Vėjo krypties ir greičio kaita Lietuvoje 1971–2010 metais

• Published in: Geografija
• Main Authors: Strolytė, Skirmantė, Rimkus, Egidijus
• Format: Article in Journal/Newspaper
• Language: Lithuanian; English
• Published: 2012
• Subjects: Wind direction; Wind speed; NAO; AO; Arctic; North Atlantic; North Atlantic oscillation
• Online Access: http://vu.lvb.lt/VU:ELABAPDB4720325&prefLang=en_US

The main task of this study is assessment of the wind regime and its changes in Lithuania during period from 1971 till 2010 as well as evaluation of relationships between the wind parameters (direction and speed) and large scale atmospheric circulation indexes (NAO (North Atlantic Oscillation) and (AO) Arctic Oscillation). Monthly wind speed and direction data from 8 meteorological stations were analyzed in this research. The wind direction recurrence tendencies in the territory of Lithuania differ a lot. The particularly profound shift in wind direction regime was found in Utena and Klaipėda MS. The largest changes were recorded in the winter. Significant increase in frequency of south-west and north-east winds was observed in the western part of Lithuania, while reoccurrence of south-west winds decreased in the rest of the territory. Almost in the whole territory of Lithuania increase of eastern winds was observed. The mean annual wind speed declined in almost whole Lithuanian territory during investigation period. The strongest negative changes were observed in the eastern part of Lithuania. Wind speed from all directions decreased by 0.4–0.9 m/s in Utena MS. Weakening of wind from west and southwest was common for the large part of Lithuania. Measured changes in winter were more significant than in summer. It was determined that the strongest influence of NAO and AO on the wind regime occurs in winter and in case of AO also in autumn. The influence of NAO and AO on wind direction is more significant. According to data from all meteorological stations, there were observed increase in the frequency of western winds and decrease in the frequency of eastern winds in strongly positive phase of NAO/AO values in winter. Also, increase of mean annual wind speed as well as increase in wind speed from western and southern directions during the high NAO/AO index values were determined.