Climate fluctuations in the Czech Republic during the period 1961-2005

This article addresses climatic fluctuations in the Czech Republic in the period 1961-2005. Oil the basis of data collected at 23 climatological Stations, the fluctuations ill Monthly. seasonal. and annual series of selected climate variables. homogenized by means of Standard Normal Homogeneity Test (SNHT) (after Alexandersson), Lire analysed. With almost unchanging temperature continentality expressed by the Gorczynski index, the annual series of mean air temperature, maximum and minimum temperature, daily temperature range. and Sunshine duration all exhibit a rising linear trend, in contrast to dropping trends in relative air humidity. number of days with snow cover, and mean wind speed. There are no pronounced changes in precipitation totals, although their distribution over the Course of the year becomes more regular in term of the Markham seasonality index. Temperature trends, with the exception of autumn. show a clear enhancement since the 1980s: statistically significant rising trends occur for only spring,summer and the year in a good agreement with the Northern Hemisphere series. Linkage to fluctuation in the North Atlantic Oscillation Index (NAOI) is best expressed by the Czech temperature characteristics for January, February, and winter (in similar fashion to that for the number of days with snow cover). which call be ascribed to intensification of the western ariflow over Central Europe. Oil the other hand. link-age to NAOI for precipitation is essentially weaker, because of the role of synoptic processes in influencing the occurrence of precipitation at the regional scale. Better relationships for temperature variables and wind speed are obtained if the Central European Zonal Index (CEZI) is used instead of NAOI as an indicator Of circulation patterns in Central Europe. Copyright (c) 2008 Royal Meteorological Society