Season-dependent warming characteristics observed at 12 stations in South Korea over the recent 100 years

A number of studies on the surface warming in the Korean Peninsula reported that there has been a notable increasing trend of surface air temperatures over the past several decades. Here, by analysing long-term surface air temperature data at 12 stations in South Korea that have records longer than 60 years, the authors show that the warming of spring and autumn temperatures is characterized by quasi-linear increases with time whereas the warming in winter and summer is characterized by one or two abrupt jumps. Change-point analysis of the seasonal-mean temperature time series shows that abrupt jumps in winter temperatures occurred in the late 1940s and late 1980s, while the jump in summer temperatures occurred in 1994 at most stations. The shape of the frequency distribution of the daily-mean temperature anomalies at all stations shifts to the warmer side after the jumps for both winter and summer. This shift in turn results in the decrease of cold extremes in winter and the increase of warm extremes in summer at all stations. Our results indicate that recent temperature records in South Korea are characterized by the two different types of warming according to seasons.