The Open Collections site will undergo maintenance from 4:00 PM - 6:00 PM PT on Wednesday, April 2nd, 2025. During this time, images and the IIIF service will not be available.
- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Mixing processes from CTD profiles using a lake-specific...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Mixing processes from CTD profiles using a lake-specific equation of state : Quesnel Lake James, Christina
Abstract
Quesnel Lake, is a deep (511m maximum depth) fjord-type lake in northeast British Columbia, Canada. Mixing processes in the lake exchange deep-water with surface water and contribute to the renewal of surface-water nutrients and oxygenated deep-water. These processes are of great consequence to the lake's trophic dynamics and understanding them will enable better management of the large salmon resources in Quesnel Lake. To better understand large-scale convective processes, a lake-specific equation of state was developed. Water samples were collected at locations around Quesnel Lake and analysed for ionic and non-ionic composition as well as other quantities that are integral to determining the lake's equation of state including pH, alkalinity and specific conductance. A relationship was developed to find lake water salinity from CTD data. Salinity was in turn related to density using a modified form of a general limnological equation of state. The equation of state developed for Quesnel Lake gives densities accurate to ± 0.0018kg/m³ whereas the general equation of state (based on seawater composition) is only accurate to ± 0.0158kg/m³ for Quesnel Lake water samples. The lake-specific equation of state was used to identify gravitational instability in density profiles estimated from CTD data. In order to compare water parcel density within a profile, the hydrostatic pressure effect must be removed. The three quantities that are used for this purpose, potential density, quasi-density and standard density, were compared. Quasi-density was found to be most appropriate for Quesnel Lake's deep water which is near the temperature of maximum density. Quesnel lake water column stability was quantified using the Brunt-Vaisala frequency calculated using quasi-density.
Item Metadata
| Title |
Mixing processes from CTD profiles using a lake-specific equation of state : Quesnel Lake
|
| Creator | |
| Publisher |
University of British Columbia
|
| Date Issued |
2004
|
| Description |
Quesnel Lake, is a deep (511m maximum depth) fjord-type lake in northeast
British Columbia, Canada. Mixing processes in the lake exchange deep-water
with surface water and contribute to the renewal of surface-water nutrients and
oxygenated deep-water. These processes are of great consequence to the lake's
trophic dynamics and understanding them will enable better management of
the large salmon resources in Quesnel Lake.
To better understand large-scale convective processes, a lake-specific equation
of state was developed. Water samples were collected at locations around
Quesnel Lake and analysed for ionic and non-ionic composition as well as other
quantities that are integral to determining the lake's equation of state including
pH, alkalinity and specific conductance. A relationship was developed to
find lake water salinity from CTD data. Salinity was in turn related to density
using a modified form of a general limnological equation of state. The equation
of state developed for Quesnel Lake gives densities accurate to ± 0.0018kg/m³
whereas the general equation of state (based on seawater composition) is only
accurate to ± 0.0158kg/m³ for Quesnel Lake water samples.
The lake-specific equation of state was used to identify gravitational instability
in density profiles estimated from CTD data. In order to compare water
parcel density within a profile, the hydrostatic pressure effect must be removed.
The three quantities that are used for this purpose, potential density, quasi-density
and standard density, were compared. Quasi-density was found to be
most appropriate for Quesnel Lake's deep water which is near the temperature
of maximum density. Quesnel lake water column stability was quantified using
the Brunt-Vaisala frequency calculated using quasi-density.
|
| Extent |
4965283 bytes
|
| Genre | |
| Type | |
| File Format |
application/pdf
|
| Language |
eng
|
| Date Available |
2009-12-03
|
| Provider |
Vancouver : University of British Columbia Library
|
| Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
| DOI |
10.14288/1.0063438
|
| URI | |
| Degree | |
| Program | |
| Affiliation | |
| Degree Grantor |
University of British Columbia
|
| Graduation Date |
2005-05
|
| Campus | |
| Scholarly Level |
Graduate
|
| Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.