Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

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

In English

Författare

Summary, in English

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.

Publiceringsår

1997

Språk

Engelska

Sidor

99-128

Publikation/Tidskrift/Serie

Nordic Hydrology

Volym

28

Issue

2

Dokumenttyp

Artikel i tidskrift

Ämne

  • Water Engineering

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0029-1277