s t a b l i s h e d by the P a c i f i c a t 150 m. o f t h e c u r r e n t r e c o r d s was c o n c e n t r a t e d c y c l e s p e r day ( B u c k l e y , 1977). Buckley i n t h e band o f one t o showed t h a t a t i d a l model y i e l d e d a r a t i o o f t h e d i u r n a l v e l o c i t y v a r i a n c e had Oceano- The s p e c t r a l 2 the s e m i - d i u r n a l v a r i a n c e Layer. B a s i n o f Howe Sound h a d 6 m e t e r s l o c a t e d i n t h e u p p e r 30 m a n d o n l y o n e m e t e r b e l o w t h i s , o f 0.30. o f 0.31. The o t h e r prism 2 (m / s e c ) t o T h e c u r r e n t m e t e r a t 150 m y i e l d e d c u r r e n t m e t e r s , l o c a t e d i n t h e u p p e r 30 m, r a t i o s w h i c h w e r e q u i t e v a r i a b l e b u t a l w a y s l a r g e r t h a n 0.7. e x a m i n i n g t h e shape o f t h e s p e c t r a , B u c k l e y concluded o f w i n d s d e c r e a s e d w i t h d e p t h a n d became i n s i g n i f i c a n t W i n d s o v e r Howe Sound h a v e a s t r o n g By that the effect a t 150 m. d i u r n a l component w h i c h w o u l d e x p l a i n why t h e r a t i o o f d i u r n a l t o s e m i - d i u r n a l v a r i a n c e near the surface. there found t h a t n e a r t h e head o f t h e i n l e t , w i n d s , t i d e s g r a p h i c Group i n t h e I n n e r a ratio then a n d f o u n d t h a t a t 3 m, was t h e w i n d w h i c h d o m i n a t e d t h e c i r c u l a t i o n o f t h e S u r f a c e variance both a t 3.6 cm/sec w h i l e a t f i e l d which had comparable magnitudes. The two Buckley a t 4.2 cm/sec a n d a t 10 m, near zero v a r i a t i o n s i n the r i v e r discharge velocity it down i n l e t He f o u n d i n t h e u p p e r 5 m. sides of the i n l e t . examined t h e near s u r f a c e c u r r e n t meter r e c o r d s t h e c u r r e n t was o n a v e r a g e g o i n g depths. i slarger 9 The c u r r e n t m e t e r l o c a t e d a t 150 m r e c o r d e d ties o f 0.15 m/sec. (1973), routinely I n the c u r r e n t v e c t o r diagrams presented velociby Bell d u r i n g November a n d D e c e m b e r 1 9 7 3 , t h e r e was a c o n s i s t e n t r e s i d u a l current of the order towards the s i l l . d r i f t was f o u n d . maximum s i l l During Notice depth. o f .01 m/sec (roughly 1 km/day) J a n u a r y a n d F e b r u a r y 1 9 7 4 , no s u c h flowing consistent t h a t t h e c u r r e n t m e t e r i s l o c a t e d 80 m b e l o w I t i s not c l e a r whether the r e s i d u a l c u r r e n t i s r e a l o r whether i t i s an a r t i f a c t o f t h e c u r r e n t m e t e r and i t s m o o r i n g . 10 Chapter I I New A s p e c t s o f t h e O c e a n o g r a p h i c and Bell concerned Current Meter (1973), P i c k a r d (1975) and B u c k l e y m o s t l y w i t h t h e Deep W a t e r B a s i n ) and t h e S u r f a c e Layer temperature Data. (below sill o f Howe S o u n d . t h e depth range Water renewal earlier. Both of the f a l l i n the Inner h a s b e e n o b t a i n e d i n Howe o f 10 t o 100 m. t h e d a t a w e r e o b t a i n e d i n November 1 9 7 3 e i t h e r a Deep W a t e r r e n e w a l . depth, H o w e v e r , much o f t h e m i c r o s t r u c t u r e i n f o r m a t i o n which Sound comes f r o m (1977) have been M o r e o v e r , much o f during or shortly t h e 10 t o 100 m d e p t h r a n g e o f 1973 have r e c e i v e d l i t t l e after a n d t h e Deep attention T h i s c h a p t e r p r e s e n t s a n d d i s c u s s e s some d a t a r e l e v a n t t o t h e s e a s p e c t s o f t h e p h y s i c a l o c e a n o g r a p h y o f Howe S o u n d . II.1 The I n t e r m e d i a t e Water. The object of this s e c t i o n i s t o show b r i e f l y that there are r e g i o n s i n Howe S o u n d w h e r e t h e e v o l u t i o n o f o c e a n o g r a p h i c p r o p e r t i e s is c o n t r o l l e d m a i n l y by h o r i z o n t a l exchanges between t h e S t r a i t o f Georgia, the Outer study, the water Water". B a s i n and t h e I n n e r B a s i n . found F o r t h e purpose i n these r e g i o n s i s c a l l e d The d a t a p r e s e n t e d h e r e come f r o m of this the "Intermediate the monthly oceanographic c r u i s e s made b y t h e I n s t i t u t e o f O c e a n o g r a p h y o f t h e U n i v e r s i t y o f British C o l u m b i a b e t w e e n 1972 a n d 1974 ( I . O . U . B . C . , 1 9 7 2 , e t c . ) . F i g u r e 4 shows t h e t e m p e r a t u r e and b e l o w t i m e - s e r i e s o b s e r v e d a t 100 m a t s t a t i o n s Howe 2 a n d Howe 3 i n t h e O u t e r B a s i n . p r e s e n t s time s e r i e s o f temperature and s a l i n i t y a g e d b e t w e e n 20 a n d 75 m. from each b a s i n aver- T h e s t a t i o n s a r e Howe 3 ( O u t e r B a s i n ) a n d Howe 4.5 ( I n n e r B a s i n ) ( s e e f i g . 1 ) . The samples f r o m 2 0 , 3 0 , 50 a n d 75 m w e r e a v e r a g e d w i t h w e i g h t s o f 2, 3, 4, 4 t o r e f l e c t the depth i n t e r v a l r e p r e s e n t e d by each v a l u e . time-series of temperature, s a l i n i t y , o b t a i n e d a t 100 m a n d b e l o w Figure 5 the size of Figure 6 presents the sigma-t and d i s s o l v e d oxygen i n t h e I n n e r B a s i n (Howe 4 . 5 ) . F i g u r e 4 shows l a r g e v a r i a t i o n s o f t e m p e r a t u r e o n a t i m e s c a l e which i sw e l l r e s o l v e d by the monthly rate of sampling. The v a r i a t i o n s a r e a r e f l e c t i o n of. those t a k i n g p l a c e i n the S t r a i t o f Georgia ( P i c k a r d , 1975) and i l l u s t r a t e t a k i n g p l a c e between t h e S t r a i t the r e l a t i v e l y free o f G e o r g i a and t h e Outer m a i n l y t h r o u g h t h e Queen C h a r l o t t e exchanges Basin, Channel. I n f i g u r e 5, t h e t e m p e r a t u r e time-series show t h a t t h e v a r i a - t i o n s w h i c h o c c u r b e t w e e n 20 a n d 75 m i n b o t h b a s i n s f o l l o w a p a t t e r n similar to that which i s observed below 100 m i n t h e O u t e r B a s i n . The r a n g e o f t h e t e m p e r a t u r e v a r i a t i o n s a t Howe 4.5 ( I n n e r B a s i n ) i s slightly s m a l l e r t h a n t h a t a t Howe 3 ( O u t e r B a s i n ) b u t no s i g n i f i c a n t l a g i s o b s e r v e d b e t w e e n t h e two t i m e - s e r i e s . series of f i g . 5 also The two s a l i n i t y t r a c k each o t h e r q u i t e c l o s e l y . i n s t a n c e s , l a r g e changes i n s a l i n i t y time- In several a r e o b s e r v e d i n b o t h b a s i n s by t h e same c r u i s e s a n d t h u s t h e y may t h a n one m o n t h . O n l y i n f l o w s o f s a l i n e w a t e r may in salinity this occur w i t h i n a time i n t e r v a l a n d , i n Howe S o u n d , o n l y t h e S t r a i t s a l i n e water. Thus t h e v a r i a t i o n s result one i n increases o f G e o r g i a may i n s a l i n i t y and o b s e r v e d a b o v e 75 m i n b o t h b a s i n s r e s u l t f r o m e x c h a n g e s Strait shorter provide temperature with the o f G e o r g i a w h i c h c a n t a k e p l a c e on a t i m e s c a l e s m a l l e r than month. I n f i g u r e 6, and d i s s o l v e d oxygen the t i m e - s e r i e s of temperature, s a l i n i t y , a t 125 m a n d b e l o w show p e r i o d s o f s t e a d y s e p a r a t e d b y p e r i o d s o f l a r g e r a n d more a b r u p t c h a n g e . d e s c r i b e d as " s a w - t o o t h " by P i c k a r d (1975). Bell trend This pattern i s (1973) c o r r e s p o n d s t o p e r i o d s when d i f f u s i v e p r o c e s s e s d o m i n a t e showed t h a t i t and when t h e r e a r e i n f l o w s f r o m t h e O u t e r B a s i n , o v e r t h e s i l l to periods and into t h e I n n e r B a s i n ' s Deep W a t e r . This pattern d i f f e r s markedly one w h i c h was 4 a n d 5, f o r t h e O u t e r B a s i n a n d observed i n f i g . p a r t o f t h e I n n e r B a s i n a t 75 m a n d sigma-t from the the above. The p r e c e d i n g d i s c u s s i o n shows t h a t t h e I n t e r m e d i a t e W a t e r , as d e f i n e d about i n the f i r s t 20 m a n d paragraph of t h i s the bottom section, i n the Outer Basin. i s found between In the Inner B a s i n , i t i s c h o s e n t o p u t t h e l o w e r l i m i t o f t h e I n t e r m e d i a t e W a t e r a t 100 since i n f i g . 6, t h e w a t e r a t 100 m h a d a n e v o l u t i o n m a r k e d l y f r o m t h e w a t e r a t 125 m a n d b e l o w . Inner Basin i s therefore c a l l e d the s u r f a c e , different The w a t e r a t 125 m a n d b e l o w t h e "Deep W a t e r " i n this i t i s n o t c l e a r a t what d e p t h exchanges o f G e o r g i a become l e s s i m p o r t a n t t h a n t h e v e r t i c a l with thesis. the turbulent m i n the Near Strait transfer of t h e l o c a l f r e s h water most o f t h e f r e s h w a t e r limit for run off. was f o u n d Buckley showed t h a t , i n t h e u p p e r 10 m. Thus t h e upper o f t h e I n t e r m e d i a t e W a t e r may b e s e t a t 10 m b e l o w t h e s u r f a c e t h e purpose of t h i s study. Figure 7 presents a s e c t i o n o f Howe S o u n d w h e r e t h e S u r f a c e L a y e r , and i n June 1973, long-channel the Intermediate Water t h e Deep W a t e r a r e shown. II.2 A Deep W a t e r r e n e w a l In the F a l l o f 1973, I n n e r B a s i n o f Howe S o u n d . temperature i n the F a l l a Deep W a t e r r e n e w a l renewal occurred i n the On November 20 a n d 2 1 , 1 9 7 3 a c r u i s e made m i c r o s t r u c t u r e observations i n the Inner Basin. i n t e r p r e t a t i o n of the r e s u l t i n g requires o f 1973. data (presented i n the next The chapters) t h a t some o f t h e i n f o r m a t i o n a v a i l a b l e f o r t h e Deep W a t e r be examined first. F i g u r e s 8, 9 a n d 10 p r e s e n t l o n g - c h a n n e l s e c t i o n s o f temper- a t u r e , s a l i n i t y a n d d i s s o l v e d o x y g e n (D.0.) o b t a i n e d w i t h b o t t l e on S e p t e m b e r 2 0 , 1 9 7 3 , o n November 1 3 , 1 9 7 3 a n d o n J a n u a r y (I.O.U.B.C., 1 9 7 3 ) . F i g u r e 11 p r e s e n t s t h e t e m p e r a t u r e N-S c o m p o n e n t o f t h e v e l o c i t y meter c h a i n l o c a t e d near to November 1 5 . ward f l o w . North casts 2 2 , 1974 r e c o r d and t h e r e c o r d o b t a i n e d a t 150 m b y a c u r r e n t s t a t i o n Howe 4, f o r t h e p e r i o d o f O c t o b e r 25 P o s i t i v e c u r r e n t v a l u e s i n f i g . 11 i n d i c a t e a n o r t h l i e s approximately i n an u p - i n l e t d i r e c t i o n (fig.l). The Deep W a t e r d i s t r i b u t i o n o f S e p t e m b e r 2 0 , 1973 t y p i c a l o f t h a t w h i c h was (I.O.U.B.C., 1 9 7 3 ) . e n c o u n t e r e d d u r i n g the p r e v i o u s s i x months I t i s interesting v a l u e s are found a l o n g the bottom pleth. to n o t i c e that are found i n the b o t t l e c o n t r a s t s o f up The m o n t h l y density o f 7.9 A t e m p e r a t u r e minimum i s f o u n d a t 100 m t o 8.0 e r a t u r e a t 75 m c h a n g e d °C C° 1973). (fig.8). stayed i n s i n c e t h e p r e v i o u s J u n e w h i l e t h e temp- f r o m c o o l e r t o warmer t h a n t h i s A t 125 m a n d b e l o w , D.O. difference c r u i s e s show t h a t t h e t e m p e r a t u r e a t 100 m h a s the v i c i n i t y 1973). t o 0.09 cast data (I.O.U.B.C, T h e y a r e o f o p p o s i n g s i g n a n d no m e a s u r a b l e r e s u l t s f r o m them. the lowest p r o f i l e r a t h e r t h a n any o t h e r i s o - A l s o , a l o n g a same d e p t h l e v e l , a n d 0.009 °/oo (fig.9) i s the t i m e - s e r i e s i n d i c a t e a b r u p t change i n p r o p e r t y has o c c u r r e d (see f i g . 6 ) (I.O.U.B.C, t h a t no large or s i n c e the p r e v i o u s February. The November 1 3 , 1973 Deep W a t e r d i s t r i b u t i o n m a r k e d l y from t h a t o f September. two d i s t i n c t water masses. One The I n n e r B a s i n i s now p r o p e r t i e s a s t h e w a t e r w h i c h was a n d w i t h D.O. now called t h a n 8.3 The C, i n the Outer B a s i n , 1973). less s a l i n e t h a n 30.5 ml/1). A t Howe 4, called t h e "New Water" parts /oo This water i s towards i t o c c u p i e s the whole w a t e r column different to t h e same o c e a n o g r a p h i c o t h e r w a t e r mass i s f o u n d b e l o w I t s properties are d i s t i n c t l y W a t e r a n d i t i s now I t has t h a n 2.5 a n d a b o v e 50 m t h r o u g h t h e I n n e r B a s i n . and o c c u p i e d by p r e v i o u s l y found i n the deepest concentrations smaller the " O l d Water". differs m a s s o c c u p i e s t h e d e p t h r a n g e o f 50 200 m i n t h e u p - i n l e t p a r t o f t h e b a s i n . of the Inner B a s i n ( c o l d e r (fig.9) the 200 m sill (I.O.U.B.C, from those of the Old (temperature higher than 8.5 °C, s a l i n i t y higher t h a n 2.4 ml/1). The t h a n 30.5 °/oo, sigma-t v a l u e D.O. concentration higher of b o t h water masses i s between 3 23.67 and too 23.70 kg/m s m a l l t o be The and t h e d e n s i t y s t r a t i f i c a t i o n b e l o w 100 accurately J a n u a r y 22, presents two t h e D.O. distribution. 1974 Deep W a t e r d i s t r i b u t i o n d i s t i n c t water masses. The the cores d i f f e r e n c e has 100 D.O. m and values at that The d e c r e a s e d f r o m 0.5 d e c r e a s e d f r o m 0.10 less, This the are higher, indicating two one well in w a t e r masses i s t o 0.3 °/oo C° t o 0.08 are lower and °/oo. the At salinity depths t h a t exchanges have been the continuing level. t h e Deep W a t e r r e n e w a l , i n s t a l l e d b e l o w 30 m. t h e 150 Buckley Howe 4 m c u r r e n t m e t e r was (1977) , u s i n g o n l y the the essentially b e t w e e n November 9 and 13. g r e s s i v e v e c t o r d i a g r a m s ( B e l l , 1975) i n s t e a d of the u s u a l down-inlet this chapter. velocity and During show a n e t t h e N-S pro- up-inlet current mentioned earlier component o f t h e current the temperature r e c o r d obtained l o c a t e d a t 150 place t h i s p e r i o d , the " d r i f t " w h i c h was F i g . 11 p r e s e n t s only velocity r e c o r d o f t h i s m e t e r , d e d u c e d t h a t t h e Deep W a t e r i n f l o w t o o k in of t h a n i n J a n u a r y and In the c u r r e n t meter c h a i n l o c a t e d near s t a t i o n during still temperature d i f f e r e n c e between C° s a l i n i t y values (fig.10) shows p a r t i c u l a r l y c o n t r a s t between the t h a n i n November ( f i g . 9 ) . has is estimated. smaller two m from the c u r r e n t meter m. F i g u r e 11 shows t h a t , s t a r t i n g w a t e r " p u l s e s " o c c u r r i n g o n c e a day O c t o b e r 27, a t 150 t h e r e a r e warm m u n t i l O c t o b e r 31. The o n l y p o s s i b l e s o u r c e o f w a t e r warmer coming from t h e Outer B a s i n t h a n 8.4 ( f i g . 8 and 9 ) . t h e Deep W a t e r r e n e w a l s t a r t e d b e f o r e C i s c l e a r l y New Water T h u s , f i g . 11 shows o r o n O c t o b e r 27. that I t i s not c l e a r w h e t h e r t h e warm w a t e r was a d v e c t e d h o r i z o n t a l l y o r v e r t i c a l l y past t h e c u r r e n t m e t e r a n d no e s t i m a t e of the volume of the i n f l o w c a n b e made f r o m t h e c u r r e n t m e t e r r e c o r d s alone. S t a r t i n g November 2, t h e 150 m c u r r e n t m e t e r becomes inantly i m m e r s e d i n warm w a t e r . variations pattern. further late The c u r r e n t v e l o c i t y than p r e v i o u s l y and o f t e n p r e s e n t s larger a s o r t of "square The r e a s o n s f o r t h i s a r e n o t c l e a r . i n f l o w s are o c c u r r i n g a t that time, shows predom- One can speculate b u t one c a n a l s o wave" that specu- t h a t t h e Deep W a t e r i s r e s p o n d i n g t o a c h a n g i n g p a t t e r n o f forcing functions (surface winds, t i d e s , r i v e r r u n o f f ) and t h a t t h e 150 m c u r r e n t m e t e r h a s become i m m e r g e d p r e d o m i n a n t l y i n New W a t e r a r e s u l t o f t h i s r a t h e r t h a n a s a r e s u l t o f new as inflows. I n summary, t h e o c e a n o g r a p h i c t i m e - s e r i e s show t h a t a Deep Water renewal o c c u r r e d b e t w e e n S e p t e m b e r a n d November 1 9 7 3 . current meter temperature record had a t 150 m i n d i c a t e s t h a t a t l e a s t s t a r t e d o n O c t o b e r 27. record i s of l i t t l e use. The New W a t e r o c c u p i e s t h e Deep W a t e r a n d , n e a r t h e c e n t e r Inner Basin clear were o b t a i n e d that of the channel, data which are presented r e n e w a l had t a k e n place. velocity the part of the Some o f t h e t e m p e r - i n the f o l l o w i n g s h o r t l y a f t e r November 1 8 , 1 9 7 3 . these data were o b t a i n e d the renewal t h e l o w e r 200 m o f l o c a t e d b e t w e e n Howe 4 a n d t h e s i l l . ature microstructure chapters The c u r r e n t m e t e r The a f t e r the bulk I t i s now o f t h e Deep W a t e r Chapter I I I M i c r o s t r u c t u r e methods and d a t a p r o c e s s i n g . III.l P r o b e s and In resolution. the c o u r s e of p r e v i o u s work i n m i c r o s t r u c t u r e , has o f t e n been f e l t f o r a set of l i g h t , microstructure profilers. was The s i m p l e and r u g g e d T h i s was to The o r more c o m p l e x i n s t r u m e n t s . t e m p e r a t u r e m i c r o s t r u c t u r e p r o f i l e r s was i d e n t i c a l probes nicknamed Osborn (1977). The resulted The difficult d e s i g n of i n 1972 at the spherical floats probes are d e s c r i b e d i n d e t a i l A s c h e m a t i c d r a w i n g o f one i s shown i n f i g . The t h e r m i s t o r i s a m e t a l oxyde microbead with t y p i c a l d i a m e t e r o f 150 m i c r o n s , c o a t e d w i t h a f i l m of w i t h a t h i c k n e s s of about insulation 15 m i c r o n s f o r e l e c t r i c a l the occurrence of e l e c t r i c a l leaks into t h e r m i s t o r s u p p o r t arms ( n o t t h e m i c r o b e a d s ) The 12. p r o b e s p r o v i d e a s u p p o r t f o r a t h e r m i s t o r b r i d g e and its electronics. To r e d u c e light i n a set of three "Pumpkin" f o r the orange which p r o v i d e s t h e i r buoyancy. in and initiated probes temperature m i c r o s t r u c t u r e by making s i m u l t a n e o u s p r o f i l e s . U n i v e r s i t y of B r i t i s h Columbia temperature f i r s t m o t i v a t i o n i n u s i n g such to i n v e s t i g a t e the h o r i z o n t a l c h a r a c t e r i s t i c s of do w i t h e a r l i e r the need Paralene-C sea water, were c o a t e d w i t h (fig.12) the glyptol. frequency response of such a t h e r m i s t o r moving i n a has been s t u d i e d by L u e c k , Hertzman and O s b o r n ( 1 9 7 7 ) . a For a fluid typical v e l o c i t y o f 20 c m / s e c , t h e i r c a l c u l a t i o n s i n d i c a t e t h e 3 dB p o i n t i n s p a t i a l r e s o l u t i o n t o b e c l o s e t o 2 cm. The of f i n e present study c o n s i s t s o f an i n v e s t i g a t i o n o f t h e types s t r u c t u r e a n d m i c r o s t r u c t u r e f e a t u r e s e n c o u n t e r e d i n Howe Sound a n d o f t h e i r h o r i z o n t a l v a r i a b i l i t y . i s n o t based on q u a n t i t a t i v e e s t i m a t e s vertical temperature gradient. The a n a l y s i s o f t h e d a t a of the t o t a l variance Therefore, the individual of the frequency r e s p o n s e o f e a c h t h e r m i s t o r was n o t m e a s u r e d a n d no a t t e m p t h a s b e e n made t o c o r r e c t t h e h i g h f r e q u e n c y The roll-off. t h e r m i s t o r was p a r t o f a W h e a t s t o n e b r i d g e . The e l e c t r o - n i c package o f t h e probe generated a temperature s i g n a l and t h e time derivative of this signal. These were r e l a y e d t o t h e s u r f a c e a S i p p i c a n XWL ( E x p e n d a b l e W i r e L i n k ) u s i n g s u r f a c e , these and digitized a typical per s i g n a l s were r e c o r d e d through I R I G FM c h a n n e l s . At the on tape t o be l a t e r p l a y e d a t a r a t e o f 250 s a m p l e s p e r s e c o n d p e r c h a n n e l . back For s i n k i n g r a t e o f 20 c m / s e c , t h i s c o r r e s p o n d s t o 12.5 s a m p l e s cm. The noise present i n t h e s i g n a l s has been e s t i m a t e d from t h e deep p a r t s o f t h e p r o f i l e s w h e r e no m e a n i n g f u l s i g n a l c o u l d b e M o s t o f t h e n o i s e v a r i a n c e was i n t h e h i g h e r instrument, a t wave n u m b e r s h i g h e r t h a n 2 cm frequency detected. range o f t h e A t depths greater t h a n 100 m, i t i n c r e a s e d a p p r e c i a b l y w i t h d e p t h b e c a u s e o f t h e i n c r e a s i n g l e n g t h o f t h e XWL l i n k . are: N e a r 150 m, t y p i c a l rms n o i s e 0.01 C° i n t h e t e m p e r a t u r e c h a n n e l channel. values a n d 0.03 C°/m i n t h e g r a d i e n t During t h e F e b r u a r y 1974 c r u i s e , t h e m i c r o s t r u c t u r e were used i n p a i r s . o f 3, 10 a n d 20 m. before The They were r e l e a s e d w i t h a h o r i z o n t a l s e p a r a t i o n They f e l l freely t o a d e p t h o f 150 t o 200 m r e l e a s i n g some b a l l a s t w e i g h t a n d f l o a t i n g b a c k t o t h e s u r f a c e . probes surfaced w i t h separations of t h e probes a t r e c o v e r y launch (see Table I ) . b e t w e e n 1 a n d 75 m. During w i t h i n one m i n u t e o f e a c h III.2 the descent, struct processing. The i n processing step rough v e r t i c a l ture s i g n a l versus the probes probably time. stayed r e a c h e d t h e d e p t h o f 100 m the d i g i t i z e d d a t a was t o c o n - temperature p r o f i l e s by p l o t t i n g the tempera- These p r o f i l e s were t h e n compared w i t h of temperature versus a Bissett-Berman spacing other. Method o f d a t a first The d i d not c o r r e l a t e with the spacing at w i t h i n 3 t o 40 m o f e a c h o t h e r a n d t h e y files probes depth obtained pro- a t t h e same l o c a t i o n w i t h 9060 s e l f - c o n t a i n e d STD r e c o r d e r . Salient features of t h e p r o f i l e s were matched and t h e i r depths and t e m p e r a t u r e s on t h e STD c h a r t w e r e n o t e d . By a s s u m i n g t h e Pumpkin s i n k i n g r a t e t o be c o n s t a n t , t h e matched f e a t u r e s p r o v i d e d (± 5 %•).' a d e p t h s c a l e w i t h an a c c u r a c y When t h e P u m p k i n s h a d b e e n u s e d i n p a i r s , the analysis r e q u i r e d y e t a f i n e r match o f t h e depth s c a l e s so t h a t smaller than s e v e r a l metres c o u l d be p a i r e d w i t h o u t of ± 3 m features ambiguity. For this, two s a l i e n t f e a t u r e s o f one p r o f i l e were a s s i g n e d depths as t h e e q u i v a l e n t f e a t u r e s on t h e o t h e r and t h e same p r o f i l e of the pair t h e d e p t h s c a l e was r e c o n s t r u c t e d b y l i n e a r interpolation. The r e s i s t a n c e o f t h e t h e r m i s t o r s d e c r e a s e s a p p r o x i m a t e l y e x p o n e n t i a l l y when t e m p e r a t u r e i n c r e a s e s . The e x p o n e n t i a l c i e n t o f t h i s r e s p o n s e was known a n d i t was u s e d m a t c h e d f e a t u r e s o f t h e STD p r o f i l e coeffi- together with the to construct a temperature cali- b r a t i o n w i t h a n a c c u r a c y o f + 0.3 C° i n t h e r a n g e o f 6 t o 9 °C. The g a i n o f t h e d i f f e r e n t i a t o r paring i t s s i g n a l with the temperature s i g n a l . calibration, the differentiator i n g r a t e were used into a vertical Overall circuit g a i n and t h e e s t i m a t e d to scale the d i f f e r e n t i a t e d temperature gradient Then t h e t e m p e r a t u r e temperature sink- signal (°C/m) w i t h a n a c c u r a c y o f + 1 0 % . profiles: For tized c i r c u i t was c h e c k e d b y com- c o n s t r u c t i n g o v e r a l l p r o f i l e s o f each drop, t h e d i g i - t e m p e r a t u r e and g r a d i e n t points per channel. d a t a were grouped Each b l o c k contained 0.4 m o f t h e w a t e r c o l u m n . i n blocks i n f o r m a t i o n from o f 512 about F o r e a c h b l o c k , a mean t e m p e r a t u r e , a mean t e m p e r a t u r e g r a d i e n t a n d a rms t e m p e r a t u r e g r a d i e n t w e r e c a l c u lated. E a c h o v e r a l l p r o f i l e c o n s i s t s o f up t o 550 o f t h e s e p l o t t e d w i t h the depth s c a l e obtained fashion. i n the previously values described E x a m p l e s o f s u c h p r o f i l e s a r e f o u n d i n f i g u r e s 14 t o 2 0 . - Detailed profiles: I t was a l s o p o s s i b l e t o p l o t t h e o r i g i n a l d i g i t i z e d of t e m p e r a t u r e and g r a d i e n t s c a l e d i n °C a n d °C/m i b r a t i o n method a s f o r t h e o v e r a l l p r o f i l e . before using the c a l i b r a t i o n , the gradient a s y n t h e t i c temperature s i g n a l . T h i s was using However, s i g n a l was t h e same i n this T h e n , t h e new s i g n a l were t e m p e r a t u r e s i g n a l and t h e g r a d i e n t 5 to 1 m per inch. The s i g n a l was By t h i s method, t e m p e r a t u r e s i g n a l was v i r t u a l l y t h a n 0.005 C° o v e r s e p a r a t i o n s into compared w i t h t h e o r i g i n a l o f f s e t was the c a l i b r a t i o n . cal- case, integrated t e m p e r a t u r e s i g n a l and t h e e f f e c t o f t h e g r a d i e n t using signal removed. scaled then p l o t t e d with s c a l e s of the high frequency noise of the removed and a r e s o l u t i o n o f b e t t e r o f a f e w cm was r o u t i n e l y achieved. E x a m p l e s o f t h i s a r e f o u n d i n f i g . 21 t o 2 4 . III.3 Summary o f t h e d a t a . Two filers c r u i s e s w e r e made w i t h i n Howe S o u n d . T h e y w i l l be d i s c u s s e d III.3a) Here, the r e s u l t i n g data i n more d e t a i l s are b r i e f l y pro- presented. i n C h a p t e r s I V a n d V. The November 1973 c r u i s e : The f i r s t c r u i s e was made b e t w e e n November 19 a n d 2 3 , 1 9 7 3 . S e v e n P u m p k i n d r o p s w e r e made. 13. the Pumpkin m i c r o s t r u c t u r e T h e i r l o c a t i o n s a r e shown i n f i g u r e The r e s u l t i n g o v e r a l l p r o f i l e s a r e p r e s e n t e d i n f i g . 14 t o 2 0 . T a b l e I I g i v e s t h e v a l u e s o f . t h e mean s q u a r e t e m p e r a t u r e g r a d i e n t found i n each drop (not c o r r e c t e d f o r the l i m i t e d response of the i n - s t r u m e n t s ) t o g e t h e r w i t h t h e l o c a t i o n a n d t i m e a t w h i c h e a c h d r o p was made. N o t i c e t h a t D r o p s P-10 a n d P-12 t o P-15 c o n s t i t u t e a t i m e s e r i e s o f p r o f i l e s made a t s t a t i o n Howe 4. Two d e t a i l e d p r o f i l e s f r o m D r o p P-12 a n d two f r o m D r o p P-13 a r e p r e s e n t e d i n f i g u r e s 21 t o 24. D u r i n g t h e November 1 9 7 3 c r u i s e , w e r e a l s o made a n d t h e y r e s u l t e d channel sections. a l a r g e number o f STD c a s t s i n s e v e r a l c r o s s - c h a n n e l and l o n g - One l o n g - c h a n n e l s e c t i o n i s p r e s e n t e d i n f i g . 25 a n d c r o s s c h a n n e l s e c t i o n s made a t Howe 4 a n d Howe 4.7 a r e p r e s e n t e d in fig. I I I . 3 b) 26 a n d 2 7 . The F e b r u a r y 1974 c r u i s e : The and 8, 1 9 7 4 . second cruise i n Howe Sound was made b e t w e e n F e b r u a r y 4 T h i s t i m e , b o t h b a s i n s were v i s i t e d two p r o b e s w e r e u s e d simultaneously. and, f o reach Table I l i s t s w h i c h w e r e made i n F e b r u a r y 1 9 7 4 t o g e t h e r w i t h t h e i r drop, a l l the drops time and l o c a t i o n and w i t h t h e s e p a r a t i o n o f t h e p r o b e s a t l a u n c h a n d a t r e c o v e r y . F i g . 28 shows t h e l o c a t i o n o f t h e d r o p s o n a map o f Howe S o u n d . all p r o f i l e s o f the drops a r e presented i n f i g . lists, f o reach drop, the temperature 29 t o 3 3 . The o v e r Table I I I change found a c r o s s t h e I n t e r - m e d i a t e W a t e r a n d t h e mean s q u a r e g r a d i e n t m e a s u r e d t h r o u g h i t (without c o r r e c t i o n f o r the response of the probes). F i g u r e s 34 t o 37 p r e s e n t t h e deep p a r t o f t h e p r o f i l e s o f d r o p s 7 t o 10 w i t h a n e x p a n d e d t e m p e r a t u r e out t h e s m a l l temperature c o n t r a s t s found Fig. 38 c o m p a r e s STD p r o f i l e s a n d o n F e b r u a r y 4, 1974 a t Howe 4. scale i n order to bring there. t a k e n on J a n u a r y 2 2 , 1974 F i g . 39 shows a l o n g c h a n n e l STD s e c t i o n made i n t h e I n n e r B a s i n d u r i n g t h e F e b r u a r y 1 9 7 4 c r u i s e a n d fig. 40 shows a c r o s s - c h a n n e l s e c t i o n made a t Howe 4. Chapter IV Temperature S t r u c t u r e i n Howe S o u n d i n November 1 9 7 3 a n d F e b r u a r y 1 9 7 4 The " P u m p k i n " m i c r o s t r u c t u r e profilers yielded about t h e s t r u c t u r e o f t h e d i s t r i b u t i o n tens the of temperature a t scales of o f m e t r e s a s w e l l a s a t s c a l e s o f a f e w cm. overall In this s t r u c t u r e o f the temperature d i s t r i b u t i o n i s e x a m i n e d b y means o f l o n g - c h a n n e l information and c r o s s - c h a n n e l chapter, i n Howe S o u n d sections of temperature p r o f i l e s . Much o f t h e s t r u c t u r e s r e v e a l e d b y t h e p r o f i l e s b e l o n g t o what G a r g e t t (1976) c a l l s ture (see a l s o s e c t i o n 1.1). provide profiles from t h e s c a l e s of the larger scale picture provided profiles. T e m p e r a t u r e s t r u c t u r e i n November 1 9 7 3 . Six section S e c o n d l y , t h e rms g r a d i e n t and p u t t i n g i t i n t o the temperature IV.1 s t r u c t u r e " o f tempera- a c r u d e way o f t a k i n g some i n f o r m a t i o n microstructure by the "fine Pumpkin o v e r a l l profiles ( f i g . 2 5 ) a n d two c r o s s - c h a n n e l a r e u s e d h e r e t o show t h e d i s t r i b u t i o n ture gradient i n the Inner Basin B o t t l e cast data ( f i g . 14 t o 2 0 ) , o n e STD s e c t i o n s long-channel ( f i g . 26 a n d 2 7 ) o f t e m p e r a t u r e a n d rms t e m p e r a - o f Howe S o u n d i n November 1 9 7 3 . c o l l e c t e d o n November 1 3 , 1 9 7 3 ( f i g . 9) showed t h a t the water p r e s e n t b e f o r e t h e r e n e w a l , c a l l e d O l d Water, h a d t e m p e r a t u r e s l o w e r t h a n 8.4 °C w h i l e c a l l e d New W a t e r , the recently arrived h a d t e m p e r a t u r e s o f 8.6 °C o r m o r e . A t s t a t i o n Howe 3.8, j u s t inside the s i l l , P - l l was made o n November 2 1 , 1 9 7 3 ( p r o f i l e fig.13). Below over t h e whole t h e Pumpkin i n fig.15, drop location i n 20 m, t e m p e r a t u r e s b e t w e e n 8.6 a n d 8.8 °C a r e f o u n d profile, indicating t h a t New W a t e r i s p r e s e n t t h e r e . B e t w e e n 20 a n d 80 m, t h e r e a r e many l a y e r s o f v a r y i n g with water, temperature t h i c k n e s s e s o f 1 t o 10 m. A t s t a t i o n Howe 4, a c r o s s - c h a n n e l STD s e c t i o n was made (fig.26). T h e p r o f i l e made o n t h e s o u t h - e a s t e r n s i d e o f t h e c h a n n e l shows t e m p e r a t u r e s o f 8.6 t o 8.8 °C e v e r y w h e r e that this side of the i n l e t b e l o w 30 m, i s o c c u p i e d b y New W a t e r . indicating The p r o f i l e made o n t h e n o r t h - w e s t e r n s i d e o f t h e c h a n n e l shows w a t e r o f 8.3 t o 8.5 °C.between 75 a n d 175 m, i n d i c a t i n g p a r t o f t h e water column. b y New W a t e r . t h a t O l d Water o c c u p i e s t h a t The r e s t o f t h e w a t e r c o l u m n i s occupied T h e p r o f i l e made i n t h e c e n t e r o f t h e c h a n n e l a l s o shows O l d W a t e r i n t h e same d e p t h r a n g e w i t h a 20 m t h i c k layer of New W a t e r n e a r 100 m d e p t h . D r o p s P-10 a n d P-12 t o P-15 w e r e a l s o made a t Howe 4, n e a r the c e n t r e o f t h e c h a n n e l ( f i g . 1 4 and f i g . 1 6 P-15 in w e r e made a t h o u r l y i n t e r v a l s t o 20). (Table I I ) . Drops On t h e s e P-12 t o profiles, t h e d e p t h r a n g e o f 30 t o 100 m, t h e r e a r e many t e m p e r a t u r e t i o n s a t s c a l e s o f 1 t o 30 m. Even t h e t h i c k e r be t r a c e d o n two s u c c e s s i v e p r o f i l e s . "layers" often variacannot I n some c a s e s , t h e t e m p e r a t u r e of the " l a y e r s " At a s s o c i a t e s them w i t h O l d W a t e r o r New W a t e r . s t a t i o n Howe 4.3, a n o t h e r made ( n o t shown h e r e ) . and STD c r o s s - c h a n n e l s e c t i o n was I n i t , New W a t e r was f o u n d a b o v e 100 m; i n b e t w e e n t h e r e was O l d W a t e r . made n e a r t h e S-E s i d e o f t h e c h a n n e l , 75 a n d 150 m o n l y . side of the channel t h e O l d W a t e r was f o u n d (fig.20). I n a l l these o n l y b e l o w 200 m a n d a b o v e 50 m. P-16 or "old". p r o f i l e s , New W a t e r was B e t w e e n 50 a n d 75 m, c l a s s i f i e d as B e t w e e n 30 a n d 75 m, t h e t e m p e r a t u r e looked very between ( f i g . 2 7 ) a n d D r o p P-16 was made n e a r t h e S-E t h e w a t e r o n t h e STD p r o f i l e s c o u l d n o t b e r e a d i l y "new" I n t h e STD p r o f i l e A t s t a t i o n Howe 4.7, o n e STD p r o f i l e was made o n each s i d e o f t h e channel a g a i n found o n l y b e l o w 200 m similar p r o f i l e o f drop t o t h e p r o f i l e s o b t a i n e d a t s t a t i o n Howe 4 ( s e e f o r i n s t a n c e P-13 i n f i g . 1 9 ) . I n D r o p s P-10 t o P - 1 6 , two a s p e c t s o f t h e rms g r a d i e n t files strike at first "bursts" or "patches" Secondly, little occur Firstly t h e rms g r a d i e n t o c c u r s i n w h i c h appear t o be a t most a few m e t r e s t h e r e a r e " q u i e t " r e g i o n s w h e r e , f o r up t o 50 m, rms g r a d i e n t i s f o u n d . The r e g i o n s w i t h l i t t l e i n r e g i o n s where t h e temperature Examination sharp glance. temperature pro- i s uniform with thick. very rms g r a d i e n t depth. o f a n y o f t h e p r o f i l e s a l s o r e v e a l s t h a t some c h a n g e s a r e a c c o m p a n i e d b y no l a r g e rms g r a d i e n t v a l u e s a n d a l s o t h a t some m i n o r t e m p e r a t u r e changes (where t h e l o c a l mean g r a d i e n t i s p e r h a p s w e a k e r ) show v e r y h i g h rms g r a d i e n t intensities. Table I I presents t h e mean s q u a r e g r a d i e n t v a l u e s found i n each drop below ~*3 o 25 x 10 a b o u t 20 m. The a v e r a g e v a l u e f o r a l l d r o p s i s 2 ( C/m) . The v a l u e s f o u n d i n i n d i v i d u a l drops v a r y from this v a l u e b y up t o a f a c t o r o f t w o . M o s t o f t h e v a r i a n c e o f t h e g r a d i e n t comes f r o m t h e u p p e r 100 m, i n t h e r e g i o n w h e r e t h e r e a r e a l s o many temperature v a r i a t i o n s . Near a n d p a t c h e s o f rms g r a d i e n t . signif icantly sition IV.2 deeper 200 m, some d r o p s show a t e m p e r a t u r e U n f o r t u n a t e l y , none o f t h e p r o b e s than t h i s . On t h e STD p r o f i l e s , rise went there i s a tran- f r o m O l d W a t e r t o New W a t e r n e a r 200 m. Temperature s t r u c t u r e i n F e b r u a r y 1974. D u r i n g t h e s e c o n d m i c r o s t r u c t u r e c r u i s e i n Howe S o u n d , b e t w e e n F e b r u a r y 4 a n d 8, 1 9 7 4 , b o t h b a s i n s w e r e v i s i t e d a n d e a c h was made w i t h lateral two p r o b e s i n a n e f f o r t recovery are l i s t e d here. one a) t o g a i n some i n f o r m a t i o n o n t h e extent of the microstructure patches. made; t h e i r p o s i t i o n , drop Nine double drops were time and separation of t h e probes a t launch and i n Table I . Only f i v e double p r o f i l e s These a r e Drop 6 t o Drop 10. are presented One STD l o n g - c h a n n e l s e c t i o n a n d c r o s s - c h a n n e l STD s e c t i o n a t Howe 4 w e r e t a k e n . Recent e v o l u t i o n o f w a t e r p r o p e r t i e s i n Howe S o u n d : F i g u r e 38 c o m p a r e s STD p r o f i l e s made J a n u a r y 2 2 , 1 9 7 4 a n d F e b r u a r y 4, 1974 ( t w o w e e k s a p a r t ) i n t h e O u t e r B a s i n a n d i n t h e I n n e r B a s i n a t Howe 4.5. F i g . 38 shows t h a t a s i g n i f i c a n t temperature d e c r e a s e h a s t a k e n p l a c e a b o v e 100 m i n t h e two w e e k s w h i c h preceded the February microstructure cruise. I n the Inner Basin, a temperature decrease has o c c u r r e d i n t h e upper Deep W a t e r , ature. t h e STD p r o f i l e s 60 t o 70 m. r e v e a l no s i g n i f i c a n t changes The d i s c u s s i o n p r e s e n t e d i n c h a p t e r I I about Water i n d i c a t e s similar In the i n temper- theIntermediate t h a t such a t e m p e r a t u r e change o c c u r r e d because t h e f o r m e r I n t e r m e d i a t e W a t e r h a s b e e n r e p l a c e d b y some new, c o l d e r It i s interesting at this point to mention g r a p h i c c r u i s e a l s o v i s i t e d Howe Sound o n M a r c h 1974). I t revealed t h a t no m a j o r s t r u c t u r e o f t h e w a t e r column cruse. b) t h a t an oceano- 1 5 , 1974 ( I . O . U . B . C , change i n t h e o v e r a l l temperature h a d o c c u r r e d s i n c e t h e F e b r u a r y 1974 I n t h e Deep W a t e r b e l o w 150 m, t h e l o w e s t t e m p e r a t u r e f r o m t h e h i g h e s t o n e b y 0.17 C ° . 1974 water differe T h i s c o m p a r e s t o 0.3 C° i n J a n u a r y a n d 0.5 C° i n November 1 9 7 3 . Temperature structure i n the Outer Basin: On F e b r u a r y 5, 1 9 7 4 , f o u r d o u b l e P u m p k i n d r o p s a n d f o u r STD c a s t s w e r e made i n R a m i l l i e s C h a n n e l (Outer B a s i n , f i g . l ) . o v e r a l l p r o f i l e o f Drop 6 has been p r o c e s s e d ( f i g . in fig. 29, l o c a t i o n 2 8 ) . The STD a n d P u m p k i n p r o f i l e s w e r e made s e v e r a l a p a r t and d i f f e r Only the o n l y a t s c a l e s o f 5 t o 10 m, n e a r t h e l i m i t shown hours of the s p a t i a l r e s o l u t i o n o f t h e STD. In files o r d e r t o make c o m p a r i s o n s e a s i e r , o f Drop 6 have been p u t back have been o f f s e t t o back. f r o m e a c h o t h e r b y 1.0 C ° . p r o f i l e accompanies the l e f t t h e rms g r a d i e n t p r o - The t e m p e r a t u r e The l e f t temperature p r o f i l e . profiles rms g r a d i e n t The Pumpkins were l a u n c h e d w i t h a s e p a r a t i o n o f 20 m. indicates Table I (discussed i n Chapter I I I ) that, d u r i n g the descent, the separation of the probes pro- b a b l y s t a y e d b e t w e e n 10 a n d 40 m. D r o p 6 ( f i g . 2 9 ) shows many a b r u p t t e m p e r a t u r e changes and l o c a l temperature i n v e r s i o n s w i t h r e s p e c t t o t h e main trend. were n o t v i s i b l e on t h e t e m p e r a t u r e p r o f i l e s probe. obtained with t h e STD C a r e f u l e x a m i n a t i o n o f t h e two t e m p e r a t u r e p r o f i l e s shows t h a t d i f f e r e n c e s b e t w e e n t h e two o c c u r e s s e n t i a l l y smaller than 2 m (the p r o f i l e s The profiles These o f Drop 6 at scales a r e made f r o m 0.4 m a v e r a g e s ) . o f t h e rms g r a d i e n t show t h a t m o s t o f t h e v a r i - a n c e a r i s e s f r o m a f e w p a t c h e s w i t h a t h i c k n e s s o f one t o t h r e e m e t r e s and w i t h i n t e n s i t i e s o f \ t o \\ C°/m ( r m s , u n c o r r e c t e d f o r t h e f r e - quency response o f t h e p r o b e s ) . A l a r g e p a t c h found i n one p r o f i l e may c o r r e s p o n d t o no p a t c h a t a l l i n t h e o t h e r p r o f i l e i n s t a n c e n e a r 105 m). A s i n t h e November 1973 d r o p s , r e g i o n s o f t h e p r o f i l e s w h e r e t h e t e m p e r a t u r e i s u n i f o r m show l i t t l e in the rest of the p r o f i l e s , the t h e r e i s no c l e a r r e l a t i o n s h i p including mean s q u a r e g r a d i e n t a v e r a g e d t h e upper aged o v e r b o t h p r o f i l e s over the whole 20 m) a n d t h e n e t t e m p e r a t u r e found a c r o s s i t a r e g i v e n i n Table I I I . between F i g u r e 29 shows c l e a r l y that this profile difference The mean s q u a r e g r a d i e n t a v e r - i s 26.5 x 10 ^ (C°/m)^. g r a d i e n t v a l u e o f p r o f i l e A i s about B. rms g r a d i e n t a n d , v a l u e o f t h e rms g r a d i e n t a n d t h a t o f t h e l o c a l mean g r a d i e n t . The (not (see f o r The mean square t w i c e as l a r g e as t h a t o f p r o f i l e i s due t o t h e o c c u r r e n c e o f d i f f e r e n t rms g r a d i e n t p a t c h e s i n e a c h p r o f i l e . I n each p r o f i l e , t h r e e o r f o u r p a t c h e s c a n a c c o u n t f o r more t h a n 9 0 % o f t h e g r a d i e n t c) variance. Temperature s t r u c t u r e i n t h e Inner B a s i n ' s I n t e r m e d i a t e Water: On F e b r u a r y 6, 1 9 7 4 , f o u r d o u b l e P u m p k i n d r o p s a n d a number o f STD p r o f i l e s w e r e made i n t h e I n n e r B a s i n o f Howe S o u n d . the p a r t of the p r o f i l e s which comes f r o m t h e I n t e r m e d i a t e W a t e r 100 m, s e e c h a p t e r I I ) i s e x a m i n e d . section d). Here, only (10 t o T h e Deep W a t e r i s r e s e r v e d f o r D r o p s 7 t o 10 a r e shown i n f i g . t i o n i n Howe Sound i s shown i n f i g . 2 8 . 30 t o 33 a n d t h e i r loca- One l o n g - c h a n n e l STD s e c t i o n and o n e c r o s s - c h a n n e l STD s e c t i o n a r e p r e s e n t e d i n f i g . 3 9 a n d 4 0 . All the temperature p r o f i l e s (STD a n d P u m p k i n s ) d i f f e r e a c h o t h e r m o s t l y i n t h e 30 t o 70 m r a n g e . ing to their from They c a n be grouped a c c o r d - resemblance. - D r o p 7 ( f i g . 3 0 ) a n d STD #7 ( f i g . 4 0 ) show a l a y e r o f r e l a t i v e l y u n i f o r m t e m p e r a t u r e b o u n d e d b y two s h a r p t e m p e r a t u r e s t e p s . fig.30, t h i s l a y e r has been l a b e l l e d " l a y e r B". In STD $7 was o b t a i n e d n e a r t h e S-E s i d e o f t h e c h a n n e l a t Howe 4 w h i l e D r o p 7 was a l s o o b t a i n e d a t Howe 4. - D r o p s 8 a n d 9 ( f i g . 3 1 a n d 32) a n d STD #6 a n d #8 ( f i g . 3 9 a n d 40) h a v e a p r o f i l e w h e r e t h e " l a y e r B" d o e s n o t show c l e a r l y . wise they a r e very s i m i l a r to the p r o f i l e s o f Drop Other- 7 a n d STD #7. They w e r e o b t a i n e d a t Howe 4, n e a r t h e c e n t e r o f t h e c h a n n e l . - D r o p 10 ( f i g . 3 3 ) a n d STD #5, #9, a n d #10 ( f i g . 3 9 a n d 40) h a v e i n common a t e m p e r a t u r e " b u l g e " l a b e l l e d o n D r o p 10 a s " l a y e r D". The h i g h e r r e s o l u t i o n of the Pumpkins shows t h a t the "bulge" c o n s i s t s of a temperature maximum f o l l o w e d about 10 m deeper by a minimum (Drop 10); these seem to be made of a number of s t e p s a few metres That type of s t r u c t u r e was the N-W s i d e of the The rms found a t Howe 4.7, Howe 4.5 and Howe 4 on channel. g r a d i e n t p r o f i l e s of Drops 7 to 10 (Inner B a s i n Intermediate Water) share many f e a t u r e s w i t h those of Drop 6 Basin). Most of the g r a d i e n t v a r i a n c e i s c o n c e n t r a t e d patches. uniform Maximum rms g r a d i e n t v a l u e s a r e 5 to 1 C°/m. temperature show l i t t l e rms gradient. s e v e r a l s t r i k i n g d i f f e r e n c e s between the rms Inner B a s i n and -The thick. (Outer in several Regions of However, t h e r e are a l s o g r a d i e n t p r o f i l e s of the the Outer B a s i n . rms g r a d i e n t patches are t h i n n e r and fewer i n Drops 7 to 9 than i n Drop 6. -The major rms g r a d i e n t patches are c l o s e l y a s s o c i a t e d w i t h the major temperature s t e p s (mostly i n Drops 7 and 8 ) . -Rms g r a d i e n t patches u s u a l l y correspond well. to patches found i n one p r o f i l e of a p a i r do i n the o t h e r p r o f i l e of the p a i r as T h i s i s t r u e even f o r minor patches -The i n Drops 7 to 9. temperature p r o f i l e s of Drops 7 to 9 c o n t a i n s m a l l e r and perhaps fewer temperature i n v e r s i o n s (with r e s p e c t to the main trend) than Drop 6. T a b l e I I I p r e s e n t s the temperature d i f f e r e n c e and square g r a d i e n t c a l c u l a t e d i n the Intermediate Water of each the mean drop. The average calculated f r o m D r o p s 7 t o 10 i s 8.6 x 10 h i g h e s t v a l u e and t h e second drop (Drop 8). (C°/m) . l o w e s t o n e a r e f o u n d i n t h e same The double The v a l u e s f o u n d i n t h e I n n e r B a s i n a r e t h u s 2 t o 4 t i m e s s m a l l e r t h a n t h o s e f o u n d i n t h e O u t e r B a s i n ( n o c o r r e c t i o n made in the frequency response). I n D r o p s 7, 8 a n d 9, t h e h i g h rms g r a d i e n t v a l u e s seem t o be closely related t o the temperature g r a d i e n t patches appear about to extend l a t e r a l l y 20 m s i n c e t h e y a r e u s u a l l y the temperature steps (fine structure). steps themselves. p i c t u r e i s more c o n f u s e d b e c a u s e The rms over d i s t a n c e s larger found on b o t h p r o f i l e s , j u s t than like I n D r o p 1 0 , f u r t h e r up i n l e t , t h e the temperature p r o f i l e s ous f i n e s t r u c t u r e l a y e r s accompanied r e v e a l numer- by g r a d i e n t v a r i a n c e . s u c c e s s f u l P u m p k i n d r o p was o b t a i n e d i n t h i s type of f i n e b u t t h e STD s e c t i o n s i n d i c a t e s t r u c t u r e might that such f i n e Only one structure have been found o v e r most o f t h e i n l e t . d) Temperature In this i s examined. s t r u c t u r e i n t h e I n n e r B a s i n ' s Deep W a t e r : s e c t i o n , t h e Deep W a t e r p a r t o f t h e P u m p k i n profiles The Deep W a t e r , a s d e f i n e d w i t h r e s p e c t t o t h e I n t e r m e d - i a t e Water i n chapter I I , i s found i n the Inner B a s i n below t h a t d e p t h , t h e STD p r o f i l e s s c a l e o f t h e Pumpkin show n o f i n e structure. has been expanded so t h a t s m a l l d i f f e r e n c e s become e a s i l y d e t e c t a b l e . The 100 m. At temperature temperature F i g . 3 4 t o 37 show t h e Deep W a t e r p a r t o f D r o p s 7 t o 10 w i t h a n e x p a n d e d s c a l e o f t e m p e r a t u r e . The rms g r a d i e n t s c a l e i s t h e same a s p r e v i o u s l y easier. t o make comparisons I n a l l t h e P u m p k i n p r o f i l e s , a s l i g h t t e m p e r a t u r e maximum is f o u n d n e a r 90 t o 95 m a n d a s l i g h t minimum i s f o u n d n e a r 105 t o 110 m. Drops 8 a n d 9 s t o p n e a r 125 m. minimum n e a r 125 m a n d a f t e r t o n i c a l l y w i t h depth u n t i l D r o p 10 shows a t e m p e r a t u r e t h i s , i t s t e m p e r a t u r e i n c r e a s e s mono- t h e e n d o f t h e d r o p , n e a r 170 m. 7, t h e Deep W a t e r t e m p e r a t u r e p r o f i l e i s v e r y s i m i l a r 1 0 , e x c e p t b e t w e e n 120 a n d 165 m. water w i t h I n Drop t o t h a t o f Drop T h e r e , D r o p 7 shows two l a y e r s o f t e m p e r a t u r e s 0.035 C ° w a r m e r t h a n t h o s e o f t h e w a t e r above o r below them a t s i m i l a r d e p t h i n D r o p 1 0 . Such found layered fine s t r u c t u r e w h e r e t h e w a t e r p r o p e r t i e s a l t e r n a t e b e t w e e n two t y p e s i s o f t e n d e s c r i b e d as " i n t e r l e a v i n g " , an e x p r e s s i o n which suggests that t h e r e a r e two d i s t i n c t b o d i e s o f w a t e r a n d t h a t t h e i n s t r u m e n t s w e n t through t h e i r i r r e g u l a r boundary. two w a t e r types i s n e g l i g i b l e ; The d e n s i t y d i f f e r e n c e b e t w e e n t h e the s a l i n i t y difference i s close to 0.006 °/oo. In t h e Deep W a t e r p a r t o f D r o p 7 ( f i g . 3 4 ) , g r a d i e n t v a l u e s a r e found only i n a s s o c i a t i o n w i t h ture. the layered struc- The t h i c k n e s s e s o f t h e p a t c h e s f o u n d b y t h e two p r o b e s d i f f e r by about 4 m. distributed in s i g n i f i c a n t rms W i t h i n t h e p a t c h e s , t h e rms g r a d i e n t i s d i f f e r e n t l y i n each p r o f i l e o f t h e p a i r . Differences are also t h e p r o f i l e s o f t e m p e r a t u r e a t s c a l e s o f up t o s e v e r a l found metres. I n D r o p 8 ( f i g . 3 5 ) , a p a t c h o f rms g r a d i e n t 5 t o 10 m was d e t e c t e d n e a r 100 m. was differently distributed. able fine On e a c h p r o f i l e o f t h e p a i r , The p a t c h was a c c o m p a n i e d s t r u c t u r e feature of the temperature p r o f i l e . thick t h e rms g r a d i e n t b y no remark- At similar d e p t h , n o n e o f t h e o t h e r P u m p k i n p r o f i l e s showed a n y s i g n i f i c a n t gradient variance. D r o p s 9 a n d 10 ( f i g . 3 6 a n d 37) showed no r e m a r k a b l e rms gradient IV.3 p a t c h e s i n t h e Deep W a t e r . Discussion. a) An I n t e r m e d i a t e Water c i r c u l a t i o n I n November 1 9 7 3 , and b o t t l e cast sections Howe 4.5, c r o s s - c h a n n e l channel ones. pattern? the cross-channel a n d l o n g - c h a n n e l STD showed t h a t b e t w e e n t h e s i l l and s t a t i o n t e m p e r a t u r e d i f f e r e n c e s were s i m i l a r New W a t e r was f o u n d m o s t l y o n t h e S-E s i d e o f t h e c h a n n e l and near t h e s i l l . I n F e b r u a r y 1974, i n t h e r a n g e o f 30 t o 70 m, d i f f e r e n c e s i n t h e a s p e c t o f t h e t e m p e r a t u r e p r o f i l e s ered i n a cross-channel s e c t i o n a t Howe 4 w e r e s i m i l a r encountered i n a long-channel s e c t i o n along Dahl phic subject was (1977) h a s o b s e r v e d a n a l o g o u s c o n t r a s t s i n Oslofjord. equilibrium with that currents within that f o r c e and t h a t the density fjord they appeared t o be i n g e o s t r o - field. Buckley (1977) a l s o mentioned f o r c e w o u l d e x p l a i n why t h e New W a t e r o f November 1 9 7 3 f o u n d m o s t l y o n t h e S-E s i d e o f t h e c h a n n e l s i n c e " r i g h t hand s i d e " f o r w a t e r e n t e r i n g Basin. t o those of the i n l e t . to Coriolis that C o r i o l i s encount- the center He i n t e r p r e t e d them a s a n i n d i c a t i o n are to long- the Inner Basin I n F e b r u a r y 1974, t h e c r o s s - c h a n n e l 4 may b e i n t e r p r e t e d i n t h e same f a s h i o n this i s the from the Outer d i f f e r e n c e s f o u n d a t Howe (fig.40). These interpretations pattern exist sill suggest t h a t a mean c o u n t e r - c l o c k w i s e circulation i n t h e I n t e r m e d i a t e Water o f t h e Inner B a s i n between t h e a n d Howe 4.5, a n d t h a t t h i s p a t t e r n may a c c o u n t oceanographic p r o p e r t i e s w h i c h w e r e shown t o o c c u r f o r changes i n on t i m e scales s h o r t e r t h a n one month ( c h a p t e r I I ) . b) The O s b o r n - C o x m o d e l : - O u t l i n e o f t h e Osborn-Cox model: The f i r s t e f f o r t f o rp u t t i n g temperature f o r m a t i o n t o use i n an oceanographic (1972). given. In this m o d e l i s due t o O s b o r n and Cox section, a very b r i e f account o f t h i s model w i l l be I t a p p l i e s t o r e g i o n s o f a w a t e r column where a steady g r a d i e n t i s found; of t h e February The Cox microstructure i n - (1972). F o u r i e r heat i n t h e Howe S o u n d d a t a , i t m i g h t a p p l y 1974 I n t e r m e d i a t e Water. The e s s e n c e o f t h e m o d e l c a n b e d e r i v e d s t a r t i n g diffusion equation e f o r an i n c o m p r e s s i b l e = the c o e f f i c i e n t of molecular ^v e (iv.i) 2 that radiative heat transfers are negligible. of variables: diffusivity. from the fluid: w h e r e D/Dt d e n o t e s t h e " m a t e r i a l d e r i v a t i v e " o p e r a t o r a n d expansion to regions complete d e r i v a t i o n o f t h e model i s g i v e n i n Osborn and ^ presents mean re- I t i s assumed N e x t , one uses t h e R e y n o l d s u. — 1 u. 1 1 + u! u. = E where space < scale. multiplies of > denotes 1 <u.> 1 (IV.2) < 6 > t h e a v e r a g i n g made o v e r some " s u i t a b l e " One e x p a n d s e q u a t i o n ( I V . 1 ) w i t h t h e R e y n o l d s i t b y Q' a n d t h e n p e r f o r m s t h e mean f i e l d i s assumed the averaging. variables, The d i v e r g e n c e t o be n e g l i g i b l e and t h e temperature f l u c t u a t i o n s a r e t a k e n t o be homogeneously d i s t r i b u t e d . then time and Equation (IV.1) becomes: 9_ < e^_2 3t 2 > = _ < . .e*> • 39 K < (V0*) > ~. 2 n U ; X (2) e q u a t i o n ( I V . 3 ) , term that molecular d i f f u s i o n always ance. - 3 . 1 (1) In f u (3) (3) i s always n e g a t i v e and i n d i c a t e s a c t s as a " s i n k " f o r temperature vari- Term ( 2 ) r e p r e s e n t s t h e i n t e r a c t i o n s b e t w e e n t h e v e l o c i t y fluc- t u a t i o n s and t h e t e m p e r a t u r e temperature v a r i a n c e . field and a c t s g e n e r a l l y as a " s o u r c e " o f T h e p r o d u c t <u^9'> c o r r e s p o n d s to a Reynolds f l u x of heat. F o r t h e Osborn-Cox m o d e l , one assumes a s t e a d y s t a t e and drops term field o r l a t e r a l eddy f l u x e s a r e n e g l i g i b l e , b u t t h a t v e r t i c a l are (1). significant. One t h e n a s s u m e s t h a t l a t e r a l g r a d i e n t s o f t h e mean E q u a t i o n (IV.3) then reduces t o : ones < or, after w'0' > =-X 30^ i s o l a t i n g t h e v e r t i c a l eddy < w'0' > < (ve ' )2 > (IV.4) flux: = ( V 0 ' ) 2 8 6 ( I V ' 5 ) 8Z Equation (IV.5) p r o v i d e s an a t t r a c t i v e method f o r e s t i m a t i n g v e r t i c a l heat t r a n s f e r s using temperature m i c r o s t r u c t u r e o b s e r v a t i o n s p r o v i d e d t h a t t h e r e g i o n o f t h e w a t e r column where i t i s a p p l i e d p e c t s t h e assumptions o f t h e model. a shape similar E q u a t i o n (IV.5) c a n a l s o be g i v e n to that of the heat d i f f u s i o n < » e» > w — res- K« problem: dv.6) || with: < (V0*) U and: 2 > ~ (IV.8) (3Z) In e q u a t i o n (IV.7) ^ f u s i o n and i s an "eddy c o e f f i c i e n t " P» i s c a l l e d of v e r t i c a l heat d i f - t h e C o x Number, a n o n - d i m e n s i o n a l r a t i o which h a s become w i d e l y a c c e p t e d f o r d e s c r i b i n g ture m i c r o s t r u c t u r e w i t h i n a monotonic -Cox n u m b e r s i n t h e F e b r u a r y 1974 In t h e F e b r u a r y 1974 the " i n t e n s i t y " of temperature tempera- profile. data: d a t a , t h e r e a r e two r e g i o n s o f t h e w a t e r column where t e m p e r a t u r e i n c r e a s e s m o n o t o n i c a l l y w i t h d e p t h . one i s f o u n d b e t w e e n 20 a n d 35 m i n D r o p s 7 t o 10 (fig.29 t o 33) it i s l a b e l l e d on D r o p 7 a n d D r o p 10 a s " l a y e r A". is a l s o f o u n d i n D r o p 7 t o D r o p 10 b e t w e e n 65 a n d 95 m a n d h a s labelled "layer In The The second first and region been C". l a y e r A, calculations derived directly t h a t t h e mean v e r t i c a l f r o m t h e d a t a show t e m p e r a t u r e g r a d i e n t i s , a b o u t 0.0135 C°/m and -3 the mean s q u a r e v e r t i c a l (C°/m) . 2 temperature gradient i s at l e a s t 9 x T h i s v a l u e does n o t t a k e i n t o account the l i m i t e d r e s o l u t i o n o f t h e p r o b e s and i n c l u d e any i n f o r m a t i o n about In spatial t h e Cox Number p r e s e n t e d h e r e d o e s n o t t h e h o r i z o n t a l component o f t h e ature gradient at microstructure G> > 10 scales. < (__£')• 2 ( 8 Z I t yields: > * ) (36) OZ) temper- 50 2 l a y e r C, d e t a i l e d p r o f i l e s p r e s e n t e d i n c h a p t e r V w i l l show t h a t most of t h e v e r t i c a l g r a d i e n t v a r i a n c e o c c u r s a t s c a l e s w h i c h can r e s o l v e d by the Pumpkins. Depending on how one chooses be the averaging 39 i n t e r v a l and w h i c h p r o f i l e one u s e s , one o b t a i n s C o x Number estimates of: 4 The to 25 q u e s t i o n a r i s e s - c a n t h e s e v a l u e s be i n t e r p r e t e d a s an eddy c o e f f i c i e n t o f v e r t i c a l d i f f u s i o n i n Howe S o u n d ' s Water? A number o f c o n s i d e r a t i o n s h a v e t o b e t a k e n -It Intermediate into account. i s n o t c l e a r t h a t t h e h o r i z o n t a l terms o f heat c a n b e n e g l e c t e d w i t h i n Howe S o u n d . transport S e c t i o n IV.3.a suggests t h e opposite. -It i s p o s s i b l e t h a t most o f t h e v e r t i c a l i s associated with processes going on n e a r t h e w a l l s o f t h e i n l e t o r i n conjunction w i t h strong weather events. Osborn-Cox model s t i l l cases, the processes i s taken into H e r e , i t was n o t . -The estimates I n these a p p l i e s on t h e c o n d i t i o n t h a t t h e temperature gradient v a r i a n c e a s s o c i a t e d w i t h these account. transport of heat limited s p a t i a l r e s o l u t i o n of t h e probes r e s u l t s i n o f t h e v e r t i c a l g r a d i e n t v a r i a n c e which a r e t o o low by an unknown f a c t o r . The h o r i z o n t a l component o f t h e g r a d i e n t variance are n o t observed. Layer C ( f i g . 30 a n d 33) p r e s e n t s that i t i s located mostly a shape r e m i n i s c e n t b e l o w maximum s i l l an i n t e r e s t i n g problem i n depth and i t s p r o f i l e has of p r o f i l e s found i n heat d i f f u s i o n problems. One w o u l d like t o v e r i f y i f an eddy d i f f u s i v i t y w i t h t h e C o x Number c o u l d b e c o m p a t i b l e w i t h coefficient derived the formation of l a y e r C by v e r t i c a l t u r b u l e n t t r a n s p o r t o r i f h o r i z o n t a l exchanges more l i k e l y mechanism. provide a On J a n u a r y 2 4 , 1 9 7 4 , STD p r o f i l e s showed t h a t t h e w a t e r c o l u m n b e t w e e n 50 a n d 100 m was n e a r l y i s o t h e r m a l ( f i g . 3 8 ) . t h e n assume t h a t b e t w e e n 60 a n d 90 m, t h e t e m p e r a t u r e was u n i f o r m and e q u a l t o t h e t e m p e r a t u r e o f t h e w a t e r and constant temperature source. where ^ e 2 I n t h i s problem, = 2 ^ 90 m, This prob- medium i n c o n t a c t w i t h a 70% o f t h e t e m p e r a t u r e change o c c u r s w i t h i n a d i s t a n c e H f r o m t h e s o u r c e such H initially found below t h a t i t h a s been r e d u c e d by v e r t i c a l eddy d i f f u s i o n . lem i s s i m i l a r t o t h a t o f a s e m i - i n f i n i t e L e t us that: t (IV.9) i s t h e eddy c o e f f i c i e n t o f v e r t i c a l h e a t d i f f u s i o n and t is the time elapsed since the constant temperature to the semi-infinite medium. s o u r c e was applied U s i n g e q u a t i o n s ( I V . 8 ) and ( I V . 7 ) , one o b t a i n s a C o x Number o f : § = H (IV.10) 2 I n l a y e r C, t h e v a l u e o f H on F e b r u a r y 6, 1974 i s a b o u t 30 m ( s e e D r o p s 7 t o 1 0 , f i g . 34 t o 3 7 ) . since the "constant temperature 1.2 x 1 0 ^ s e c ( t w o w e e k s ) . T h e maximum t i m e e l a p s e d s o u r c e " c o n d i t i o n was a p p l i e d i s a b o u t Using a molecular heat diffusion c o e f f i c i e n t o f 1.4 x 10 Number s h o u l d be a b o u t -7 2 m / s e c we 2600. find that the v a l u e of the Cox T h i s v a l u e i s at l e a s t a f a c t o r of 100 l a r g e r t h a n t h e v a l u e s r e p o r t e d e a r l i e r on t h e b a s i s o f t h e P u m p k i n data. One c o n c l u d e s t h a t l a y e r C was formed perhaps through inter- m i t t e n t " c a t a s t r o p h i c " m i x i n g e v e n t s w h i c h w e r e n o t o b s e r v e d o r , more likely, t h a t t h e shape o f the p r o f i l e of l a y e r C r e s u l t s from a d v e c t i o n of w a t e r coming the c) f r o m t h e O u t e r B a s i n and p r o f i l e does n o t r e s u l t t h a t t h e shape equation i t may Osborn-Cox model i s a p a r t i c u l a r (IV.3). Here, another p a r t i c u l a r be b e t t e r suited Sound's I n n e r B a s i n . fluid: case d e r i v e d f o r a d e s c r i p t i o n o f t h e Deep W a t e r o f Howe Take a volume o f f l u i d with i t s surroundings. whole volume, and (water) w h i c h has heat dropped i t becomes: < B 3t In this — - • -K < ( v e ' ) 2 «v.ii) > 2 case, 0 ( w h i c h does n o t appear e q u a t i o n ) i s t h e mean t e m p e r a t u r e w i t h i n temperature f i e l d <0' > 2 and explicitly t h e volume and s t a y c o n s t a n t s i n c e t h e r e a r e no h e a t e x c h a n g e s and i t s s u r r o u n d i n g s . the no an Then, i f a v e r a g i n g i s done o v e r t h e t h e t r a n s p o r t ' t e r m s o f e q u a t i o n ( I V . 3 ) c a n be _ to from case i s presented because i n h o m o g e n e o u s t e m p e r a t u r e d i s t r i b u t i o n and w h i c h u n d e r g o e s exchanges of from v e r t i c a l m i x i n g . A m o d e l f o r an i s o l a t e d and inhomogeneous v o l u m e o f The the i n the i t i s expected between the volume i s a measure of the inhomogeneity of i t i s e x p e c t e d t o d e c r e a s e w i t h t i m e due to the mixing can e f f e c t of m o l e c u l a r d e r i v e a time diffusion. From e q u a t i o n (IV.11), s c a l e which d e s c r i b e s the r a t e at which the a t u r e d i f f e r e n c e s w i t h i n the f l u i d are being d i s s i p a t e d by one temper- molecular processes: < e* 2 % In equation < 2 > (V0 ) 1 2 > ( STD probe. g r a d i e n t v a r i a n c e h o w e v e r i s a more d i f f i c u l t s p a t i a l r e s o l u t i o n has occur t o be i n t e r m i t t e n t l y and probes to sample (near case). V ' ( I V . 1 2 ) , t h e t e m p e r a t u r e v a r i a n c e i s an e a s y p a r a m e t e r measure, u s i n g f o r example a s t a n d a r d may I a t t a i n e d and full task since a very high s i n c e the g r a d i e n t t h e b o t t o m o r t h e s i d e s o f Howe S o u n d i n o b t a i n e d by a t t e m p t can still this t e m p e r a t u r e b e t w e e n November 1973 data. The significant and the data t h e P u m p k i n s i n t h e Deep W a t e r o f Howe S o u n d and Sound a p p e a r s t o h a v e u n d e r g o n e no the gradient. be made t o m a t c h some o f t h e i n f o r m a t i o n coming from oceanographic ) variance Moreover, f r e e - f a l l i n g m i c r o s t r u c t u r e probes measure o n l y An 2 to Measuring the at l o c a t i o n s which are dangerous f o r v e r t i c a l component of t h e t e m p e r a t u r e 1 January other Deep W a t e r o f Howe c h a n g e i n i t s mean 1974. During that period, b o t t l e c a s t m e a s u r e m e n t s showed t h a t t h e maximum t e m p e r a t u r e d i f f e r e n c e f o u n d w i t h i n t h e Deep W a t e r d e c r e a s e d suggests a mixing time f r o m 0.5 C° t o 0.17 C°. s c a l e of about t h r e e months ( t a k i n g f o r an e x p o n e n t i a l d e c a y ) and thus: T ^ 10^ sec This granted The maximum t e m p e r a t u r e d i f f e r e n c e i n F e b r u a r y 1974 was p r o b a b l y to 0.2 C° a n d t h i s suggests that: < 6' Equation > 2 0.01 ( C ° ) 2 (IV.10) t h e n r e q u i r e s t h a t on t h e a v e r a g e , t h e l e v e l o f gradient variance f o u n d i n t h e Deep W a t e r b e : < (V0') This value gradient signal. vable patches instruments). 2 > ^ 3 x 10" i s c l o s e t o t h e rms n o i s e (from s u c h a mean v a l u e should 3 (C°/m) 2 l e v e l o f t h e Pumpkin's H o w e v e r , due t o t h e p a t c h i n e s s ance d i s t r i b u t i o n , of the gradient give r i s e D r o p s 7 a n d 8 ( f i g . 3 0 a n d 3 1 , F e b r u a r y 1 9 7 4 ) show p a t c h e s 2 w i t h i n the patches. response of the probes would i n c r e a s e of a t Correcting f o r the t h i s value; averaging Deep W a t e r w a t e r c o l u m n w o u l d r e d u c e i t a l t h o u g h other frequency over the patches could e l s e w h e r e w i t h i n t h e Deep W a t e r . I n terms of o r d e r s observations in obser- the point of view of the s e n s i t i v i t y of the 10 t o 20 ( C ° / m ) well exist vari- to easily o f a b o u t 10 m t h i c k n e s s a n d w i t h mean s q u a r e g r a d i e n t v a l u e s least close o f m a g n i t u d e , i t seems t h a t t h e P u m p k i n show some c o n s i s t e n c y w i t h t h e b o t t l e c a s t t i m e s e r i e s t h e Deep W a t e r a s i n t e r p r e t e d i n t h e l i g h t o f e q u a t i o n (IV.12). What i s m i s s i n g now i s a m o r e c o m p l e t e c o v e r a g e o f t h e o c c u r r e n c e temperature gradient variance w i t h i n the Inner s p a t i a l r e s o l u t i o n f o r the probes. B a s i n and a higher of Chapter V V.l Introduction. T h i s chapter microstructure obtained as to p r e s e n t presents 21 d e t a i l e d p r o f i l e s o f temperature i n Howe Sound. They have been s e l e c t e d so s t r u c t u r e s which a r e t y p i c a l o f those d i f f e r e n t r e g i o n s of the water column p r e s e n t e d IV. found i n the i n chapters T i l and They a r e d i s c u s s e d i n terms of h o r i z o n t a l e x t e n t , relation- s h i p between f i n e s t r u c t u r e and m i c r o s t r u c t u r e , and p o s s i b l e causes f o r t h e i r existence. When two probes have been used s i m u l t a n e o u s l y , i n g p r o f i l e s a r e shown s i d e by s i d e . The u s u a l s i g n c o n v e n t i o n i s used to l a b e l the s c a l e of the v e r t i c a l temperature gradient ( p o s i t i v e g r a d i e n t when temperature i n c r e a s e s upwards). however t h a t , due to an i n c o n s i s t e n c y d u r i n g the data p o s i t i v e v a l u e s a r e p l o t t e d on the l e f t are l a b e l l e d accordingly. the r e s u l t - Notice processing, s i d e of zero g r a d i e n t and 45 V.2 Detailed A) profiles. November 1 9 7 3 p r o f i l e s : F i g u r e s 2 1 t o 24 show s e g m e n t s o f D r o p s 12 a n d 1 3 . d r o p s w e r e made a t s t a t i o n Howe 4 o n November 2 1 , 1 9 7 3 . p r o f i l e s o f D r o p 12 a n d 13 a r e p r e s e n t e d i n f i g . These The o v e r a l l 16 a n d 17 a n d t h e depths from w h i c h t h e d e t a i l e d p r o f i l e have been taken a r e i n d i c a t e d on them. In f i g . 21 ( f r o m D r o p P - 1 2 ) t h e t e m p e r a t u r e i n c r e a s e s down- w a r d s i n two " s t e p s " o f a b o u t 0.1 a n d 0.15 C ° . changes The t e m p e r a t u r e t a k e p l a c e o v e r v e r t i c a l d i s t a n c e s o f 0.2 t o 0.4 m. Between t h e two s t e p s , t e m p e r a t u r e f l u c t u a t i o n s w i t h a n rms a m p l i t u d e o f a b o u t 0.01 C° o c c u r a t s c a l e s s m a l l e r t h a n 0 . 1 m . scale temperature f l u c t u a t i o n s rather which give r i s e I t i s these than the temperature small "steps" to the f l u c t u a t i o n s of the temperature gradient. The g r a d i e n t f l u c t u a t i o n s f o r m a " p a t c h " w h i c h e x t e n d s f r o m one temperature step to the other. Within the "patch", the gradient r e a c h e s p e a k v a l u e s o f 2 C°/m o r m o r e . signal The p e a k s a r e a b o u t equally d i s t r i b u t e d between p o s i t i v e and n e g a t i v e v a l u e s . In fig.22 ( a l s o f r o m Drop P-12) t h e t e m p e r a t u r e w i t h i n c r e a s i n g depth i n an i r r e g u l a r fashion. d e c r e a s e , t h e r e i s a s m a l l t e m p e r a t u r e jump. the gradient variance i s associated w i t h scales smaller than 0.1m. decreases A t the bottom o f t h i s As i n f i g . 2 1 , most o f temperature f l u c t u a t i o n s a t I n t h e upper h a l f of fig.22, t h e peak v a l u e s o f t h e g r a d i e n t s i g n a l h a v e m o s t l y t h e same s i g n a s t h a t o f t h e mean g r a d i e n t . This p a r t o f f i g . 22 and i s i n c o n t r a s t w i t h what i s seen i n the through out f i g . 21. l o c a t e d n e a r t h e b o t t o m o f f i g . 22 little gradient Fig. s m a l l t e m p e r a t u r e jump i s associated with comparatively variance. 23 comes f r o m a r e g i o n o f D r o p 13 w h i c h p r e s e n t s abrupt temperature changes (see occurs The lower w i t h a 0.5 C°/m f i g . 17). h i g h , 0.12 N e a r 37 m, a 0.05 m thick gradient pulse. many C° N e a r 38 a t e m p e r a t u r e c h a n g e w i t h a s i m i l a r m a g n i t u d e i s a c c o m p a n i e d by c l u s t e r of g r a d i e n t smaller panied t h a n 0.05 by spikes peaking m. N e a r 38.7 a single gradient m a 0.06 most o f the g r a d i e n t peak v a l u e s Fig. (averaged 24 p r e s e n t s these small s c a l e s , there to the main t r e n d ) . s i g n as t h e mean g r a d i e n t . a b o u t 0.077 C°/m plotted here). over i n t e r v a l s while In these o f one r a m p s , e a c h a b o u t 1.5 a nearly isothermal respect with m C°/m examples, t h a t of o r two The temperature thick, a t s c a l e s o f 0.1 separated m thick. m or less. (with l a r g e g r a d i e n t peaks have the mean g r a d i e n t t h e r.m.s. g r a d i e n t r e s p o n s e o f t h e p r o b e s ) i s a b o u t 0.2 the metres). a r e many t e m p e r a t u r e i n v e r s i o n s A l l the a i s accom- l a y e r a l s o a b o u t 1.5 mainly C°/m, same t h r o u g h t h e ramps i s (uncorrected 2\ m, thicknesses temperature step h a v e t h e same s i g n as F l u c t u a t i o n s i n temperature occur At C° and a r e g i o n o f D r o p 13 w h e r e t h e d e c r e a s e s w i t h d e p t h i n two f r o m e a c h o t h e r by t o 2 C°/m s p i k e w h i c h p e a k s a t more t h a n 3 ( t h e maximum v a l u e w h i c h c o u l d b e l o c a l mean g r a d i e n t a t 1.5 change times f o r the limited larger. I n summary, t h e m i c r o s t r u c t u r e p r o f i l e s o f November show t h a t t h e a b r u p t t e m p e r a t u r e c h a n g e s w h i c h w e r e s e e n i n t h e 1973 overall profiles cases. t a k e p l a c e o v e r v e r t i c a l d i s t a n c e s o f 0.1 The temperature changes occur e i t h e r as r e g i o n s of l a r g e detailed in may temperature f l u c t u a t i o n s p r o f i l e i s s m o o t h and a l m o s t the temperature g r a d i e n t which be c a u s e d b y single m o s t l y t h e same s i g n , has peaks values. to ("ramps"). the The v a r i a n c e profiles of s p i k e s which have where the g r a d i e n t between p o s i t i v e and n e g a t i v e o f a t e m p e r a t u r e c h a n g e seems p o o r l y related of the g r a d i e n t v a r i a n c e t h a t goes w i t h i t , i f i t i s at a l l . Outer B a s i n , February detailed presented here. 1974. p r o f i l e s t a k e n from Drop 6 ( F e b r u a r y D r o p 6 was made i n R a m i l l i e s I t s o v e r a l l p r o f i l e i s p r e s e n t e d i n f i g . 29 detailed and Channel 1974) (Outer the l o c a t i o n of Basin). the p r o f i l e s i s shown on i t . Fig. 41 p r e s e n t s a l o c a l t e m p e r a t u r e maximum f o u n d n e a r d e p t h o f 57 m i n D r o p 6. A t t h e t o p o f t h e warmer l a y e r , t u r e c h a n g e t a k e s p l a c e t h r o u g h s t e p s o f 0.1 thick. o r as r e g i o n s where or patches of f l u c t u a t i o n s The m a g n i t u d e Three are spikes, a clustering i n many as a b r u p t jumps ( " s t e p s " ) , i s observed i n the o v e r a l l equally distributed the magnitude related B) about linear to 2 metres S t e p s were f o u n d by b o t h p r o b e s s t e p s d i f f e r on each p r o f i l e . translate into t o 0.2 C°/m, C ° , 0.2 tempera- t o 0.5 although the d e t a i l s of In the gradient s i g n a l , s p i k e s p e a k i n g a t more t h a n 3 C°/m a t more t h a n 4.5 the a m the the steps ( a n d i n some c a s e s the l i m i t of the d i g i t i z e r ) . In the signal, t h e s p i k e s a r e t h i n n e r t h a n 0.05 (fig. 2 9 ) , t h e s e few I n the o v e r a l l p r o f i l e o f Drop 6 spikes give rise gradient "patch" of t h i s At the bottom 60 m, m. t o one r.m.s. drop. o f t h e warmer l a y e r (between d e p t h s o f 59 where temperature d e c r e a s e s downwards), the temperature t a k e s t h e s h a p e o f a s m o o t h "ramp". The and profile gradient signal consists " r i p p l e s " w i t h a wave l e n g t h o f a b o u t 0.05 0.2 of the l a r g e s t m and an a m p l i t u d e o f of about C°/m. I n p r o f i l e B, on t h e r i g h t o f f i g u r e 4 1 , j u s t a b o v e the t e m p e r a t u r e "ramp", t h e r e i s a p a t c h o f h i g h wave number g r a d i e n t fluctuations. The g r a d i e n t peaks p o s i t i v e and n e g a t i v e v a l u e s . 0.4 C°/m ( u n c o r r e c t e d ) and are about e q u a l l y d i s t r i b u t e d The r.m.s. v a l u e o f t h e g r a d i e n t i s t h e p a t c h i s 0.75 s i g n a l i n t e g r a t e s i n t o a net temperature the patch. profile I t i s interesting to n o t i c e m thick. Yet the g r a d i e n t c h a n g e o f o n l y 0.02 t h a t no C° a c r o s s such p a t c h i s found i n A. F i g u r e 42 shows t h e d e t a i l o f a l a r g e m i c r o s t r u c t u r e found i n Drop 6 n e a r 70 m. t h e two p a t c h e s a r e o f f s e t temperature I n t h e o v e r a l l p r o f i l e o f Drop 6 i n d e p t h by about s t e p s have been r e a l i g n e d sons. At s c a l e s of 1 m or l e s s , little resemblance scales smaller The between to each o t h e r . t h a n 0.1 3 m. (fig.29), I n f i g u r e 42, i n order to f a c i l i t a t e t h e two patch compari- temperature p r o f i l e s More temperature the bear fluctuations at m are found i n p r o f i l e A than i n p r o f i l e B. amplitude of the temperature f l u c t u a t i o n s i s comparable temperature d i f f e r e n c e found a c r o s s the "patch". The to the gradient signal peaks a t v a l u e s l a r g e r t h a n 3 C /m, on b o t h s i g n s . The p a t c h o f p r o - f i l e A c o n t a i n s s e v e r a l t i m e s more g r a d i e n t v a r i a n c e t h a n t h a t o f profile B. In f i g u r e 43, the l a s t p a i r of d e t a i l e d p r o f i l e s t o be p r e s e n t e d i n D r o p 6, p r o f i l e A shows a l a r g e p a t c h o f g r a d i e n t f l u c t u a t i o n s which i s n o t f o u n d a t a l l i n p r o f i l e B. temperature p r o f i l e s are altogether d i f f e r e n t : t e m p e r a t u r e maximum w h i c h Moreover, p r o f i l e A presents a i s n o t f o u n d i n p r o f i l e B. w e r e s e p a r a t e d h o r i z o n t a l l y b y 10 t o 30 m a n d p r o b e B, slightly the slower than probe A d u r i n g t h i s p a t c h some 40 s e c o n d s later The two sinking A. temperature s t r u c t u r e s a,t s c a l e s o f 2 m o r l e s s o f t e n do n o t c o r r e s p o n d o n two p r o f i l e s pair. Here, the d e t a i l e d p r o f i l e s of a p r e s e n t i n s t a n c e s where t h e type o f m i c r o s t r u c t u r e i s t h e same o n b o t h p r o f i l e s upper probes drop, reached the depth of than probe I t was n o t e d i n C h a p t e r I V t h a t the ( f o r i n s t a n c e on t h e a n d l o w e r s i d e s o f t h e t e m p e r a t u r e maximum n e a r 55 m). In o t h e r i n s t a n c e s , t h e r e were l a r g e d i f f e r e n c e s i n t h e t y p e o f m i c r o s t r u c t u r e a s w e l l a s i n t h e amount o f g r a d i e n t v a r i a n c e o b s e r v e d , f o r i n s t a n c e , n e a r 58 m. N e a r 105 m, a large patch of gradient variance was f o u n d i n one p r o f i l e w h i l e n o n e was f o u n d i n t h e o t h e r . depth, s l i g h t types. d i f f e r e n c e s c o u l d a l s o be found i n the l o c a l At water that 50 C) F e b r u a r y 1974, Eleven Intermediate Basin). sets of d e t a i l e d p r o f i l e s obtained i a t e Water of the Inner Basin are presented s t r u c t u r e s f o u n d i n D r o p s 7, f r o m one Water (Inner profile 8 and to the next. here. i n the A v a r i e t y of 9 ( s t a t i o n Howe 4) D r o p 10 p r e s e n t s Intermed- c a n be a fine traced structure a m i c r o s t r u c t u r e w h i c h i s d i f f e r e n t enough from t h a t of the and other drops to deserve s p e c i a l a t t e n t i o n . Drop 7 I n the o v e r a l l p r o f i l e l o c a t e d b e t w e e n 10 and 40 m p r e s e n t s Y e t , when s m a l l p a t c h e s a r e pair. F i g u r e 44 these structures. perature 30 m). These a r e not i s a l s o of i n t e r e s t rise ature gradient as increases s m a l l as (see 0.2 and downwards 46 i n D r o p 7 n e a r 43 and m i n the for instance to the main trend) at I n p r o f i l e A, there tem- near of scales n o t i c e a b l e i n the o v e r a l l profiles. give temper- direction). show two 53 m the at to n o t i c e t h a t the g r a d i e n t peaks which ( i n the 45 of gives a closer look abrupt temperature changes (see o v e r a l l p r o f i l e ) . t h a t each probe sensed a d i f f e r e n t m i c r o s t r u c t u r e at the step. variance. to the v a r i a n c e patches are found where t h e r e are a b r u p t Figures occur region t o n o t i c e t h e p r e s e n c e o f a number temperature i n v e r s i o n s (with respect It the show on e a c h p r o f i l e s e e n on b o t h p r o f i l e s It i s interesting m. little t o 34 m and I t shows t h a t d e t a i l s c a n be s m a l l e r t h a n 0.5 very found, they comes from. 28 profile of Drop 7 ( f i g . 30), i s a patch of g r a d i e n t F i g . 45 that shows temperature spikes with mostly the s i g n as the mean g r a d i e n t . occurs it, through o n l y two In p r o f i l e B, the temperature change large gradient spikes. J u s t a few cm above however, t h e r e are g r a d i e n t f l u c t u a t i o n s about a zero mean. 4 6 m, t h e r e i s a temperature change w i t h no significant Near gradient variance. In f i g . 4 6 , the temperature steps of both probes are accompanied by a g r a d i e n t s i g n a l which c o n s i s t s of s e v e r a l s p i k e s magnitudes of more than 4 C°/m. w i t h i n 0 . 2 m. Below 5 4 m, monotonously downwards. No Most of the temperature change the temperature i n c r e a s e s i r r e g u l a r l y The g r a d i e n t s i g n a l p r e s e n t s no temperature i n v e r s i o n (with r e s p e c t to the main trend) even at the s m a l l e s t s c a l e s . i s - 0 . 0 . 4 4 C ° / m while Between 5 5 and 5 9 m, occurs but l a r g e peaks. i s observed the mean g r a d i e n t the r.m.s. g r a d i e n t i s about 0 . 0 9 C ° / m (a f a c t o r of t h r e e above the n o i s e level). F i g u r e s 4 4 , 4 5 and 4 6 are t y p i c a l of t h r e e r e g i o n s of Drop 7 which are o u t l i n e d i n the o v e r a l l p r o f i l e to f i g . 3 0 and " l a y e r A", with " l a y e r B" and " l a y e r C". called These r e g i o n s of the water column are examined a g a i n i n Drops 8 and 9 . Drop 8 Two (fig. one km 4 7 and detailed profiles 48). Drop 8 was taken from Drop 8 are p r e s e n t e d made one hour a f t e r Drop 7 and of the p o s i t i o n of Drop 7 . shares many f e a t u r e s w i t h The within o v e r a l l p r o f i l e of Drop 8 t h a t of Drop 7 . here Fig. changes 47 comes f r o m 19 t o 26 m. a r e s e e n on e a c h p r o f i l e (near Two main temperature 20 a n d 23.5 m). Near 20 m, small temperature i n v e r s i o n i s a l s o observed i n both p r o f i l e s . t h i s r e g i o n of the water Two temperature steps column, t h e mean g r a d i e n t a c c o u n t f o r one B e t w e e n t h e s t e p s , t h e mean g r a d i e n t third a n d a number o f m i n o r temperature steps this trend. temperature step, there pulse. below The A t each major pulses still a c c o u n t f o r much o f is a a g r a d i e n t p u l s e , t h e r e a r e a l s o some g r a d i e n t Fig. The t h a t w h i c h was gradient separated A t 24 f l u c t u a t i o n s which by a l o c a l I t presents t e m p e r a t u r e maximum a n d temperature l a y e r i n g of t h i s f i g u r e i s very found i n Drop 7 a t s i m i l a r depth two similar ( s e e f i g . 45 a n d What i s m i s s i n g h e r e i s a n e a r l y i s o t h e r m a l l a y e r w h i c h , i n D r o p was f o u n d b e t w e e n 47 a n d 52 m ( t h e t e m p e r a t u r e minimum). s p i k e s a r e f o u n d a s i n D r o p 7. o c c u r w i t h i n one m e t r e temperature step steps m i n D r o p 7. o f p r o f i l e B ( r i g h t hand s i d e ) c a n a l s o be f o u n d i n D r o p s steps. Notice 46). 7, changes that the consists i n fact Such " s p l i t t i n g " to Gradient H e r e , most o f t h e t e m p e r a t u r e i n s t e a d o f 0.2 two c l o s e l y s p a c e d b u t d i s t i n c t m, on b o t h t r a c e s . 48 comes f r o m b e t w e e n 50 a n d 58 m. l a r g e t e m p e r a t u r e changes a minimum. 0.001 a c c o u n t f o r most o f the g r a d i e n t v a r i a n c e . form a s o r t of low amplitude "patch" C°/m. this. s t a y s c l o s e t o 0.005 t o C°/m In i s a b o u t 0.01 t o one h a l f o f a of of temperature 6 a n d 7, i n a l e s s p r o n o u n c e d fashion. Drop 9. Drop 9 was Drops a l s o made at s t a t i o n Howe 4, i n the v i c i n i t y of 7 and 8 and one hour a f t e r Drop 8. presented i n f i g . 32. The o v e r a l l p r o f i l e i s Four d e t a i l e d p r o f i l e s taken from Drop 9 are presented here. F i g . 49 p r e s e n t s the d e t a i l e d p r o f i l e between 28 and 35 m, the same depth range as f i g . 44 from Drop 7. v a r i a n c e o c c u r s between 32.5 and 34 m, w i t h i n a l o c a l temperature m i n i - mum. At 32.5 m, t h e r e i s a 0.2 decreases downwards. ient pulse. m t h i c k r e g i o n where the temperature I t i s accompanied by o n l y a low amplitude g r a d - The most i n t e r e s t i n g a s p e c t of f i g . resemblance t h a t i t p r e s e n t s to f i g . changes A p a t c h of g r a d i e n t 49 i s the s t r i k i n g 44 of Drop 7. Most temperature of one f i g u r e can be p a i r e d w i t h s i m i l a r ones i n the o t h e r and the a b s o l u t e v a l u e s of the temperatures a r e v e r y c l o s e . This gives the i m p r e s s i o n t h a t the d e t a i l s of the temperature p r o f i l e s may extend much f a r t h e r than the s p a c i n g of the two probes i n a double p r o f i l e and much l o n g e r than s e v e r a l hours. F i g u r e s 50 and 51 come from a r e g i o n of the water where Drops column 7 and 8 p r e s e n t e d two l a r g e temperature changes s e p a r a t e d by a minor maximum and minimum. Drop 9 p r e s e n t s the same " f i n e s t r u c t u r e " but i n a d i s t o r t e d f a s h i o n . In f i g . 50, the upper s i d e of the temperature maximum c o n s i s t s of a "ramp" r a t h e r than a temperature step. The bottom of the temperature maximum i s v e r y smooth and the c o r r e s p o n d i n g g r a d i e n t s i g n a l has a unique a s p e c t . Most of the g r a d - i e n t v a r i a n c e i s a s s o c i a t e d w i t h the p a t c h l o c a t e d on the ramp where t h e mean t e m p e r a t u r e i n c r e a s e s w i t h F i g u r e 51 p r e s e n t s consists of a mixture Notice t h e second temperature step. o f ramp a n d s t e p was n o t c l e a r are presented profiles. t o 72 m. file. the processing of the data, s p i k e was r e a l o r s p u r i o u s (although t h e two t e m p e r a t u r e f r o m a common s o u r c e 52 p r e s e n t s A mean g r a d i e n t of spurious i s found. F i g . 52 shows t h e a s p e c t Notice Its effect the pro- of temperature exists but very the presence of a spurious i n the temperature p r o f i l e g i b l e b u t i t s e f f e c t on e s t i m a t e s been l a r g e i f i t h a d gone signal). p a r t o f f i g . 46 ( D r o p 7 ) . The r.m.s. m i c r o s t r u c t u r e w h e r e a s i g n i f i c a n t mean g r a d i e n t p o i n t n e a r 57.5 m. steps different o f a b o u t 0.02 C°/m e x i s t s a c r o s s i s a b o u t 0.05 C°/m. gradient variance data. a d e t a i l e d p r o f i l e from the depth range of I t compares t o t h e l o w e r gradient to a single s i d e by s i d e , they were sensed a t s l i g h t l y and c o u l d n o t a r i s e Fig. During a t f i r s t whether t h i s T r a c e B showed t h a t i t was r e a l 65 Here, i t s p i k e w h i c h a c c o u n t s f o r most o f t h e g r a d i e n t v a r i a n c e o f t h i s r e g i o n o f t h e w a t e r column. times on b o t h d e t a i l e d t h a t o n t r a c e A, t h e t e m p e r a t u r e s t e p g i v e s r i s e gradient it depth. of the gradient variance little data i s neglicould have unnoticed. D r o p 10 Figures 53 a n d 54 p r e s e n t ( s t a t i o n Howe 4.7 i n t h e I n n e r the t h e m i c r o s t r u c t u r e o f D r o p 10 Basin) b e t w e e n 29 a n d 54 m. Notice d e p t h s c a l e h a s b e e n c o m p r e s s e d b y a f a c t o r o f two c o m p a r e d that of previous detailed profiles. The p r o f i l e that with o f f i g . 54 f o l l o w s immediately by t h a t o f f i g . 53. The d e p t h l e v e l o f 42 m i s t h u s a l a y e r o f maximum t e m p e r a t u r e w h i c h i s a b o u t o n e m e t r e At like the top of f i g . 53, there temperature p r o f i l e i s a very occupied thick. smooth, l o g a r i t h m i c - a b o u t 3 m t h i c k ( b e t w e e n 29 a n d 32 m). It i s a c c o m p a n i e d b y no s i g n i f i c a n t g r a d i e n t m i c r o s t r u c t u r e e x c e p t f o r a broad, low amplitude "pulse". Sound m i c r o s t r u c t u r e d a t a . i s a unique occurrence B e t w e e n 32 a n d 36 m, t h e r e l a y e r w i t h a somewhat s i m i l a r microstructure. This i n t h e Howe i s another temperature p r o f i l e but a very Here, a comparatively different l a r g e amount o f g r a d i e n t a n c e o r i g i n a t e s i n f l u c t u a t i o n s a t s c a l e s s m a l l e r t h a n 0.1 m. v a r i a n c e has a d i f f e r e n t s p a t i a l d i s t r i b u t i o n w i t h i n each Through t h e l a y e r , t h e r e i s a l s o a s i g n i f i c a n t mean g r a d i e n t number o f m i n o r , h i g h wave number g r a d i e n t fig. 53 p r e s e n t mostly little gradient variance spikes. variThis profile. and a Other l a y e r s i n and t h e f l u c t u a t i o n s t a k e t h e s i g n o f t h e l o c a l mean g r a d i e n t . I n f i g . 54, o t h e r l a y e r s 1 t o 3 m t h i c k a r e a l s o found. o f them ( a t 45 a n d 5 1 m) a r e f a i r l y isothermal while sent s i g n a l c o n s i s t s mostly a mean g r a d i e n t . The g r a d i e n t w h i c h h a v e t h e s i g n o f t h e mean g r a d i e n t . spike i s considered t o be t h e r e s u l t of a spurious and data W a t e r o f D r o p 10 t h u s 8) w h i c h a r e a c c o m p a n i e d b y " o n e s i d e d " g r a d i e n t s m a l l e r t h a n 0.5 m i n t h e t e m p e r a t u r e p r o f i l e s gradient point. (compared t o those Most o f t h e l a y e r s a r e n o t even approximately pre- of spikes N e a r 49 m, a l a r g e The m i c r o s t r u c t u r e o f t h e I n t e r m e d i a t e c o n s i s t s o f rounded temperature steps the others Two of Drops 7 fluctuations. isothermal. Details are usually not identified i n b o t h p r o f i l e s a t once. found i n b o t h p r o f i l e s and i t i s c l e a r l a r g e r than about profiles 20 m l a t e r a l l y . indicate that The l a y e r s t h e m s e l v e s a r e a l w a y s that they extend over d i s t a n c e s A s was m e n t i o n e d t h i s s o r t o f s t r u c t u r e c o u l d have been found i n much o f t h e I n n e r B a s i n ' s I n t e r m e d i a t e W a t e r . o n l y one i n w h i c h i n C h a p t e r I V , STD H o w e v e r , D r o p 10 i s t h e t h e p r o b e s w o r k e d b e s i d e s t h e o t h e r d r o p s made a t s t a t i o n Howe 4 a n d i n t h e O u t e r Basin. Summary I n t h e I n t e r m e d i a t e W a t e r , D r o p s 7, 8 a n d 9 p r e s e n t a s i m i l a r f i n e and m i c r o s t r u c t u r e . Comparatively large temperature a r e f o u n d i n a l l t h r e e p r o f i l e s b e t w e e n 45 a n d 55 m. sequence of temperature a r e t h e same o n e s , v a r i e s b y s e v e r a l m e t r e s . have s i m i l a r v e r t i c a l and The v e r t i c a l l a y e r s between these s t e p s i s s i m i l a r three p r o f i l e s although the thickness of i n d i v i d u a l temperature sequences steps layers, i nthe i f they D r o p s 7, 8 a n d 9 a l s o i n t h e 15 t o 45 m range s u g g e s t t h a t s t r u c t u r e s 1 t o 3 m t h i c k may r e m a i n r e c o g n i z a b l e o v e r periods of at least s e v e r a l h o u r s a n d o v e r d i s t a n c e s much l o n g e r t h a n t h e n o m i n a l 20 m w h i c h s e p a r a t e ' t h e two p r o b e s i n any g i v e n p r o f i l e . Most o f t h e g r a d i e n t v a r i a n c e found i n t h e I n t e r m e d i a t e Water o f t h e I n n e r B a s i n i s a s s o c i a t e d w i t h nected minor to the large temperature the g r a d i e n t s p i k e s con- s t e p s f o u n d b e t w e e n 45 a n d 55 m. patches of gradient v a r i a n c e r e s u l t from s m a l l groups amplitude g r a d i e n t s p i k e s which occur near the minor Other of low temperature steps. These patches a r e u s u a l l y seen on both p r o f i l e s of a p a i r and seem to extend l a t e r a l l y f u r t h e r than the nominal 20 m probe s e p a r a t i o n . the temperature p r o f i l e s , d e t a i l s as t h i n as 0.2 m can be In identified at once on both p r o f i l e s of a p a i r . The f i n e s t r u c t u r e of Drop 10 d i f f e r s markedly from t h a t of Drops 7, 8 and 9. I t p r e s e n t s numerous l a y e r s and s e v e r a l maxima and minima. temperature Most l a y e r s a r e not i s o t h e r m a l and the temperature steps which s e p a r a t e them are rounded compared to those of the p r e c e d i n g drops. G r a d i e n t v a r i a n c e a r i s e s m o s t l y from "one s i d e d " g r a d i e n t f l u c t u a t i o n s , as i n the p r e v i o u s drops. D) Inner B a s i n Deep Water ( F e b r u a r y 1974). Three d e t a i l e d p r o f i l e s from the Deep Water a r e p r e s e n t e d here. The f i r s t two, f i g . 55 and 56, show a m i c r o s t r u c t u r e p a t c h found i n Drop 7 between 130 and 150 m. i n Drop 8 near 105 m. which was The depth s c a l e of the p r o f i l e s i s the same one used f o r Drop 10. Through f i g . 55 and 56, the temperature p r o f i l e s of b o t h probes p r e s e n t an "S" shape. file The o t h e r p r o f i l e shows a p a t c h found T h i s i s a l s o v i s i b l e i n the o v e r a l l p r o - of Drop 7 w i t h a m a g n i f i e d temperature s c a l e (fig. 34). The d e t a i l s of each p r o f i l e of the p a i r d i f f e r s i g n i f i c a n t l y at s c a l e s s m a l l e r than 3m. For i n s t a n c e , i n p r o f i l e B the downwards temperature i n c r e a s e takes p l a c e i n a-graded f a s h i o n over 2.5 m. In p r o f i l e A, the same temperature i n c r e a s e takes p l a c e i n one s i n g l e step where the g r a d i e n t p e a k s a t m o r e t h a n 4.5 C /m. The g r a d i e n t v a r i a n c e a t e d w i t h t h e s p i k e o f p r o f i l e A i s o f t h e same o r d e r the v a r i a n c e associated with the corresponding patch associ- of magnitude as i n p r o f i l e B. Many o t h e r d i f f e r e n c e s a r e a l s o f o u n d i n t h e t h i c k n e s s o f f e a t u r e s t h a t c a n be i d e n t i f i e d Fig. 100 on b o t h profiles. 57 shows a m i c r o s t r u c t u r e p a t c h w h i c h i s f o u n d b e t w e e n a n d 110 m i n D r o p 8, w i t h i n a s l i g h t overall p r o f i l e with a magnified t e m p e r a t u r e minimum ( s e e t h e t e m p e r a t u r e s c a l e o f f i g . 3 5 ) . The t e m p e r a t u r e d i f f e r e n c e s f o u n d h e r e a r e s m a l l compared t o what h a s been found i n other comparatively variance drops ( a b o u t 0.01 C ° h e r e ) . low values (typically The g r a d i e n t 1 C°/m). a l s o peaks a t Much o f t h e g r a d i e n t i s a s s o c i a t e d w i t h s c a l e s s m a l l e r t h a n 0.05 m a n d t h e g r a d i e n t peak v a l u e s are distributed about e q u a l l y between p o s i t i v e and n e g a t i v e values. Except f o r a few patches, presents very little t h e Deep W a t e r o f Howe S o u n d gradient variance. are present, t h e two p r o b e s g i v e p r o f i l e s s c a l e s lower than 2 or 3m. When t e m p e r a t u r e d i f f e r e n c e s that d i f f e r s i g n i f i c a n t l y at I t i s interesting t o n o t i c e t h a t between 80 a n d 110 m, t h e w a t e r c o l u m n s o f D r o p s 7 t o 10 h a v e s i m i l a r ture p r o f i l e s variance. b u t t h a t o n l y Drop 8 p r e s e n t s a large patch tempera- of gradient V.3 a) Discussion. Summary o f m i c r o s t r u c t u r e d e s c r i p t i o n : In the preceding used r e p e a t e d l y section, several expressions f o r d e s c r i b i n g f e a t u r e s o f t h e temperature f i n e and microstructure. Here, a list i s presented. As seen from s c a l e s o f 1 t o 5 m , p r o f i l e s were d e s c r i b e d across them. have been segments o f t h e t e m p e r a t u r e i n t e r m s o f t h e mean t e m p e r a t u r e gradient H e r e , "mean" o r " l o c a l mean" i n d i c a t e s t h a t a v e r a g i n g i s made o v e r t h a t s e g m e n t . T h u s t h e l o c a l mean g r a d i e n t may b e w i t h a temporary f e a t u r e o f t h e w a t e r column associated o r may h a v e a s i g n diffe- r e n t f r o m t h a t o f t h e " o v e r a l l mean g r a d i e n t " a v e r a g e d o v e r a l a r g e p o r t i o n of the water column. •As s e e n f r o m s c a l e s o f 0.5 t o 2 m , can be d e s c r i b e d "Temperature roughly temperature i n terms o f : s t e p s " when a t e m p e r a t u r e c h a n g e t a k e s v e r t i c a l distance smaller t h a n 0.5 m place over a ( i . e . i n f i g . 45 a n d 5 4 ) . "Temperature r a m p s " when a t e m p e r a t u r e c h a n g e t a k e s cal distance o f 1 m o r more i n a g r a d u a l "irregular microstructure fashion place over a v e r t i - (i.e. f i g . 41). t e m p e r a t u r e c h a n g e " when a t e m p e r a t u r e c h a n g e t a k i n g over v e r t i c a l distances l a r g e r than 1 m i s accompanied temperature f l u c t u a t i o n s a t smaller scales by l a r g e ( i . e . f i g . 22). place Much o f t h e t e m p e r a t u r e g r a d i e n t m i c r o s t r u c t u r e c a n b e described -Spikes i n terms o f : and p u l s e s as a r e seen, f o r i n s t a n c e , i n f i g . 41. -"one sided gradient patch of gradient s i g n a l " when m i c r o s t r u c t u r e c o n s i s t s o f a f l u c t u a t i o n s w h i c h peak m o s t l y w i t h one s i g n a s , f o r i n s t a n c e , i n f i g . 24. -"symmetrical present gradient f l u c t u a t i o n s " when t h e g r a d i e n t peaks t a k i n g both s i g n s w i t h about equal instance, V.3.b) fluctuations frequency as, f o r i n f i g . 21. R e l a t i o n s h i p s between t e m p e r a t u r e and t e m p e r a t u r e gradient microstructure: The gradient s i g n a l displayed i n the figures i s simply the d e r i v a t i v e of the temperature s i g n a l . questions is may b e a s k e d s u c h a s : Beyond t h i s r e l a t i o n s h i p , what type f o u n d t o accompany s u c h and s u c h a type structure or fine structure? Gargett of gradient microstructure of temperature micro- (1976) h a s a l s o sought such r e l a t i o n s h i p s a n d some o f h e r c o n c l u s i o n s a r e m e n t i o n e d b e l o w . are some o b s e r v a t i o n s sing upwards), temperature steps i s negative and g r a d i e n t (temperature spikes are often ( s e e f i g . 4 8 , 5 0 , 5 1 ) . When t h e l o c a l mean g r a d i e n t often l i t t l e Here w h i c h came f r o m e x a m i n i n g t h i s d a t a s e t . When t h e l o c a l mean g r a d i e n t is other gradient variance compared w i t h decreafound i s positive, that found i n there neighbouring (see regions f i g . 50 n e a r 46 of the w a t e r column. The profiles clear preference gradient (see t h i s type change ( f i g . 21, the with respect ( f i g . 42, 41, 43, 45) while i n other temperature gradient variance are t h a n c o u l d be recorded i t s amplitude thus i n d i c a t e t h a t the the w i d t h instances the patch type of where temperature constitutes temperature pro- by and temperature steps temperature d i f f e r e n c e alone. gradient pulses r e s o l v e and the probes as w e l l as with ( s e e f i g . 45 The the cannot There of amplitudes and 51). t h i n n e r i s the g r a d i e n t p u l s e , associated variance. For the observations s i z e of a t e m p e r a t u r e change does not of the g r a d i e n t pulses gradient However, i t i s o b s e r v e d t h a t amplitude temperature change, the l a r g e r are cases, "irregular" s p i k e s t h i n n e r t h a n what the p r o b e s can a given There are associated with the b a s i s of the i n s t a n c e s of wide, low higher 23). temperature are o f t e n a s s o c i a t e d w i t h s i n g l e s p i k e s o r a s m a l l g r o u p o f them. p r e d i c t e d on s i g n of the 56). Temperature steps be fluctuation i s found j u s t above o r u n d e r n e a t h a t e m p e r a t u r e change t h r o u g h an file to the f o r i n s t a n c e f i g . 21 and of patch smoother m). "Symmetric" patches of s m a l l s c a l e g r a d i e n t show no look that are associated w i t h i t . determine V.3.c) L a t e r a l extent - G i v e n two two of probes separated the smallest a t once? This of m i c r o s t r u c t u r e temperature p r o f i l e s obtained simultaneously by what i s the something l i k e s t r u c t u r e s which can d i s c u s s i o n b e a r s on t h e n w e r e d o u b l e p r o f i l e s made. probes' lateral i n Howe S o u n d . 10 be o r 20 m, i d e n t i f i e d on b o t h t h e F e b r u a r y 1974 See chapter data m of the Inner Basin (February ( f i g . 44 t o 54) show t h a t t h e p r o f i l e s at scales smaller t h a n 0.1 t o 0.3 m. since only the t o 0.3 m c a n be of p a i r s w i t h enough c o n s i s t e n c y they are p a r t of the i s to state that differ i n p a i r s of p r o f i l e s . identified Features on that thinner A n o t h e r way (by v i s u a l e x a m i n a t i o n ) i f t h e s e to prof- i l e s were low-passed f i l t e r e d w i t h a c u t - o f f a t 0.3 p a i r would look almost i d e n t i c a l . Note however t h a t c r o s s - s p e c t r a l a n a l y s i s might not agree w i t h limiting factor i n estimating N e a r 50 m, similarity Water of D r o p s 7, seems t o s t o p the f o r matching. Inner Basin, F i g . 55 the or s l i g h t l y a fea- different relative r e l a t i v e d i s p l a c e m e n t s c o u l d be a s p e c t r a l coherences. 8 and 9 present at scales smaller temperature steps t h a n 0.5 few m i c r o s t r u c t u r e t o 57 p r o f i l e s of t h i s r e s u l t because i d e n t i f i a b l e t u r e s o f t e n have d i f f e r e n t t h i c k n e s s p o s i t i o n i n the water column; m, mostly tempera- t o c o n v i n c e one same w a t e r " l e n s e s " o r l a y e r s . m definitely differ 1974), In other words, minor t u r e m a x i m a o r m i n i m a t h i c k e r t h a n 0.1 look at t h i s profiles I I I f o r d i s c u s s i o n of detailed profiles t h a n 0.1 size separation. I n t h e u p p e r 100 both p r o f i l e s by m. In the where Deep features are a v a i l a b l e show t h a t s c a l e s s m a l l e r than 1 to 3 m are u s u a l l y d i f f e r e n t i n two p r o f i l e s o f a p a i r . Throughout t h e O u t e r B a s i n ' s D r o p 6, s i m i l a r i t y b e t w e e n t h e p r o f i l e s s c a l e s s m a l l e r t h a n 1 o r 2 m i n most c a s e s (fig. i s small at 41 t o 4 3 ) . - G i v e n a t e m p e r a t u r e change w h i c h i s sampled b y two n e i g h - b o u r i n g p r o b e s , i s t h e same tijpz. o f m i c r o s t r u c t u r e o b s e r v e d b y b o t h ? T h r o u g h o u t t h e Howe Sound o b s e r v a t i o n s , when o n e t e m p e r a t u r e p r o f i l e was s t e p p y , t h e o t h e r o n e u s u a l l y was a l s o . When o n e p r o f i l e p r e s e n t e d h i g h a m p l i t u d e g r a d i e n t s p i k e s , so d i d t h e o t h e r one. a p p l i e s a l s o f o r t e m p e r a t u r e "ramps". This H o w e v e r , when a p a t c h o f "symmetrical g r a d i e n t f l u c t u a t i o n s " w i t h g r a d i e n t v a r i a n c e concentrated at scales smaller other p r o f i l e t h a n 0.05 m was f o u n d i n o n e p r o f i l e , t h e seldom p r e s e n t e d a p a t c h w i t h s i m i l a r examples o f t h i s were found i n Drop 6 ( f i g . (fig. 41 t o 4 3 ) . Many I n Drop 8 5 7 ) , a 10 m t h i c k p a t c h o f g r a d i e n t v a r i a n c e i s f o u n d b y b o t h probes b u t the g r a d i e n t v a r i a n c e i s d i s t r i b u t e d each extent. differently within profile. These o b s e r v a t i o n s i n d i c a t e t h a t p a t c h e s o f temperature m i c r o s t r u c t u r e o f t h e " s y m m e t r i c a l " , s m a l l s c a l e t y p e do n o t e x t e n d laterally o v e r d i s t a n c e s a s l a r g e a s 20 m i n t h e O u t e r B a s i n ( a n d s e l - dom o c c u r i n t h e I n n e r B a s i n i n F e b r u a r y 1 9 7 4 ) . types o f m i c r o s t r u c t u r e appear l a r g e r t h a n t h e 20 o r s o m e t r e s probes. Other t o extend l a t e r a l l y which identified over d i s t a n c e s separated the f r e e - f a l l i n g V.3.d) Turbulent o r not? There a r e patches o f temperature m i c r o s t r u c t u r e which, intui- t i v e l y , h a v e seemed t o b e " t u r b u l e n t " t o p e o p l e who h a v e s t u d i e d t h e detailed profiles. The one m e t r e t h i c k p a t c h a t 58 m i s o n e e x a m p l e o f t h i s . f o u n d i n D r o p 6 ( f i g . 41) There a r e a l s o other water column w h i c h , i n t u i t i v e l y s t i l l , regions of the seem n o t t o b e t u r b u l e n t . The l o w e r s i d e o f a t e m p e r a t u r e maximum f o u n d i n D r o p 9 ( f i g . 52) i s o n e such example. Y e t , between extreme cases l i e s t h e m a j o r i t y structure features. be one considered misleading? t o assess t h e purpose of t h i s is restricted and When t h i s occurs, density scales at least. to present eous p r o f i l e alone of a turbulence One t h e n e x p e c t s a n i n s t a n t a n e o u s preference structure described "symmetrical" earlier gradient fluctu- e x c h a n g e s o f f l u i d must t a k e s t r a t i f i c a t i o n must be " t u r n e d a disordered allow flow? d i s c u s s i o n , t h e meaning of vertical of the v e r t i c a l w h i c h show l i t t l e turbulent nature "intuition" t o random, s m a l l s c a l e , q u a s i - i s o t r o p i c v e l o c i t y the l o c a l ature or should Can t e m p e r a t u r e m i c r o s t r u c t u r e the turbulent or non-turbulent For ations. I s such an assessment v a l i d of micro- over" profile place at small o f temper- a s p e c t a t s m a l l s c a l e s and an i n s t a n t a n gradient should present fluctuations f o r one s i g n o r t h e o t h e r . as " i r r e g u l a r gradient" Thus,micro- and s m a l l f l u c t u a t i o n s a r e t h e most c o n s i s t e n t scale with stirring. Irregular temperature p r o f i l e s and " s y m m e t r i c a l " small scale gradient f l u c t u a t i o n s do n o t n e c e s s a r i l y mean t h a t t h e f l u i d which i s being sampled i s i n t u r b u l e n t m o t i o n . One c a n t h i n k o f counter examples. Take t h e case o f a b r i e f v i n g water s t r a t i f i e d turbulent episode i n d e n s i t y and t e m p e r a t u r e . Once invol- three- d i m e n s i o n a l t u r b u l e n c e s u b s i d e s , t h e p a r t i a l l y mixed volume o f water reorganizes i t s e l f a c c o r d i n g t o i t s new d e n s i t y structure. heat and s a l t have d i f f u s e d a t d i f f e r e n t m o l e c u l a r r a t e s , i n g s t a b l e water column w i l l profile with small scale tions of both signs. isotropic p r e s e n t an " i r r e g u l a r " Because the r e s u l t - temperature t e m p e r a t u r e i n v e r s i o n s and g r a d i e n t Y e t , i t i s n o more t u r b u l e n t fluctua- i n the semi- sense. M o l e c u l a r heat d i f f u s i o n a c t s towards d i s s i p a t i n g scale temperature gradient variance.. small The p r e s e n c e o f h i g h wave number gradient v a r i a n c e i n m i c r o s t r u c t u r e i s thus taken to suggest r e c e n t " a c t i v i t y " has t a k e n p l a c e o r i s g o i n g on. shown t h a t t e m p e r a t u r e g r a d i e n t v a r i a n c e r e s u l t s E c k a r t (1948) h a s from the d e f o r m a t i o n of t h e temperature f i e l d by t h e r a t e o f s t r a i n o f t h e f l u i d ' s Due t o t h e r m a l d i f f u s i v i t y , an i n f i n i t e l y sharp s t e p w o u l d t a k e 180 s e c t o t h i c k e n t o 0.01 m i n w a t e r 1972). Dimensional considerations involving and the thermal d i f f u s i v i t y ous temperature f i e l d , that motion. temperature (Osborn and Cox, a constant rate of s t r a i n of water i n d i c a t e that, i n an inhomogene- temperature gradient variance a t scales of the o r d e r o f 0.01 m c a n b e s u s t a i n e d b y a r a t e o f s t r a i n o f ( 1 8 0 s e c ) ^ o r 0.005 (m s e c "S m sufficient T h u s , c o m p a r a t i v e l y weak s h e a r s a r e t o cause g r a d i e n t v a r i a n c e a t s c a l e s s m a l l e r than those r e s o l v e d by t h e i n s t r u m e n t s , w i t h o u t r e c o u r s e t o t u r b u l e n t p r o c e s s e s . O s b o r n ( p e r s o n a l c o m m u n i c a t i o n ) h a s made o b s e r v a t i o n s o f b o t h t e m p e r a t u r e and v e l o c i t y m i c r o s t r u c t u r e . patches of both u s u a l l y occur together. He h a s found I n s e v e r a l i n s t a n c e s , he o b s e r v e d m i c r o s t r u c t u r e s h e a r v a r i a n c e w h e r e no o r l i t t l e g r a d i e n t v a r i a n c e was found. patches of v e l o c i t y ( a n d e v e n t u a l l y t u r b u l e n t m o t i o n ) may temperature On micro- go u n d e t e c t e d by the b a s i s of the p r e c e d i n g d i s c u s s i o n , a t t e m p t i n g to T u r b u l e n c e may temperature sensors i s r i s k y , go u n n o t i c e d o r e l s e m i c r o s t r u c t u r e may be n o n - t u r b u l e n t ( i n t h e s e m i - i s o t r o p i c s e n s e ) . are most c o n s i s t e n t w i t h t u r b u l e n c e a r e t h o s e w h i c h p r o f i l e suggesting a l o c a l density overturn. i n s t a n c e , i n f i g . 41 t o 43 a n d 57. patches Features which present "symmetrical" gradient fluctuations at small scales with a for i s homo- s e n s o r s when t h e t e m p e r a t u r e d i s t r i b u t i o n i s h o m o g e n e o u s . assess the occurrence of t u r b u l e n c e w i t h at best. has temperature T h i s o c c u r s where temperature g e n e o u s and b r i n g s up one m o r e p o i n t : structure that temperature Such f e a t u r e s a r e They a r e c a l l e d found, here "turbulent-like". On the b a s i s of the preceding d i s c u s s i o n , t h e r e are features which are c l e a r l y non-turbulent. of the water T h i s i s the case of r e g i o n s column w h i c h p r e s e n t a monotonous t e m p e r a t u r e s u c h a s f i g . 52 (Drop t h o s e f o u n d i n f i g . 24 8 n e a r 60 m). a n d f i g . 41 i n v e r s i o n s i n t h e mean t r e n d . ' In temperature ( n e a r 59 m), profile "ramps" such there are very In view of the r e g u l a r s t r u c t u r e s e n t e d by t h e p r o f i l e s , t u r b u l e n t s t i r r i n g explanation'(at least also seems t o be a n a t t h e t i m e when t h a t f e a t u r e was as small pre- unlikely sampled). I n Drop 6 is associated with thicknesses o f one sub-section, In the half variance t o two Water of variance which are not and ous the turbulent-like. c l u s t e r s o f "one others are not conclusion f i g . 21 to 24), Inner Basin, can due be butions t e m p e r a t u r e and to the possibility of the t o 100 some f e a t u r e s m) most drawn. m. of features are t o the p a u c i t y of d a t a and accom- these m. turbulentfrom I n t h e November 1973 found. this profiles The numer- found occur at s c a l e s of i m processes such or as overturn. not? Doubly-diffusive convection i d e a o f i t was preceding f o r more t h a n a b o u t 20 o c c u r r e n c e s of a l l types are Doubly-diffusive or When t h e (10 seem t o r e s u l t more f r o m a d v e c t i v e ever s i n c e the shown i n t h e f o r l e s s t h a n a b o u t 20 " i n t e r l e a v i n g " r a t h e r than from t u r b u l e n t V.3.e) patches have sided" gradient microstructure but variance They c o n s i s t of t e m p e r a t u r e s t e p s temperature i n v e r s i o n s which are l a r g e r and as Inner Basin p a t c h e s seem t o e x t e n d l a t e r a l l y r e g i o n , no (see m e t r e s and, The i s associated with microstructure I n t h e Deep W a t e r o f t h e like the gradient a turbulent-like microstructure. Intermediate by 1 9 7 4 ) , most of t h e y seem t o e x t e n d l a t e r a l l y the gradient panied (Outer B a s i n , has fascinated o u t l i n e d and salinity density gradient gradients tried oceanographers i n laboratory provide opposite tanks. contri- of a s t a b l e water column, t h e r e t h a t l o c a l d e n s i t y i n s t a b i l i t i e s d e v e l o p and l a r g e d i f f e r e n c e between the m o l e c u l a r is a grow b e c a u s e d i f f u s i o n rates of heat and salt. The r e a d e r i s r e f e r r e d t o Turner c u s s i o n o f work c a r r i e d on t h i s (1973) f o r a d e t a i l e d d i s - topic before 1973 and t o M o n i n e t a l . (1974) f o r an o v e r v i e w o f work c a r r i e d on b e f o r e 1972. Presumption of d o u b l y - d i f f u s i v e convection u s u a l l y based on v e r t i c a l p r o f i l e s present i n t h e ocean i s o f temperature and s a l i n i t y r e g u l a r l y s p a c e d l a y e r s o f homogeneous p r o p e r t i e s s e p a r a t e d sharp property changes o f t e n c a l l e d to begin w i t h , the property doubly-diffusive values consistent increases w i t h depth. Since increase w i t h depth a t l e a s t here, only the temperature gradient i s Over most o f t h e w a t e r column, doubly-diffusive instability temperature t h e w a t e r column i s s t a b l e , s a l i n i t y i n a compensating f a s h i o n . gradients are then c o n s i s t e n t w i t h t h e development of a of the " d i f f u s i v e type" a r e n o t f o u n d i n t h e Howe Sound p r o f i l e s . (see Turner, gradient variance Gargett temperature gradients. associated with negative diffe- with Moreover, the temperature gradients i s than that associated with p o s i t i v e temperature gradients. (1976) a l s o o b s e r v e d t h i s r e l a t i o n s h i p between t h e i n t e n s i t y of g r a d i e n t v a r i a n c e Cox vertical t o be a s s o c i a t e d 1973). elsewhere What i s f o u n d i s t h a t of temperature m i c r o s t r u c t u r e tend p o s i t i v e and n e g a t i v e must The o v e r a l l However, t h e l a r g e and r e g u l a r s t e p s w h i c h h a v e b e e n o b s e r v e d rent types with convection. known w i t h some p r e c i s i o n . property by i n t e r f a c e s , i n w a t e r columns where, gradients present In the data presented larger which and t h e f i n e (1972) a l s o o b s e r v e d temperature l o c a l l y s t r u c t u r e g r a d i e n t w h i l e Gregg and the steppy c h a r a c t e r o f m i c r o s t r u c t u r e when i n c r e a s e s downwards. These authors agree that doubly-diffusive convection i s very l i k e l y microstructure. to play a role i n shaping Gregg and Cox (1972) d i s c u s s t h i s i n more d e t a i l and show t h a t S o r e t d i f f u s i o n c o u l d a l s o be r e l e v a n t . However, on t h e b a s i s o f t h e i r d a t a and on t h e s t a t e o f knowledge, these c o u l d n o t come t o a c o n c l u s i o n a b o u t t h e i m p o r t a n c e d i f f u s i v e processes i n oceanic environments. authors of doubly- The same a p p l i e s here. Chapter VI Conclusion Howe S o u n d ' s w a t e r i s shown t o p r e s e n t The Surface Layer occupies t h r e e water masses. t h e u p p e r 10 m a n d e v o l v e s under t h e i n f l u e n c e o f f r e s h water r u n o f f , t i d e s and m e t e o r o l o g i c a l The Intermediate Strait The Outer Basin Inner 100 Water i s c h a r a c t e r i z e d by i t s exchanges w i t h t h e of Georgia. Intermediate Basin. m. F l u s h i n g time c a n be as s h o r t as a few weeks. Water i s c o n s i d e r e d t o occupy t h e whole o f t h e ( b e l o w 10 m) a n d t h e d e p t h r a n g e o f 10 t o 100 m i n t h e T h e Deep W a t e r o c c u p i e s I t stays trapped for periods t h e Inner Howe S o u n d r e v e a l e d types to c r u i s e s w h i c h w e r e made i n 9^ occurs t u r b u l e n t - l i k e m i c r o s t r u c t u r e p a t c h e s 0.5 t o 3 m f o r l e s s t h a n 20 m. the g r a d i e n t v a r i a n c e Intermediate I n t h e Inner i nassociation t h i c k w h i c h seem B a s i n , most o f i sassociated with microstructure features appear t o be n o n - t u r b u l e n t Basin's location, I n t h e O u t e r B a s i n , most o f temperature gradient variance extend l a t e r a l l y below of microstructure which v a r i e d with depth and temperature f i n e s t r u c t u r e . with Basin only, o f months t o y e a r s . Two t e m p e r a t u r e m i c r o s t r u c t u r e the v e r t i c a l effects. a t the time of sampling. Water, t h e l a t e r a l extent which I n the Inner of the gradient variance p a t c h e s a s w e l l a s t h a t o f i n d i v i d u a l f e a t u r e s a s t h i n a s 0.2 m, seems t o b e l a r g e r t h a n 20 m l a t e r a l l y . I n t h e Deep W a t e r , f e w m i c r o s t r u c t u r e features are detected. 2 m seem t o e x t e n d When t h e y a r e , o n l y s c a l e s l a r g e r t h a n f o r more t h a n a b o u t 20 m laterally. Regions o f t h e w a t e r column where t h e t e m p e r a t u r e ( a t s c a l e s o f 0.5 t o 2m) i s p o s i t i v e present (temperature gradient decreasing l e s s g r a d i e n t v a r i a n c e and smoother t e m p e r a t u r e R e g i o n s where t h e t e m p e r a t u r e g r a d i e n t i s n e g a t i v e downwards) profiles. often present t e m p e r a t u r e p r o f i l e s and t h e g r a d i e n t peaks a t c o m p a r a t i v e l y T h e s e comments a p p l y 1 or steppy high values. t o m i c r o s t r u c t u r e w h i c h was n o t t u r b u l e n t - l i k e . In t h e November 1973 d a t a , m i c r o s t r u c t u r e p a t c h e s w h i c h c o u l d b e d e s c r i b e d as t u r b u l e n t - l i k e occur both e q u a l l y w e l l w i t h i n r e g i o n s o f mean g r a d i e n t o f signs. The light r o l e o f temperature m i c r o s t r u c t u r e i s examined i n t h e o f t h e Osborn-Cox model and o f another developed i n this thesis. part of the Inner Basin's model f o rm i x i n g which i s The Oxborn-Cox model i s a p p l i e d t o t h e l o w e r Intermediate Water. I t suggests that turbulent d i f f u s i o n plays only a minor r o l e i n the Intermediate vertical Water n e a r 75 m, c o m p a r e d t o l a t e r a l a d v e c t i v e e x c h a n g e s b e t w e e n t h e I n n e r B a s i n and t h e o u t s i d e . important The m i x i n g model developed p a r a m e t e r s t h e t e m p e r a t u r e v a r i a n c e w i t h i n t h e Deep W a t e r , t h e mean s q u a r e t e m p e r a t u r e g r a d i e n t , m o l e c u l a r time scale f o r the mixing a t h r e e month time o f t h e Deep W a t e r . scale f o r mixing v a r i a n c e data a r e scant b u t they compatible scale. here r e t a i n s as h e a t d i f f u s i o n and a B o t t l e cast data t h e Deep W a t e r . a r e o f an o r d e r Deep W a t e r suggested gradient of magnitude which i s w i t h t h a t p r e d i c t e d by t h e model f o r t h e t h r e e month The r e s u l t s suggest time by t h e models a r e l i m i t e d by t h e a b i l i t y of the probes t o r e s o l v e t h e f u l l spectrum of temperature gradient ance and by t h e p o s s i b l e i n t e r m i t t e n c y o f m i c r o s t r u c t u r e p r o d u c i n g varievents. References B E L L , W i l l i a m H. 1 9 7 3 . The E x c h a n g e o f Deep W a t e r i n Howe Sound B a s i n . Pacific M a r i n e S c i e n c e D i r e c t o r a t e R e p o r t 73-13, Environment C a n a d a , V i c t o r i a , B.C. B E L L , W i l l i a m H. 1 9 7 5 . The Howe S o u n d C u r r e n t M e t e r i n g P r o g r a m , V o l u m e I I I , P a r t I - D a t a R e p o r t , S t a t i o n HS-5. P a c i f i c M a r i n e S c i e n c e R e p o r t 75-7. I n s t i t u t e o f Ocean S c i e n c e , P a t r i c i a B a y , V i c t o r i a , B.C. BUCKLEY, J o s e p h R. 1977. C u r r e n t s , w i n d s a n d t i d e s i n Howe S o u n d . Ph.D. T h e s i s , U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. p p . 228. Canadian H y d r o g r a p h i c S e r v i c e . 1977. C a n a d i a n T i d e a n d C u r r e n t T a b l e s , V o l . 5, J u a n de F u c a and S t r a i t o f G e o r g i a . C a n a d i a n H y d r o g r a p h i c S e r v i c e , Marine S c i e n c e Branch, Department o f t h e Environment, Ottawa, Canada. DAHL, F i n n - E . 1 9 7 7 . A Note on H o r i z o n t a l G r a d i e n t s i n F j o r d s . O c e a n o g . 7_(5): 7 5 3 - 7 5 8 . Jour. Phys. DEFANT, A l b e r t . 1 9 6 1 . P h y s i c a l Oceanography, DRINKWATER, K e n n e t h Vol. I I . Pergamon P r e s s . F. 1 9 7 3 . The R o l e o f T i d a l M i x i n g i n R u p e r t a n d H o l b e r g M. S c . T h e s i s , U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. p p . 5 8 . Inlets. ECKART, C a r l . 1 9 4 8 . An A n a l y s i s o f t h e S t i r r i n g and M i x i n g P r o c e s s e s i n Incompressible Fluids. J o u r . Mar. Res. VII,3:265-275. E L L I O T T , J . A . a n d N.S. OAKEY. 1 9 7 5 . H o r i z o n t a l coherence o f Temperature J o u r . P h y s . O c e a n o g . 5_: 5 0 6 - 5 1 5 . Microstructure. GARGETT, A n n . 1976. An I n v e s t i g a t i o n o f t h e Occurrence o f Oceanic T u r b u l e n c e w i t h r e s p e c t t o F i n e s t r u c t u r e . J o u r . Phys. Oceanog. 6:139-156. GREGG, M.C. a n d C.S. COX.,1972. The V e r t i c a l M i c r o s t r u c t u r e o f T e m p e r a t u r e Deep S e a R e s . 1 9 : 3 5 5 - 3 7 6 . GREGG, M . C , C.S. COX a n d P.W. and Salinity. HACKER. 1 9 7 3 . V e r t i c a l M i c r o s t r u c t u r e Measurements i n t h e C e n t r a l North P a c i f i c . J o u r . P h y s . Oceanog.' _3:458-469. Institute o f Oceanography o f t h e U n i v e r s i t y o f B r i t i s h Columbia. 1973. D a t a R e p o r t 34. B r i t i s h C o l u m b i a I n l e t s a n d P a c i f i c C r u i s e s 1972. U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. Institute o f Oceanography o f t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a . 1974. D a t a R e p o r t 35. B r i t i s h C o l u m b i a I n l e t C r u i s e s 1 9 7 3 . U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. Institute o f Oceanography o f t h e U n i v e r s i t y o f B r i t i s h Columbia. 1975. D a t a R e p o r t 37. B r i t i s h C o l u m b i a I n l e t C r u i s e s 1 9 7 4 . U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. LUECK, R o l f G., Owen HERTZMAN a n d Thomas R. OSBORN. 1 9 7 7 . The S p e c t r a l R e s p o n s e o f T h e r m i s t o r s . Res. 24:951-970. Deep S e a MONIN, A . S . 1 9 7 7 . Variability o f t h e Oceans. John W i l e y and Sons. OSBORN, T.R. a n d C.S. COX. 1 9 7 2 . Oceanic Fine Structure. G e o p h y s . F l u i d D y n . _3:321-345. OSBORN, T.R. 1977. The D e s i g n a n d P e r f o r m a n c e o f F r e e F a l l M i c r o s t r u c t u r e Instruments a t t h e I n s t i t u t e o f Oceanography. U n p u b l i s h e d m a n u s c r i p t , I n s t i t u t e o f Oceanography, U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. P I C K A R D , G.L. 1 9 7 5 . A n n u a l a n d L o n g e r T e r m V a r i a t i o n s o f Deep W a t e r P r o p e r t i e s i n C o a s t a l Waters of Southern B r i t i s h Columbia. J o u r . F i s h . R e s . B o a r d Canada 32:1561-1587. STOMMEL, H. a n d K.N. FEDOROV. 1 9 6 7 . S m a l l S c a l e S t r u c t u r e i n Temperature and S a l i n i t y near Timor and Mindanao. T e l l u s 19(2):306-325. TURNER, J . S . 1973. Buoyancy E f f e c t s i n F l u i d s . P r e s s , 367 p p . Cambridge University 75 Drop Number Location Date ( 3 R a m i l l i e s Channel 1 9 7 4 Hour ) 5 Feb. 09:25 Separation a t launch Separation a t recovery ±10% ±50% 15 m 10 m 4 " " " 11:00 7 m N/A 5 " " " 13:40 3m 20 m 6 " " " 14:10 20 m N/A 6 Feb. 09:10 20 m 25 m 12 m 7 S t a t i o n Howe 4 8 " " " 10:10 3m 9 " " " 11:15 10 m " 12:55 20 m " 14:00 3 m 10 11 S t a t i o n Howe 4.7 " " Table I L i s t o f t h e d o u b l e d r o p s made i n t h e F e b r u a r y 1974 c r u i s e i n Howe S o u n d ' s b a s i n s , t o g e t h e r w i t h the s e p a r a t i o n o f t h e probes a t launch and a t recovery. N/A 1 m N/A 76 Drop Number Date Time Location Mean Square Gradient 10 (1973) 3 (C°/m) Depth Interval 2 (m) 10:25 Howe 4 11.0 38 183 P-ll 11:20 Howe 3.8 18.0 27 210 P-12 12:30 Howe 4 46.9 28 152 P-13 13:30 Howe 4 18.2 27 187 P-14 14:10 Howe 4 22.8 19 202 P-15 15:20 Howe 4 39.2 28 70 08:43 Howe 4.7 17.2 28 183 P-10 P-16 21 N o v . 22 Nov. Table I I T i m e s a n d l o c a t i o n s a t w h i c h D r o p s P-10 t o P-16 w e r e made d u r i n g t h e November 1 9 7 3 c r u i s e i n Howe S o u n d . The v a l u e s o f t h e mean s q u a r e g r a d i e n t s a n d t h e d e p t h i n t e r v a l s over which they were observed a r e a l s o g i v e n . The mean t e m p e r a t u r e g r a d i e n t s o v e r t h e s e i n t e r v a l s was not c a l c u l a t e d because major temperature t h e p r o f i l e s p r e s e n t numerous inversions. 77 D r o p Number Intermediate Thickness Water (m) Temperature Change (C°) Mean S q u a r e Gradient (C°/m) 2 6-A 152 2.0 35. 6- B 162 1.8 18. 7-A 80 1.1 6.2 7- B 79 1.3 9.8 8- A 89 1.5 7.1 8- B 85 1.4 11.4 9- A 82 1.4 8.3 9-B 83 1.5 9.0 10-A 83 1.5 9.0 10-B 85 1.4 8.1 Table III T e m p e r a t u r e change and g r a d i e n t v a r i a n c e found i n t h e I n t e r m e d i a t e Water i n F e b r u a r y 1974. x 10 3 78 79 Figure 2 Longitudinal section of Howe Sound and cross channel sections made at the s i l l ( ) and at Howe 4 ( ). 0 T(°C) 7 9 S(%o) 29 31 T(°C) 7 9 S(%o) 29 31 100k 200 Outer Easin Inner Basin Figure 3 Typical winter profiles of temperature and salinity in the Outer Basin and in the Inner Basin (February 1974) CO o 81 Temperature O O) o oo (°C) n o 82 Outer Basin Howe 2 8*3 10 U 8 cL E 6 6 30.4 _30.4 o 4- 3 0 . 0 °: 3o.o >* 4 29.6 c 29.6 29.4 SALINITY oo 2 9 . 4 74 1973 1972 Inner Basin Howe 4.5 10 8 J J ( 6 A,SO . N D . J . F M A M . J . J A,S O . N . D . J j ^ 30.4 + 30.0 oo 29.4 1973 1972 Figure 5 Comparison values in between the temperature and s a l i n i t y average the Intermediate Water of the Inner and Outer Basin. a) u o t9 200m / \ a E 200m + 8 100m 100m TEMPERATURE 0) -t-H——I—I—I—1—I—t N D'J F i i I I I N D'J F ' ' i i i i i 1973 1972 30.06 f ' ' • i I I ND'J F I i i i 1974 b) + 30.06 200m 30.04 + ~ , o o o A-S- N "\ o o • •• o o / / 4-30.04 \ V lOOm 30.021 4- 3 0 . 0 2 SALINITY H—h-H—I—I—I—I—I—I—IH—H N D ' J F N D ' J F 1972 Figure - J — I — I — i — i — i — i — i — t - 1973 6 a) and -I—i—i—I—i- ND'J F b) 1974 Key t o Symbols: a 250 m A 225m __200m o 175 m O 150m • 125 m — 100m 84 CM —h- — CD a z < ©C5<i0 E •090 o e o o e <3aQ O <J8i CM > CD |<D /•O o VCJ T3 1 0> 0) Q Z 3 60 •H fe /•OO / OQ CM T3 > c o O) u. -> >} Q -4- O O CD O lO O CM CM CM 1- euu6!S -4- Q Z 01 CM ( |/|UJ)-0'Q t- C SURFACE LAYER 1 | F i gure 7 L o n g i t u d i n a l s e c t i o n o f Howe Sound showing what i s meant by Deep Water and I n t e r m e d i a t e Water. CO Figure 8 87 Figure 9 Figure 10 NOVEMBER 25 26 27 28 29 30 E 1 2 3 5 A 6 7 U 1 J2f."i29.^c§.iy_r?_§i1 J^-Q M J ° c) 8 • I0i J o 31 8 9 10 11 12 13 14 15 [-9 0 O .if •8 r»10 • 0 -10 M re 0 -10 J 1^ n 3 Ul n N-S C u r r e n t at 150M (cm/sec) H* 00 C >-f ft) ft 2 V P r e d i c t i o n of Tidal E x c u r s i o n s 0 wr N 10 J", (M) o N 'i •10 0 iV 10_ Wind Record at Squamish ( M / s e c ) o J V 11?, 600 300-I 0 L 3 « 10 s 600 Squamish River Discharge (M7sec) -i r~ I -300 £ n 0 CO ^3 COATING Figure 12 91 DROP P-16 (HOWE 4.7, EAST SIDE) DROP P-]0 DROP P-12 DROP P-13 DROP P-14 DROP P-15 (HOWE 4) DROP P - l l (HOWE 3.8) .SILL Fi gure 1 3 L o c a t i o n o f t h e temperature m i c r o s t r u c t u r e profiles made d u r i n g t h e November 1973 c r u i s e i n Howe Sound. F i g u r e 14 O v e r a l l p r o f i l e o f D r o p P-10 F i g u r e ,15 O v e r a l l p r o f i l e of Drop P-ll 94 Figure Overall profile 16 o f D r o p P-12 Figure 17 O v e r a l l p r o f i l e o f D r o p P-13 Figure 18 O v e r a l l p r o f i l e o f D r o p P-14 F i g u r e 20 Overall profile o f D r o p P-16 i r r i + + + + + + + + + + 8.4 8.6 8,8 I L 2.0 TEMPERATUFE (°C) 0.0 Gradient (C /m) F i g u r e 21 Detailed profile f r o m drop P-12, •2.( Figure Detailed profile 22 from drop P-12. Figure 23 Detailed profile from drop P-13, 102 1 1 W 1• TEMPERATURE ( C) 0 GRADIENT F i g u r e 24 Detailed profile f r o m d r o p P-13. - 1 - 2 (C°/m) 1 103 Figure 25 STD in l o n g c h a n n e l s e c t i o n made on November Howe S o u n d ' s b o t h basins. 13,1973 104 Figure STD cross 26 c h a n n e l s e c t i o n made o n N o v e m b e r a t s t a t i o n Howe 4 ( I n n e r B a s i n ) . 22,1973 Q O O o o O O CM /—\ m o o tu i 00 I 2 Figure STD c r o s s channel •> 5 s o 27 s e c t i o n made on No-vember a t s t a t i o n Howe 4.7 ( I n n e r Basin). 22,1973 oo vo —' O 106 F i g u r e 28 Location o f the temperature made d u r i n g t h e F e b r u a r y microstructure 1974 c r u i s e profiles i n Howe S o u n d . TEMPERATURE C O R M S . G R A D I E N T lc°/m) M E A N GRADIENT (c'/m) 110 Figure 32 O v e r a l l p r o f i l e of Drop 9 Figure 33 Overall p r o f i l e of Drop 10 112 TEMPERATURE R # M - S > Figure 34 Deep p a r t o f Drop 7 with an e x p a n d e d t e m p e r a t u r e scale. VERTICAL 113 R.M.S. VERTICAL GRADIENT (C°/m) TEMPERATURE C°c) 7.5 7.7 J 7.9 ! : 8.1 i I I 8.3 J 1.0 ! l_ 200 F i g u r e 35 Deep p a r t o f Drop 8 w i t h an e x p a n d e d t e m p e r a t u r e scale. 114 Figure 36 Deep p a r t o f D r o p 9 w i t h an e x p a n d e d t e m p e r a t u r e scale. 115 Figure Deep p a r t of D r o p 10 w i t h 37 an e x p a n d e d t e m p e r a t u r e scale. 116 Temperature ( C) 100 Depth (m) 150 J 200 250 Figure Comparison before and d u r i n g On t h e l e f t , 38 between temperature profiles t h e F e b r u a r y 1974 m i c r o s t r u c t u r e profiles from the Outer Basin: S t a t i o n Howe 3, J a n u a r y 2 2 , 1 9 7 4 . Ramilles t a k e n two weeks Channel, On t h e r i g h t , p r o f i l e s F e b r u a r y 5, 1 9 7 4 . from t h e I n n e r Basin: S t a t i o n Howe 4 . 5 , J a n u a r y 2 3 , 1 9 7 4 . S t a t i o n Howe 4 . 5 , F e b r u a r y 6, 1 9 7 4 . cruise. F i g u r e 39 STD l o n g c h a n n e l s e c t i o n made i n Howe S o u n d ' s I n n e r B a s i n on F e b r u a r y 6,1974. F i g u r e 40 STD c r o s s channel s e c t i o n made at s t a t i o n Howe 4 on F e b r u a r y 6, 1974. 119 I C '•H •a l r~v——wi„ 00 Figure 41 Detailed p r o f i l e from Drop 6 in o Figure 42 Detailed p r o f i l e from Drop 6. to o 121 F i g u r e 44 Detailed profile f r o m Drop 7 123 F i g u r e 45 Detailed profile from Drop 7 F i g u r e 46 Detailed profile from Drop 7 125 Figure 47 Detailed profile from Drop 8 126 F i g u r e 48 Detailed profile f r o m Drop 8 127 128 Figure Detailed 50 profile from Drop 9 129 Figure 51 Detailed profile from Drop 9 130 F i g u r e 52 D e t a i l e d p r o f i l e from Drop 10 131 ^ m o 4ruJ L 132 F i g u r e 54 Detailed profile f r o m D r o p 10 133 Figure Detailed profile 55 f r o m t h e Deep W a t e r o f D r o p 7 Figure tailed profile 56 f r o m t h e Deep W a t e r o f D r o p 7 135 . — E o u i1 - o Figure Detailed profile 57 f r o m t h e Deep W a t e r o f D r o p 8
Featured Collection
UBC Theses and Dissertations
Temperature microstructure in Howe Sound Bilodeau, Laurent Ernest 1979
Item Metadata
Download
- Media
- 831-UBC_1979_A6_7 B44.pdf [ 4.57MB ]
- Metadata
- JSON: 831-1.0053180.json
- JSON-LD: 831-1.0053180-ld.json
- RDF/XML (Pretty): 831-1.0053180-rdf.xml
- RDF/JSON: 831-1.0053180-rdf.json
- Turtle: 831-1.0053180-turtle.txt
- N-Triples: 831-1.0053180-rdf-ntriples.txt
- Original Record: 831-1.0053180-source.json
- Full Text
- 831-1.0053180-fulltext.txt
- Citation
- 831-1.0053180.ris
Full Text
Cite
Citation Scheme:
Usage Statistics
Share
Embed
Customize your widget with the following options, then copy and paste the code below into the HTML
of your page to embed this item in your website.
<div id="ubcOpenCollectionsWidgetDisplay">
<script id="ubcOpenCollectionsWidget"
src="{[{embed.src}]}"
data-item="{[{embed.item}]}"
data-collection="{[{embed.collection}]}"
data-metadata="{[{embed.showMetadata}]}"
data-width="{[{embed.width}]}"
async >
</script>
</div>
Our image viewer uses the IIIF 2.0 standard.
To load this item in other compatible viewers, use this url: http://iiif.library.ubc.ca/presentation/dsp.831.1-0053180/manifest