- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Faculty Research and Publications /
- Estuarine forcing of a river plume by river flow and...
Open Collections
UBC Faculty Research and Publications
Estuarine forcing of a river plume by river flow and tides Halverson, Mark J.; Pawlowicz, Rich
Abstract
Estuarine forcing of a river plume by river discharge and tides is examined with a novel data set capable of characterizing semidiurnal to annual time scales. An instrumented ferry made high‐resolution salinity measurements as it crossed the Fraser River plume, British Columbia, Canada, eight times per day over the years 2003–2006. The relative contribution of different forcing factors in controlling the river plume salinity and surface area is examined over the full range of time scales. A Lomb‐Scargle periodogram of the plume salinity shows energy concentrated in the semidiurnal and diurnal tidal bands. Diurnal lines contain more energy relative to semidiurnal lines than the respective tidal constituents would suggest. At fortnightly frequencies, local maxima in plume salinity coincide with periods of maxima in daily tidal height, with no phase shift. Thus the estuary adjusts quickly to changes in forcing. The effectiveness of tides in setting the plume salinity is a function of river discharge and is greatest when the river discharge is high and minimal when the river discharge is low. Tidal effects are superimposed onto the long‐period river discharge cycle. At time scales of 25 days or longer, the mean river plume salinity decreases quasi‐linearly with increasing river discharge, but the change in salinity with river discharge is instantaneous to within the sampling resolution. Plume surface area increases with river discharge, from 200–500 km2 at low river flow to 1000–1500 km2 at high river flow. The magnitude of the surface area is predicted well by scaling the mouth deformation radius. An edited version of this paper was published by AGU. Copyright (year) American Geophysical Union. An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union.
Item Metadata
Title |
Estuarine forcing of a river plume by river flow and tides
|
Creator | |
Publisher |
American Geophysical Union
|
Date Issued |
2008-09
|
Description |
Estuarine forcing of a river plume by river discharge and tides is examined with a novel data set capable of characterizing semidiurnal to annual time scales. An instrumented ferry made high‐resolution salinity measurements as it crossed the Fraser River plume, British Columbia, Canada, eight times per day over the years 2003–2006. The relative contribution of different forcing factors in controlling the river plume salinity and surface area is examined over the full range of time scales. A Lomb‐Scargle periodogram of the plume salinity shows energy concentrated in the semidiurnal and diurnal tidal bands. Diurnal lines contain more energy relative to semidiurnal lines than the respective tidal constituents would suggest. At fortnightly frequencies, local maxima in plume salinity coincide with periods of maxima in daily tidal height, with no phase shift. Thus the estuary adjusts quickly to changes in forcing. The effectiveness of tides in setting the plume salinity is a function of river discharge and is greatest when the river discharge is high and minimal when the river discharge is low. Tidal effects are superimposed onto the long‐period river discharge cycle. At time scales of 25 days or longer, the mean river plume salinity decreases quasi‐linearly with increasing river discharge, but the change in salinity with river discharge is instantaneous to within the sampling resolution. Plume surface area increases with river discharge, from 200–500 km2 at low river flow to 1000–1500 km2 at high river flow. The magnitude of the surface area is predicted well by scaling the mouth deformation radius. An edited version of this paper was published by AGU. Copyright (year) American Geophysical Union. An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2011-05-31
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
Attribution-NonCommercial-NoDerivatives 4.0 International
|
DOI |
10.14288/1.0041941
|
URI | |
Affiliation | |
Citation |
Halverson, Mark J.; Pawlowicz, Rich. 2008. Estuarine forcing of a river plume by river flow and tides. Journal of Geophysical Research Oceans 113(9) C09033
|
Publisher DOI |
10.1029/2008JC004844
|
Peer Review Status |
Reviewed
|
Scholarly Level |
Faculty
|
Copyright Holder |
Pawlowicz, Rich
|
Rights URI | |
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International