Characteristics of Extreme Climate Sequences over Korea Using a Regional Climate Change Scenario

We investigate the characteristics and potential future change of extreme climate phenomena based on daily statistical properties. To assess the fine-scale climate change projection over Korea, an ECHO-G B2 scenario simulation has been dynamically downscaled by using the RegCM3 nesting system. Two sets of multi-decadal simulations are performed for the present day (1971-2000) and future climate (2021-2050). We analyze four categories of weather spells in terms of the sequences of dry/wet and frost/hot days from the nested domain simulation of 20 km grid spacing. In the validation of the reference scenario, the model shows a reasonable performance of reproducing both observed climatological and distinct characteristics of each spell. Regarding the projected extreme climate events, the results indicate not only a significant change in frequency and intensity, but also substantial change in the fine scale detail of the regional distribution of temperature-based as well as precipitation-based extreme events. A substantial increase of hot spells is found along with increasing of maximum temperature. Longer-period frost spells are projected to decrease, whereas relatively short-period frost spells are likely to increase due to breaks of long spells by greenhouse warming. Wet spells of long periods tend to be more frequent, showing a distinct variation across regions.