Spatiotemporal distribution of the climatological fronts over Europe in the modern climate period

Abstract

The geographical position of the Arctic front and two branches of the Polar front over Europe was determined during the period 1995–2015 using calculated grid fields of the thermal frontal parameter in the troposphere layer of 850–700 hPa. It was revealed that the geographical position of climatological fronts changed both in the cold and warm periods of the year in comparison with climate data. The most recent standard reference period of 1961–1990 recommended by WMO (WMO, 2017) was used for comparison. It is shown that in January there was a shift of the northern and southern branches of the Polar front to the north compared to the reference climate period, and in July the convergence of both branches of the Polar front in the middle latitudes was observed. The Arctic front was characterized by a northern location compared to the climate in both January and July. It is revealed that the main areas of frontogenesis in the cold period of the year were the sea surface, namely, the southern regions of the Norwegian Sea, the central part of the Baltic Sea, and the western half of the Mediterranean Sea. In the summer, more active atmospheric fronts were over the continent in the area of the mountain systems such as the south of the Scandinavian mountains, the north of the Alps and Pyrenees, the Urals, and the lower Volga region. The Arctic front intensified over the Barents and Norwegian Seas in all seasons of the year.