The Decadal-Multidecadal Changes of Extreme Air Temperature in the Black Sea Region

Abstract

The decadal-multidecadal changes of extreme air temperature characteristics during winter and summer in the Black Sea region are studied in the paper. The 5th and 95th percentiles of intra-seasonal daily temperature anomalies and number of days with air temperature below the 5th and above the 95th percentile were used to describe moderate extremes. The average daily air temperature data from 13 hydrometeorological stations in 1950–2014 and from several stations in 1900–2005 were analyzed.Pacific Decadal oscillation (PDO) and the Atlantic Multidecadal oscillation (AMO) were considered as the main global processes in the ocean-atmosphere system responsible for regional climate change on decadal-multidecadal scale. The differences of extreme air temperature characteristics between positive and negative AMO and PDO phases are analyzed in the paper. It is found that the extreme winter air temperature anomalies are increased by about 2 °C during the positive PDO phase and negative AMO phase. The winter frequency of extreme low temperature is decreased by two times during the positive PDO phase and negative AMO phase. The summer changes of extreme temperature characteristics, associated with the PDO and AMO phases are insignificant.