TITLE:
Air-Water Carbon Dioxide Exchange in the Littoral Zone of Lake Baikal (Ice-Free Period)
AUTHORS:
Valentina M. Domysheva, Mikhail V. Panchenko, Dmitry A. Pestunov, Mariya V. Sakirko
KEYWORDS:
Gas Exchange; Carbon Dioxide Flux; Dissolved Gases; Nutrients
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.10,
December
25,
2013
ABSTRACT:
Lake Baikal is one of the most unique natural environments in Siberia, and it affects to a large extent the natural state in this region. Processes of gas exchange in the air-water system have been studied in Lake Baikal since 2002. Measurements have been carried out in the littoral area on the western shore of Southern Baikal (51°51'N, 105°04'E). The method of accumulative chambers was prioritized for measuring carbon dioxide fluxes in the air-water system. Chemical analysis of the water samples collected every three hours at the chamber locations was carried out in the on-land laboratory. We measured pH, content of dissolved oxygen, bicarbonate, nitrate and phosphate. The CO2 content in the water was measured from pH values and the bicarbonate concentration. The total sink of CO2 on the water surface is increasing in the littoral area of Lake Baikal from 20 mg·CO2·m-2·day-1 in June to 110 mg·CO2·m-2·day-1 in August. The decrease in the flux rate usually begins in September from 95 mg·CO2·m-2·day-1 to the zero balance in late October - early November. The maximal rate of mean diurnal CO2 emissions is recorded in December in the pre-ice period (110 mg·CO2·m-2·day-1). Based on the long-term measurements during all seasons, the sink of atmospheric CO2 in the littoral zones of Lake Baikal was estimated to be 3 - 5 g·CO2·m-2.