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Investigation of the spring thermal regime in Lake Ladoga using field and satellite data

Malm, Joakim LU ; Mironov, Dmitry ; Terzhevik, Arkady and Jönsson, Lennart LU (1994) In Limnology and Oceanography 39(6). p.1333-1333
Abstract
We use a combination of field and satellite data to investigate the thermal regime in Lake Ladoga in spring 1992. The analysis concentrates mainly on the temperature structure in the convectively mixed region and the dynamics of a special thermo‐hydrodynamic phenomenon called “thermal bar” (a zone of descending water with the temperature of maximum density equal to ∼4°C). A theoretical model of the temperature distribution in the convectively mixed region (temperatures <4°C) and the thermal bar progression is also applied and compared with satellite data.

The study shows that the temperature offshore the 4°C isotherm in the convectively mixed region of the lake is almost depth‐constant because of strong convective mixing and... (More)
We use a combination of field and satellite data to investigate the thermal regime in Lake Ladoga in spring 1992. The analysis concentrates mainly on the temperature structure in the convectively mixed region and the dynamics of a special thermo‐hydrodynamic phenomenon called “thermal bar” (a zone of descending water with the temperature of maximum density equal to ∼4°C). A theoretical model of the temperature distribution in the convectively mixed region (temperatures <4°C) and the thermal bar progression is also applied and compared with satellite data.

The study shows that the temperature offshore the 4°C isotherm in the convectively mixed region of the lake is almost depth‐constant because of strong convective mixing and that the horizontal heat flux seems to be of minor importance in this region. The comparison between predictions from the simple theoretical model describing the temperature evolution and movement of the thermal bar with observations showed a fairly good agreement. However, calculations of the change of heat content in water columns along sections indicate heat transport from the nearshore, stably stratified region toward the 4°C isotherm which will affect the movement of the thermal bar. This effect has been incorporated in an improved model of the thermal bar progression. A better agreement between predictions and observations was also obtained with this model. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Limnology and Oceanography
volume
39
issue
6
pages
1348 pages
publisher
ASLO
external identifiers
  • scopus:0028570336
ISSN
1939-5590
DOI
10.4319/lo.1994.39.6.1333
language
English
LU publication?
yes
id
a2bf84f4-366a-4d5c-9cc8-eb071fef7883
date added to LUP
2019-10-26 01:44:11
date last changed
2021-12-02 10:33:45
@article{a2bf84f4-366a-4d5c-9cc8-eb071fef7883,
  abstract     = {{We use a combination of field and satellite data to investigate the thermal regime in Lake Ladoga in spring 1992. The analysis concentrates mainly on the temperature structure in the convectively mixed region and the dynamics of a special thermo‐hydrodynamic phenomenon called “thermal bar” (a zone of descending water with the temperature of maximum density equal to ∼4°C). A theoretical model of the temperature distribution in the convectively mixed region (temperatures &lt;4°C) and the thermal bar progression is also applied and compared with satellite data.<br>
<br>
The study shows that the temperature offshore the 4°C isotherm in the convectively mixed region of the lake is almost depth‐constant because of strong convective mixing and that the horizontal heat flux seems to be of minor importance in this region. The comparison between predictions from the simple theoretical model describing the temperature evolution and movement of the thermal bar with observations showed a fairly good agreement. However, calculations of the change of heat content in water columns along sections indicate heat transport from the nearshore, stably stratified region toward the 4°C isotherm which will affect the movement of the thermal bar. This effect has been incorporated in an improved model of the thermal bar progression. A better agreement between predictions and observations was also obtained with this model.}},
  author       = {{Malm, Joakim and Mironov, Dmitry and Terzhevik, Arkady and Jönsson, Lennart}},
  issn         = {{1939-5590}},
  language     = {{eng}},
  number       = {{6}},
  pages        = {{1333--1333}},
  publisher    = {{ASLO}},
  series       = {{Limnology and Oceanography}},
  title        = {{Investigation of the spring thermal regime in Lake Ladoga using field and satellite data}},
  url          = {{http://dx.doi.org/10.4319/lo.1994.39.6.1333}},
  doi          = {{10.4319/lo.1994.39.6.1333}},
  volume       = {{39}},
  year         = {{1994}},
}