Assessment of the changes in extreme vulnerability over East Asia due to global warming

A number of indices have been employed to describe weather extremes on the basis of climate regimes and public concerns. In this study, we combined these traditional indices into four groups according to whether they relate to warm (T-warm), cold (T-cold), wet (P-wet), or dry (P-dry) extremes. Analysis of the combined indices calculated for the daily temperatures and precipitation at 750 meteorological stations in Korea, China, and Japan for 1960s-2000s shows increasing trends in T-warm and P-dry events and decreasing trends in T-cold events in recent decades, particularly in the northern part of East Asia. A notable regional variation is an increase in the P-wet events in the Korean Peninsula. We applied the same analysis to a 200-year global climate model simulation for 1900-2099 using the National Center for Atmospheric Research-Community Climate System Model 3. During the 20th century, the changes in T-warm and T-cold calculated from the model data are largely consistent with those calculated from the observations, especially in northern East Asia. The model projections for the 21st century indicate statistically significant increasing T-warm and decreasing T-cold trends in extreme events over the region. Results obtained from historical archives and model simulations using our combined weather extreme indices suggest that northern East Asia will be subject to increased warm and dry extremes and the Korea Peninsula will experience more wet extremes.