Multi-Model Ensemble Prediction of Extreme Temperature Indices in China
Using the results of IPCC-AR4 simulations, extreme temperature trends in China are analyzed under three different emissions scenarios--SRES A 2, SRES A1B, and SRES B1. Results show that extreme temperature indices exhibit consistent trends throughout China. The indices of frost days (FD) and extreme temperature range (ETR) decrease, while increases occur for growing season length ( GSL), warm nights ( TN90) and heat wave duration index (HWDI). In the high emissions scenario (A2), index trends show the largest changes, and have the lowest amount of change in the low emissions scenario (B1). Changes in the five indices are more substantial in SRES A1B than in SRES A2 before the year 2075, in contrast to variations after that year. Among the extreme temperature indices, HWDI and 77V90 have the largest increases. For SRES A2, the changes in heat wave duration index and warm nights are 90.2d/100a and 44.3%/100a respectively, and the frost days and growing season length have the second largest changes, of - 42 days per decade and 28.1 days per decade, respectively, with the least change in ETR, which decreased 1.7℃ per decade. Zonal means indicate that during the period of 2021 ~ 2050, the smallest change in HWDI is an increase of 13.6 days in SRES B1, where ETR shows its largest change of -0.4℃. The most significant variations in FD, GSL, HWDI and 7W90 are - 16.8 days, 17.2 days, 16.7 days and 14.7%, respectively, in the emissions scenarios of A1B, in which ETR has the smallest change of - 0.18℃. In the late 21st century (2071 to 2100), HWDI change is greatest with 72.8 days, but ETR has the smallest change of - 1.3℃, while other indices such as FD, GSL and TN90 have similar changes as in the high emissions scenario. Except for the index of growing season length, the spatial distributions of the other four indices' trends are almost the same throughout the whole country, with variability tending to increase gradually from northern to southern China. There are more marked changes in northwest China than northeast China for indices of FD, ETR and HWDI, as compared to TN90 which has larger changes in southwest and southern China.
Extreme temperature indicesEmissions scenariosModel ensemble
NETL
NSTL
万方数据
维普
