The impact of global climate change on the characteristics of seasons in the Carpathian Basin

Similarly to many other regions, warming and extreme weather conditions (e.g. related to temperature and precipitation) are expected to increase due to the effects of climate change in the Carpathian Basin during the 21st century. Consequently, as a result of the clearly detectable warming, the number of frost days in winter decreases and the summer heat waves become more frequent. The transition between winter and summer tends to become shorter and the inter-annual variability is likely to increase. The precise definition of the transition periods between the two extremes of the annual temperature course is very important for several disciplines, e.g. building energy design, where outdoor temperature is a key input to determine the beginning and end of heating and cooling periods. The aim of this research is to examine the possible transformation of the four seasons characteristics of the Carpathian Basin in details using various specific climate indexes (e.g. monthly percentiles, daily temperature fluctuation time series) based on the data of regional climate model simulations taking into account different future scenarios. For this purpose, RCP4.5 and RCP8.5 scenarios are compared to historical runs, and simulated temperature data series are analyzed for the middle and end of the century.