Zmiany intensywności wyżu syberyjskiego i ich wpływ na temperaturę powietrza w środkowej Syberii

Abstract

On the basis of daily data from Baseline Meteorological Data in Siberia, Version 5.0 for 5 stations located in central Siberia changes in the intensity of the Siberian High 1950-2008 and their impact on air temperature were examined. It was found that trends of the air pressure were negative in the centre of the Siberian High in the analysed period, particularly from the 1980s. The decrease in Siberian High intensity was correlated with an increase in temperature in the region. Using the average daily values of sea level pressure for the Asian sector of the Northern Hemisphere (reanalysis data), it was demonstrated that the occurrence of extremes in winter air temperature are strongly dependent on the Siberian High intensity and other macro-scale circulation patterns. Occurrence of the lowest values of temperature is accompanied by a strengthening of the Siberian High and by the negative phase of the Arctic Oscillation, while the highest values of air temperature in winter months are associated with negative pressure anomalies over the Northeastern Asia, which means a weakening of the Siberian High and intensifying of the influx of air masses from the west.