In order to protect the lives and property of citizens, the central and local governments are responding by enacting municipal ordinances and regulations as the frequency of extreme weather conditions due to climate change increases and intensity increases gradually. Accordingly, the basic contents and strategies of domestic and foreign policies to cope with cold and heat waves were reviewed, referring to measures suitable for application to the Daegu metropolitan area. In addition, it is intended to provide a policy alternative to Daegu metropolitan area to minimize damage from extreme weather by identifying the current status, characteristics, and future prospects of extreme weather in Daegu metropolitan area. Since the damage caused by the cold wave in Daegu area is not as great as that of other regions, it is urgent to come up with cold wave measures for the health and transportation sectors, and to come up with measures against the heat wave as the damage caused by the heat wave is the most serious in the country. Also we will identify spatial characteristics so that the districts and counties with high vulnerability to extreme weather can be identified and implemented first, and present civic life-oriented facilities and civic action guidelines to overcome cold and heat waves.

The purpose of this study is to characterize the synoptic climatic patterns of extreme humansensible temperature (HST) events in Jeju Island, Korea under a subtropical climate condition as well as to examine their teleconnections with the large-scale climate systems. According to the extreme case analysis of the recent 30 years (1988-2017) data sets, the maximum daily average HST in the coastal areas of Jeju Island can rise up to about 40°C in mid-summer and even up to about 48°C during mid-daytime. These extreme HST events occur when the expansion of subtropical Pacific high pressure toward East Asia as well as the poleward shift of the Changma front provides hot and humid conditions over Jeju Island surrounded by seas, particularly in La Niña years with a positive (+) Arctic Oscillation mode. In contrast, the intensified western high and eastern low dipole pressure pattern in mid-winter, which accompanies the downward shear of upper tropospheric cold air toward the southern region of the Korean Peninsula under a negative (-) Arctic Oscillation mode, provides favorable conditions for frequent low HST extreme events. These conditions can lower daily average HST as much as -10°C in the coastal region of Jeju Island, and lower nighttime HST by -25°C on the peak areas of Mt. Halla due to wind chill effects. These findings will be used as a base for establishing prediction and warming systems of extreme HST events on Jeju Island, which is needed to mitigate the damage to the lives of Jeju residents and tourists under climate change.

Regional climate simulations for the CORDEX East Asia domain were conducted between 1981 and 2100 using five models to project future climate change based on RCP2.6, 4.5, 6.0, and 8.5 scenarios. By using the ensemble mean of five model results, future changes in climate zones and four extreme temperature events of South Korea were investigated according to Köppen-Trewartha’s classification criteria. The four temporal periods of historical (1981-2005), early future (2021-2040), middle future (2041-2070), and late future (2071-2100) were defined to examine future changes. The analysis domain was divided into 230 administrative districts of South Korea. In historical (1981-2005) period, the subtropical zones are only dominant in the southern coastal regions and Jeju island, while those tend to expand in the future periods. Depending on the RCP scenarios, the more radiative forcing results in the larger subtropical zone over South Korea in the future. The expansion of the subtropical zone in metropolitan areas is more evident than that in rural areas. In addition, the enlargement of the subtropical zone in coastal regions is more prominent than that of in inland regions. Particularly, the subtropical climate zone for the late future period of RCP8.5 scenario is significantly dominant in most South Korea. All scenarios show that cold related extreme temperature events are expected to decrease and hot related extreme temperature events to increase in late future. This study can be utilized by administrative districts for the strategic plan of responses to future climate change.

We examined temporal and spatial structure of trends in precipitation-based and temperaturebased extreme indices simulated by the Regional Model Program of Global/Regional Integrated Model System (GRIMs-RMP). The extreme indices were selected to consider the frequency, intensity, and persistence of extreme events. During the Last 30 years from 1979 to 2008, the model reasonably have simulated the temporal and spatial pattern of the trend. Although overestimation of minimum temperature and underestimation of maximum temperature occured, the regional climate model captured observed direction and magnitude well in the indices based on temperature. The indices related to rainfall tended to be overestimated over East Asia except for Korea and Japan. However, the trend showd agreement with observation. the results allow us to be optimistic about the RCM ability in the simulation of important extreme event of precipitation and surface temperature in East Asia. This type of study can also provide meaningful climate statistics and insight into climate change impact study.