Šiaurės Atlanto osciliacijos poveikis Lietuvos klimatui

• Main Authors: Mickevičius, Vytenis, Bukantis, Arūnas
• Format: Article in Journal/Newspaper
• Language: Lithuanian; English
• Published: 2013
• Subjects: NAO; Air temperature; Precipitation; Snow cover duration; SA; North Atlantic
• Online Access: http://vu.lvb.lt/VU:ELABAPDB4904445&prefLang=en_US

The paper analyzes North Atlantic oscilliation (NAO) effects and its tendency on mean air temperature, precipitation, hygrotermic index (HTI) and snow cover duration in Lithuania in 1961–2010. Also the intensity of NAO impact was analysed depending on solar activity (SA). Data from Vilnius and Klaipėda meteorological stations were analysed in this study. The strongest impact of NAO on mean air temperature was noticed in winter, while the weakest in summer. Statistically insignificant NAO impact is in spring and autumn. Summer and winter precipitation are strongly influenced by NAO, but NAO impact is weak in autumn. It is interesting to note that statistically significant reverse relationship between NAO and precipitation in Vilnius is in spring, while no such relationship exists in Klaipėda. Snow cover duration in Lithuania is strongly influenced by NAO. In negative NAO phase snow cover lasts at longest, while in positive at shortest. The strongest impact of NAO is on HTI in winter. The intensity of NAO impact is not constant. In 1961–2010 the relationship between mean air temperature in autumn and NAO had been changing (getting weaker) the most significantly. The impact of NAO on mean air temperature in spring and on precipitation in summer was getting stronger. The changes of the NAO impact were not statistically significant in other seasons. The strength of NAO impact differs in various periods of SA. The strongest impact of SA is in spring. It was established a strong positive link between mean air temperature and NAO in SA maximum years, while the mean air temperature correlate reverse with NAO in SA minimum years. It should be noted that also in winter in SA maximum years the impact of NAO on air temperature and precipitation is stronger.