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Temperature and salt content regimes in three shallow ice-covered lakes 1. Temperature, salt content, and density structure

Malm, J.; Terzhevik, A.; Bengtsson, Lars LU ; Boyarinov, P.; Glinsky, A.; Palshin, N. and Petrov, M. (1997) In Nordic Hydrology 28(2). p.99-128
Abstract
A field study on the temperature, salt content, and density regime in three shallow ice-covered Karelian lakes is presented. The measurements show that the heat content increases during the whole ice-covered period. At ice formation a weak stable stratification existed in the lakes, with average temperatures about 1 degrees C. Thereafter, the stability of the stratification gradually increased, mainly due to pronounced temperature increases in the bottom layers. In mid-winter the bottom layer in the deep parts of the lakes obtained temperatures above 4 degrees C. The density stratification in these layers was stable, however, due to higher salt contents (increasing continuously during the winter) in the vicinity of the bottom. The... (More)
A field study on the temperature, salt content, and density regime in three shallow ice-covered Karelian lakes is presented. The measurements show that the heat content increases during the whole ice-covered period. At ice formation a weak stable stratification existed in the lakes, with average temperatures about 1 degrees C. Thereafter, the stability of the stratification gradually increased, mainly due to pronounced temperature increases in the bottom layers. In mid-winter the bottom layer in the deep parts of the lakes obtained temperatures above 4 degrees C. The density stratification in these layers was stable, however, due to higher salt contents (increasing continuously during the winter) in the vicinity of the bottom. The horizontal variations in temperature and salt content were very small, and both parameters can be considered to be horizontally homogeneous. Under-ice convection was developed in two of the three investigated lakes during the second half of April, when heating due to penetrating solar radiation became apparent. Although no under-ice convection in the conventional sense occurred in the third lake (Uros), interior convection developed when the temperature exceeded 4 degrees C (the temperature of maximum density) there. The absence of under-ice convection in Lake Uros is most likely due to the higher vertical temperature gradient in the lake before spring heating and smaller extinction coefficient than in the other two lakes. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nordic Hydrology
volume
28
issue
2
pages
99 - 128
publisher
IWA Publishing
external identifiers
  • scopus:0031450297
ISSN
1996-9694
DOI
10.2166/nh.1997.007
language
English
LU publication?
yes
id
87e0ac48-1672-46a6-b222-feaa4583fd1e (old id 2595364)
date added to LUP
2012-05-31 17:05:42
date last changed
2017-07-09 03:47:48
@article{87e0ac48-1672-46a6-b222-feaa4583fd1e,
  abstract     = {A field study on the temperature, salt content, and density regime in three shallow ice-covered Karelian lakes is presented. The measurements show that the heat content increases during the whole ice-covered period. At ice formation a weak stable stratification existed in the lakes, with average temperatures about 1 degrees C. Thereafter, the stability of the stratification gradually increased, mainly due to pronounced temperature increases in the bottom layers. In mid-winter the bottom layer in the deep parts of the lakes obtained temperatures above 4 degrees C. The density stratification in these layers was stable, however, due to higher salt contents (increasing continuously during the winter) in the vicinity of the bottom. The horizontal variations in temperature and salt content were very small, and both parameters can be considered to be horizontally homogeneous. Under-ice convection was developed in two of the three investigated lakes during the second half of April, when heating due to penetrating solar radiation became apparent. Although no under-ice convection in the conventional sense occurred in the third lake (Uros), interior convection developed when the temperature exceeded 4 degrees C (the temperature of maximum density) there. The absence of under-ice convection in Lake Uros is most likely due to the higher vertical temperature gradient in the lake before spring heating and smaller extinction coefficient than in the other two lakes.},
  author       = {Malm, J. and Terzhevik, A. and Bengtsson, Lars and Boyarinov, P. and Glinsky, A. and Palshin, N. and Petrov, M.},
  issn         = {1996-9694},
  language     = {eng},
  number       = {2},
  pages        = {99--128},
  publisher    = {IWA Publishing},
  series       = {Nordic Hydrology},
  title        = {Temperature and salt content regimes in three shallow ice-covered lakes 1. Temperature, salt content, and density structure},
  url          = {http://dx.doi.org/10.2166/nh.1997.007},
  volume       = {28},
  year         = {1997},
}