Spatial Peculiarities of the NAO Impact on Air Temperature and Precipitation Field in 1950–2000

The research analyses spatial peculiarities of the North Atlantic Oscillation (NAO) impact on air temperature and precipitation amount in Lithuania in the context of Europe from 1950 through winter 2000 (December–March). It also discusses the dynamics of NAO-1, NAO-2 and NAO-3 indices, as well as correlation between them. The study is based on mean monthly NAO index values, air temperature and precipitation amount reported from eight meteorological stations (MS) in Lithuania. It was established that fluctuations in winter air temperature in Lithuania positively correlate with fluctuations in NAO indices (as in almost the entire Europe). The analysis of winter thermal conditions in the period of extreme NAO index values (|I| > ± 1.5σ) in Lithuania revealed that usually (75–88%) the periods of a negative NAO phase coincide with negative temperature anomalies, while those of a positive NAO phase – with positive temperature anomalies. Precipitation in Lithuania (as in the whole Europe), unlike air temperature, is not so closely associated with atmospheric circulation. The correlation between NAO indices and precipitation amount in Lithuania is statistically significant only for individual winter months.