Analysis of extreme temperature events in Central Europe related to high pressure blocking situations in 2001–2011
Porebska, Magdalena; Zdunek, Malgorzata
This paper presents the relationship between occurrences of extreme temperature events in Central Europe and high pressure blocking situations during the 2001?2011 period. The diagnosis of high-pressure blocking situations is based on data from the ERA-Interim reanalysis project (DEE et al., 2011). Geopotential height fields at 500 hPa, with a horizontal resolution of 0.75 · 0.75 , taken at 00 UTC every day were used. For detection of extreme temperature events (ETE), we used daily maximum temperature records available in GSOD datasets from the U.S. National Climatic Data Center. The scope of this study includes an analysis of data originating from 30 surface stations located in Central Europe. The high-pressure blocking detection algorithm was based on the method proposed by SCHALGE et al. (2011). Temperature anomalies were divided into cold waves and heat waves. Blocking situations occurring in the Euro-Atlantic region were classified by their position with respect to the area of Central Europe. This classification is intended to reflect the most probable direction of the flow and the possible impact of the blocking. Results of research have shown a coincidence in time between blocking situations and extreme temperature events. Cold and heat waves were often associated with occurrences of high pressure blocking situations over the Atlantic Ocean and Eastern Europe, respectively. Furthermore, blocking highs lasting more than 5 days coincided more frequently with ETE than those shorter than 5 days. However, the large number of short-lasting blocking situations means that they often coincide with ETE. The presented results enhance the understanding of extreme temperature anomalies and their causes.