The large-scale atmospheric circulation pattern over Asia associated with formation of extremely high surface ozone concentrations in the region of Tomsk (Western Siberia)
O.Yu. Antokhina, P.N. Antokhin, V.G. Arshinova, M.Yu. Arshinov, B.D. Belan, S.B. Belan, D.K. Davydov, G.A. Ivlev, A.V. Kozlov, T.M. Rasskazchikova, D.E. Savkin, D.V. Simonenkov, T.K. Sklyadneva, G.N. Tolmachev, A.V. Fofonov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: the surface ozone concentration, atmospheric circulation, pattern, air mass, budget
Abstract
Based on ERA 5 reanalysis data and average daily surface ozone concentrations (O3) measured at the TOR station from 1993 to 2020, the circulation mode, which contributes to the formation of extremely high ozone concentrations (95th percentile, further О395), is studied. It is found that for all months; an identical circulation mode is distinguished, characterized by an increase in surface air temperature in the area, which includes the TOR station. In addition to the increase in air temperature, О395 events are characterized by an increase in the southwestern component of wind speed. It was also found that these circulation features are associated with the development of meridionality, probably due to the propagation of waves in midlatitudes. The revealed circulation mode simultaneously contributes to the transboundary transfer of ozone and its precursors from the southern regions, the enhancement of ozone photochemistry, and the emergence of an additional source of ozone precursors - wildfires.
|
