The impact of atmospheric blocking in Western Siberia on changes in carbon dioxide and methane concentrations in winter
P.N. Antokhin1, O.Yu. Antokhina1, M.Yu. Arshinov1, B.D. Belan1, D.K. Davydov1, A.V. Kozlov1, A.V. Fofonov1, M. Sasakawa2, T. Machida2
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634055, Russia
2National Institute for Environmental Studies, 16-2 Onogawa, 305-8506, Tsukuba, Japan
Keywords: атмосферное блокирование, метан, углекислый газ, концентрация, JR-STATION, зимний период, высота пограничного слоя, приземное давление, atmospheric blocking, methane, carbon dioxide, concentration, winter period, JR-STATION, height of the boundary layer, surface pressure
Abstract
The paper proposes a mechanism for the influence of atmospheric blocking on the gas and aerosol composition of the surface layer of the atmosphere in the winter period. According to the mechanism proposed, an increase in the concentrations is observed in the cyclonic part of the blocking formed by the advection of polar air masses and more often localized in southern regions of Western Siberia. The increase in the concentrations occurs due to a decrease in the height of the boundary layer and the formation of inversion. To confirm the mechanism proposed, the variability of methane (CH4) and carbon dioxide (CO2) concentrations was studied in background regions of Western Siberia (JR-STATION - Japan-Russia Siberian Tower Inland Observation Network) during periods of atmospheric blocking. A total of 12 blocking periods were analyzed. It turned out that during the blocking period, the concentrations of CH4 and CO2 increase in most of the events for the stations located in the south of Western Siberia. The average difference in the CH4 concentrations between the blocking periods and the periods preceding the blockings was 133 ppb (range of variability is from 50 to 370 ppb), for CО2, 9.5 ppm (range of variability is from 4 to 17 ppm). The average growth rate of the concentration during the blocking periods was 48 ppb/day for CH4 (the maximum is 182 ppb/day, the minimum is 12 ppb/day), and for CO2, 3 ppm/day (the maximum is 9 ppm/day, the minimum is 1 ppb/day). The average increase for CH4 was 268 ppb, and for CO2, 17 ppm.
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