ANOMALIES OF CYCLONIC ACTIVITY IN THE BLACK SEA – MEDITERRANEAN REGION AND THE NORTHERN HEMISPHERE TELECONNECTION PATTERNS

Abstract

For long-term climate prediction, rational use of natural resources, and strategic planning in the Black Sea–Mediterranean region, it is necessary to take into account the patterns of interannual-interdecadal variability of cyclonic activity associated with climate patterns not only in the North Atlantic but also in the entire hemisphere. The paper analyzes the spatiotemporal features of the frequency and average trajectories of cyclones in the Black Sea Mediterranean region against the background of the Atlantic-European region in the opposite phases of the main climatic oscillations in the Northern Hemisphere. Cyclones were identified using 6-hourly NCEP/NCAR reanalysis data on sea level pressure and two independent methodologies. The following main conclusions have been obtained. The Mediterranean and Western Mediterranean oscillations, as processes of regional transformation of the larger-scale oscillations in the Atlantic-European region, can serve as potential predictors for the exit regions of the southern (Mediterranean) cyclones. In the negative phases, cyclonic activity increases in the west or in the center of the Black Sea Mediterranean region. In the winter-spring period, during the negative phases of the Arctic, North Atlantic, and East Atlantic Oscillations, the cyclone trajectories shift to the south, affecting the Black Sea–Mediterranean region. Among the blocking oscillations, the negative phase of the East Atlantic/Western Russia pattern is characterized by an increase in the frequency of cyclones in the center of the Mediterranean region, while in the negative phases of the Scandinavia and Polar/Eurasia patterns, cyclonic activity is reduced in the west and east of the Mediterranean. Climate patterns that characterize the position and intensity of the Pacific jet stream are manifested in the cyclonic activity of the Black Sea Mediterranean region mainly with negative correlation: the Tropical/Northern Hemisphere and the West Pacific patterns in winter, the Pacific/North American pattern in spring, and the East Pacific-North Pacific pattern in autumn. The influence of climate oscillations determined by sea surface temperature can modulate the interannual climate patterns of the Atlantic-European region in spring. The frequency of cyclones in the Black Sea–Mediterranean region increases during La Niña and during the negative phases of the Atlantic Multidecadal and Pacific Decadal Oscillations. The revealed manifestations of 15 climate patterns form the basis for further research into physical processes of the regional climate anomalies.