Influence of atmospheric circulation on precipitation in Altai Mountains

01/01/2017

Abstract We analyzed the changes in precipitation regime in the Altai Mountains for 1959-2014 and estimate the influence of atmospheric circulations on these changes. Our study showed that during last 56 years the changes in the precipitation regime had a positive trend for the warm seasons (April-October), but weakly positive or negative trends for the cold seasons (November-March). It was found that these changes correspond to the decreasing contribution of “Northern meridional and Stationary anticyclone (Nm-Sa)” and “Northern meridional and East zonal (Nm-Ez)” circulation groups and to the increasing contribution of “West zonal and Southern meridional (Wz-Sm)” circulation groups, accordingly to the Dzerdzeevskii classification. In addition, it was found that the variation of precipitation has a step change point in 1980. For the warm seasons, the precipitation change at this point is associated with the reduced influence of “West zonal (Wz)”, “Northern meridional and Stationary anticyclone (Nm-Sa)” and “Northern meridional and Southern meridional (Nm-Sm)” circulation groups. For the cold seasons, a substantial increase of “Wz-Sm” and a decrease of “Nm-Sa”, “Nm-Ez” circulation groups are responsible for the precipitation change in the two time periods (1959-1980 and 1981-2014).