Ledo dienų klimatinė charakteristika Baltijos šalyse

• Main Author: Šatas, Saulius
• Other Authors: Stankūnavičius, Gintautas
• Format: Bachelor Thesis
• Language: Lithuanian; English
• Published: Institutional Repository of Vilnius University 2017
• Subjects: Narva; North Atlantic
• Online Access: http://vu.lvb.lt/VU:ELABAETD35994672&prefLang=en_US

The main task of this work is to investigate the dynamic process of ice days and atmospheric circulation patterns in three Baltic countries during the winter seasons of 1926-2016. It is important to perform the statistical analysis of ice days, examine 500 hPa geopotential height anomalies over the North Atlantic and Europe and determine the backward trajectory of an air parcel. The day with the highest air temperature below freezing point (0°C) is called the ice day. For this research 9 stations were used from the Baltic States (Vilnius, Kaunas, Klaipėda, Kolka, Liepoja, Ryga, Kuusiku, Narva ir Tartu). These stations had the longest data of ice days. All stations were joint to three different groups based on their location. The first group of stations is maritime (Klaipėda, Liepoja, Kolka); the second – semi-continental (Kaunas, Riga, Kuusiku); the third – continental (Vilnius, Tartu, Narva). The 500 hPa geopotential height anomalies were used in order to find out the situation of mid-troposphere. Geopotential height anomalies where related to increased number of ice days in the selected region. The statistical analysis showed that the average number of ice days decreased in January, February and March months. In all stations the average number of ice days have barely changed. The research showed that winters with greater of amount of ice days are observed when positive 500 hPa geopotential height anomalies were over the North Atlantic, Scandinavia and the Barrets sea. The trajectory of an air parcel showed that during January in 1972 the cold air was moving from the north and north east while in 2010 from the east or south east.