Abstracts

Water Ecosystems

At the present stage of monitoring and research of limnological processes can not be effective without the carefully organized system of accumulation, storage and fast call of a necessary information and submission it in visual and accessible to the form. The harmonisation of Lake Ladoga ecological parameters is a very important procedure for the solution of a many limnological tasks, connected with the environment problems and its ecological modelling.

The best realisation of these circumstances can achieve using thematic databases. Many of Lake Ladoga researchers (Homen, Molchanov, Tikhomirov) tried to describe a main thermal features of the largest European freshwater basin (volume 838 km3, mean depth 47 m.) by thermal surveys conducted .

Main efforts of authors were directed on the collection of archive information of Lake Ladoga hydrophysical water parameters and making a thermal database. At present time the database is firstly created at Institute for Lake Research Russian Academy of Sciences. It includes the field measurements of water thermal characteristic and meteorological parameters for period from 1898 to 2000 years. This database consists of more then 150 thousand strings of water temperature with accompanying parameters, covered 74 years . Total data density equals about 175 measurements per cu. km. It is the very large database among word lakes. Morphometrical model of Lake Ladoga was produced earlier.

Various statistics of water temperatures were calculated for different seasons, regions and horizons of the lake. It has shown there are a considerable temperature variations up to 50 m depth from June to September.

The portion of nonseasonal temperature variability in total dispersion has been estimated by the compositional approximation.

Initially the developed information-diagnostic system (IDS) has allowed to receive the daily spatial distributions of Lake Ladoga water surface and air temperature for open water period, which can serve as mean climatological distributions at synoptic variability analysis and interannual variations.

The scheme of spring frontal zone (thermobar) evolution was built.

The scheme of "biological summer" duration (period which the water has a temperature above 10 ºС) for water surface was built.

The schemes of values and dates of water temperatures maximum coming are presented.

Lake Ladoga information-diagnostic system was used for investigation of water surface layer and atmosphere thermal interaction and Volkhov bay ecological conditions.

Created information-diagnostic system gives new possibilities at a solution of the various tasks on thermodynamic of Lake Ladoga and its simulation.

Note. Abstracts are published in author's edition

|Home Page| |English Part|

Go to Home