Temperature distribution and current system in a convectively mixed lake
(1994) In Boundary-Layer Meteorology 71(3). p.219-234- Abstract
- During spring and autumn, many lakes in temperate latitudes experience intensive convective mixing in the vertical, which leads to almost isothermal conditions with depth. Thus the regime of turbulence appears to be similar with that characteristic of convective boundary layers in the atmosphere. In the present paper a simple analytical approach, based on boundary-layer theory, is applied to convective conditions in lakes. The aims of the paper are firstly to analyze in detail the temperature distribution during these periods, and secondly to investigate the current system, created by the horizontal temperature gradient and wind action. For these purposes, simple analytical solutions for the current velocities are derived under the... (More)
- During spring and autumn, many lakes in temperate latitudes experience intensive convective mixing in the vertical, which leads to almost isothermal conditions with depth. Thus the regime of turbulence appears to be similar with that characteristic of convective boundary layers in the atmosphere. In the present paper a simple analytical approach, based on boundary-layer theory, is applied to convective conditions in lakes. The aims of the paper are firstly to analyze in detail the temperature distribution during these periods, and secondly to investigate the current system, created by the horizontal temperature gradient and wind action. For these purposes, simple analytical solutions for the current velocities are derived under the assumption of depth-constant temperatures. The density-induced current velocities are shown to be small, in the order of a few mm/sec. The analytical model of wind-driven currents is compared with field data. The solution is in good qualitative agreement with observed current velocities under the condition that the wind field is steady for a relatively long time and that residual effects from former wind events are negligible.
The effect of the current system on an approximately depth-constant temperature distribution is then checked by using the obtained current velocity fields in the heat transfer equation and deriving an analytical solution for the corrected temperature field. These temperature corrections are shown to be small, which indicates that it is reasonable to describe the temperature distribution with vertical isotherms. (Less)
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https://lup.lub.lu.se/record/0a2e4e7e-bb58-448d-8f79-9a05b9ffde07
- author
- Malm, Joakim LU and Zilitinkevich, Sergei
- organization
- publishing date
- 1994
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Boundary-Layer Meteorology
- volume
- 71
- issue
- 3
- pages
- 219 - 234
- publisher
- Springer
- external identifiers
-
- scopus:0028668992
- ISSN
- 0006-8314
- DOI
- 10.1007/BF00713739
- language
- English
- LU publication?
- yes
- id
- 0a2e4e7e-bb58-448d-8f79-9a05b9ffde07
- date added to LUP
- 2019-10-26 01:52:11
- date last changed
- 2021-01-03 03:24:38
@article{0a2e4e7e-bb58-448d-8f79-9a05b9ffde07,
abstract = {{During spring and autumn, many lakes in temperate latitudes experience intensive convective mixing in the vertical, which leads to almost isothermal conditions with depth. Thus the regime of turbulence appears to be similar with that characteristic of convective boundary layers in the atmosphere. In the present paper a simple analytical approach, based on boundary-layer theory, is applied to convective conditions in lakes. The aims of the paper are firstly to analyze in detail the temperature distribution during these periods, and secondly to investigate the current system, created by the horizontal temperature gradient and wind action. For these purposes, simple analytical solutions for the current velocities are derived under the assumption of depth-constant temperatures. The density-induced current velocities are shown to be small, in the order of a few mm/sec. The analytical model of wind-driven currents is compared with field data. The solution is in good qualitative agreement with observed current velocities under the condition that the wind field is steady for a relatively long time and that residual effects from former wind events are negligible.<br/><br/>The effect of the current system on an approximately depth-constant temperature distribution is then checked by using the obtained current velocity fields in the heat transfer equation and deriving an analytical solution for the corrected temperature field. These temperature corrections are shown to be small, which indicates that it is reasonable to describe the temperature distribution with vertical isotherms.}},
author = {{Malm, Joakim and Zilitinkevich, Sergei}},
issn = {{0006-8314}},
language = {{eng}},
number = {{3}},
pages = {{219--234}},
publisher = {{Springer}},
series = {{Boundary-Layer Meteorology}},
title = {{Temperature distribution and current system in a convectively mixed lake}},
url = {{http://dx.doi.org/10.1007/BF00713739}},
doi = {{10.1007/BF00713739}},
volume = {{71}},
year = {{1994}},
}