| ABSTRACT | Some of the most important modes of atmospheric variability characterizing the Northern Hemisphere are the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, the East Atlantic/West Russia pattern (EA/WR), and the Pacific/North American pattern. The EA/WR pattern consists of four main anomaly centers and affects Eurasia throughout year. In this study, the influence of the EA/WR pattern on precipitation over Mediterranean and Serbia is examined.
The monthly precipitation dataset for the period 1950 to 2013 with a 2.5×2.5° spatial resolution are obtained from the Global Precipitation Climatology Centre (GPCC). We used precipitation data from 1961 to 2016 for 15 stations, that are operated by the Republic Hydrometeorological Service of Serbia (http://www.hidmet.gov.rs/).
Precipitation anomalies have been explored in relation to strong positive and negative phases of the EA/WR pattern. For the negative EA/WR phase, positive precipitation anomalies prevail over Mediterranean in January, March, June and July. Negative precipitation anomalies are distributed over Central and Eastern Mediterranean in February, April, May, August, September and December. A more complicated spatial distribution exists October. Strong positive anomalies are found over Western Mediterranean in February, April and December.
For the strong positive EA/WR phase, positive precipitation anomalies are pronounced over Western Mediterranean in January. Positive precipitation anomalies prevail over Mediterranean in March, June and August, over central Mediterranean in April, September and November. Negative precipitation anomalies are pronounced in February, over central Mediterranean in October and over Eastern Mediterranean in November and December.
The precipitation anomalies associated with the strong negative (positive) phase of the EA/WR pattern reflect above (below) average precipitation over Serbia.
In addition, a spatial distribution of precipitation anomalies is examined for all combinations of positive and negative phases of the EA/WR pattern and NAO or EA pattern. We find that the effect of the EA/WR pattern on precipitation changes is not dependent of the NAO or EA phase over Serbia. |