Relationship between Eurasian large-scale patterns and regional climate variability over the Black and Baltic Seas

• Main Authors: Stankūnavičius, Gintautas, Basharin, Dmitry, Pupienis, Donatas
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2012
• Subjects: North-Atlantic oscillation; long-term variability; atmospheric circulation; surface-temperature; precipitation pattern; decadal variations; Europe; winter; trends; nao; Boreal Environment Research; North Atlantic; North Atlantic oscillation
• Online Access: http://vu.lvb.lt/VU:ELABAPDB4604586&prefLang=en_US

Using a NCEP/NCAR Reanalysis dataset and the empirical orthogonal function (EOF) analysis approach we studied interannual to decadal variabilities of the sea-level air pressure (SLP) and the surface air temperature (SAT) fields over Eurasiaduring the 2nd part of the 20th century. Our results agree with those of the previous studies, which conclude that Eurasian trends are the result of storm-path changes driven by the interdecadal behaviour of the NAO-like meridional dipole pattern in the Atlantic. On interannual and decadal time scales, significant synchronous correlations between correspondent modes of SAT and SLP EOF patterns were found. This fact suggests that there is a strong and stable Eurasian interrelationship between SAT and SLP large-scale fields which affects the local climate of two sub-regions: the Black and Baltic Seas. The climate variability in these sub-regions was studied in terms of Eurasian large-scale surface-temperature and air-pressure patterns responses. We concluded that the sub-regional climate variability substantially differs over the Black and Baltic Seas, and depends on different Eurasian large-scale patterns. We showed that the Baltic Sea region is influenced by the patterns arising primary from NAO-like meridional dipole, as well as Scandinavian patterns, while the Black Sea’s SAT/SLP variability is influenced mainly by the second mode EOF (eastern Atlantic) and large scale tropospheric wave structures.