Influence of atmospheric macroprocesses on the spatial distribution of spring precipitation within the territory of Ukraine

Abstract

The article presents the results of a comprehensive statistical study of the spatial distribution of spring precipitation in Ukraine and its relationship with the main low-frequency oscillations of the Northern Hemisphere. The research focuses on the monthly amount of rainfalls in March, April and May at 40 long-range stations of Ukraine that are evenly distributed throughout its territory, and the indices of North Atlantic (NAO) and North Sea-Caspian (NCP) fluctuations over a 45-year period (1962-2006). The use of multiyear data allowed for objective clusterization and division of the Ukrainian territory into regions with different types of weather observed in the event of precipitation, with each of them being physically substantiated. To ensure clarity, the article presents regional statistical models in the form of schematic maps of probable relationships between distribution of spring precipitation in Ukraine and the North Atlantic and Euro-Mediterranean macroprocesses. In order to forecast the monthly rainfall in March, it is advisable to take into account the state of the North Atlantic fluctuations. The response of this fluctuation was found within Chernivtsi, Vinnytsia, Cherkasy, Kyiv Regions, northern part of Odesa Region, western districts of Chernihiv Region and southern part of Zhytomyr Region. In the western regions of Ukraine, as well as in Vinnytsia, Kyiv, Zhytomyr and Chernihiv Regions, the formation of precipitation in April depends on the state of both NAO and NCP; in the rest of Ukraine – only of NCP. The 90% probability linear statistical relationship between precipitation in May and the main climatic signals of the Northern Hemisphere under study was not found only in some northern regions of Ukraine, namely: Kyiv, Chernihiv, Sumy Regions and central (Poltava and northern part of Cherkasy Region) part of Ukraine. A study of the influence of North Atlantic and Euro-Mediterranean macroprocesses on the distribution of monthly rainfall in Ukraine, conducted using a statistical approach, shows its ambiguity during different spring months and within different regions of Ukraine, and requires further research to solve the general scientific problem – study of climate-conditioned natural resources required to ensure sustainable socio-economic development of Ukraine under conditions of global climate change.

Keywords

• climate
• cluster analysis
• correlation coefficient
• long-range low-frequency oscillations
• atmospheric circulation