Weather@home East Asia: Causes of 2013 Heatwave

This project is aimed at assessing contribution of climate change to the summer 2013 heat wave over East Asia.

East Asia experienced a record-breaking heatwave in summer 2013. South Korea had its hottest summer nights and second hottest summer days since 1954 with summer mean daily minimum temperatures 2.2℃ warmer than the 1971-2000 climatology and the daily maximum temperatures 1.9℃ warmer.

The heat wave exerted devastating impacts on East Asian countries in terms of economy, health, and infrastructure. Particularly, in Korea, the heatwave increased electricity consumption beyond the forecast level, causing the Korean government to issue several power shortage warnings.

China also experienced one of the most severe heatwaves on record with respect to its geographical extent, duration and intensity. More than 300 weather stations exceeded a daily maximum temperature of 40℃. In Japan, daily maximum temperature records were broken at 143 sites in the west of the country.

Figure 1: Distribution of surface air temperature anomalies (℃) during July-August 2013. Anomalies are with respect to 1971-2000 mean and calculated from Climate Research Unit data.

The major question is whether frequency and intensity of East Asian extreme heat, like the observed 2013 event, has changed due to man-made greenhouse warming.

To answer this question, large ensemble simulations of regional climate models will be carried out for an East Asian domain for two worlds: (1) Real world condition for which the observed sea surface temperatures will be prescribed and (2) Counter-factual world condition for which we will use adjusted sea surface temperatures obtained by removing human-induced ocean warming patterns.

Weather@home East Asia will be extended for other years with extreme events including heavy rainfalls and droughts as well as exploring future conditions. This will allow scientists to better understand past changes and better predict future changes in weather extremes over East Asia under global warming.