Analysis of the mechanisms, determining the direction and intensity of CO2 fluxes in the "atmosphere - water" system, seems to be important in the framework of the problem of increasing of the content of one of the greenhouse gases (carbon dioxide) in the atmosphere. The present paper starts the cycle of publications, devoted to analysis of seasonal peculiarities of the CO2 gas exchange process in the littoral zone of Southern Baikal and presents the results, obtained in spring. It is shown that the greatest transformation of all components of the carbon dioxide gas exchange process between the water surface in the atmosphere is observed during hydrological spring in the littoral zone of Lake Baikal. The amplitude of the diurnal behaviors of the concentrations of CO2, O2 and NO3- in water increases from May to June. The daily mean CO2 flux, which is directed to the atmosphere in the middle of May, changes its direction in June, and the well pronounced sink of CO2 to the water surface is observed. The tendency of increasing of the amplitude of the diurnal behavior of CO2 and intensification of the sink of carbon dioxide from the atmosphere to the water surface continues, and, on the average, by the middle of June, the sink can reach a value of 70 mg CO2 m-2Чday-1.
carbon dioxide, air - sea, gas exchange, Lake Baikal