The influence of Arctic and North Atlantic Oscillation on precipitation regime in Serbia

Abstract

The North Atlantic Oscillation (NAO) is the most significant large-scale mode of natural climate variability on the Northern Hhemisphere and Arctic Oscillation (AO) is its supplement. Both have large impacts on weather and climate in the North Atlantic region and surrounding continents including Europe. NAO and AO phases cause specific already defined changes in distribution of climate elements in wide area. The cross-correlation between daily precipitation data on stations in Serbia and NAO daily index plus AO daily index for the period 1951-2003 is analysed in this paper. Number of cross correlation coefficients have been calculated and the highest values were obtained for daily precipitation in Serbia with the AO index in winter, ranging from -0.44 to – 0.38. The analyses of trend for two periods 1961-2006 and 1980-2006 for the whole year and during winter months only, at 21 stations in Serbia have been performed, too. Very high positive trend for precipitation was obtained for many places in Serbia especially in Vojvodina. The results also indicate to non-homogeneities in the region and influence of NAO during winter.