Degree of Master of

Examination of the AALS thermal regime

CEU eTD Collection
To start with, examination of the AALS thermal regime was a very important practical issue in the 1970s because these lakes were a very suitable place for development of the fish industry. During the year-round field research in 1973-1974, investigations focused on the study of the AALS thermal regime, components of the AALS thermal balance, and hydrothermal surveys aimed to trace the patterns of thermal regime formation in the lake’s different parts were accomplished (Gorelkin and Nikitin 1976).
It has been found that presence of the numerous shallow zones from the north to the south extending more than 70 km in the East Arnasay as well as a large number of small bays in the Tuzkan lake and deep Aydarkul lake generates a distinctive thermal regime in these water bodies (Ivanov and Nikitin 1978).

2. Seasonal fluctuation of water temperature

Considering research of the seasonal fluctuations of AALS water temperature the following conclusions have been drawn:

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  according to the classification of the thermal regime, this system of lake was classified as lakes of middle latitudes with periods of spring-summer warming up and fall-winter cooling (Nikitin 1991);
  
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  temperature fluctuations between the bottom and surface of the deep-water Aydar lake make up 4-5˚C, increasing to 10-14˚C in June - July. Fluctuations of surface and bottom layers in the Tuzkan lake are 2-3˚C. Formation of homotermy conditions is often representative phenomena for the shallow-water East Arnasay lakes;
  
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  maximum monthly average water temperature is observed in July-August – 25-27˚C. In the middle of August the period of fall cooling starts. At the beginning of this period the temperature changes are not considerable, whereas in October-November the temperature decreases to 10˚C. Termination of fall cooling period depends on the specific weather conditions, but actually November-December are the last months of termination. Subsequent lake cooling up to freezing takes about 15-30 days. Usually freezing can be observed with 1-2˚C average water temperature. Then, in March-April the water temperature begins to grow starting from 5-7˚C and in May-June and goes up to more than 20˚C (Ivanov and Nikitin 1978).
  

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