Abstract:

Based on the observation of daily temperature data and 30 models data provided by Coupled Model Intercomparison Project (CMIP5), five extreme temperature indices including mean maximum temperature (TXAV), mean minimum temperature (TNAV), heat wave duration index (HWDI), frost days (FD) and warm nights (TNF90) have been calculated to evaluate simulation capability of each model in terms of spatial field in climate state and the trend of extreme temperature in China. Results show that most models can better reflect the spatial pattern of extreme temperature indices in climate state. The spatial pattern of TNAV, TAXV and FD can be better simulated, as the correlation coefficient of most models are more than 0.9, and there are good consistency between models. TNF90 and HWDI are poorly captured by models, as the correlation coefficient are lower than 0.7 and there are large differences between models. Models also simulate the same trend change of average extreme temperature index at national scale as the observation, but their most simulation strength of trend are weak. Compared with spatial pattern in climate state, the models simulation of trend spatial pattern for extreme temperature are not good. Thereinto, TNAV is relatively well simulated, the correlation coefficient of a third of models are larger than 0.6. The correlation coefficient for other indices are lower than 0.6. The models simulation ability ranks of space and time are in good consistency. Based on the comprehensive space-time simulation ability, the top 5 models are MPI-ESM-P, CMCC-CM, IPSL-CM5A-LR, CESM1-CAM5 and ACCESS1-3. The best multi-models ensemble (BMME) can reduce the biases and narrow the biases areas.

Key words: CMIP5, extreme temperature, trend, best multi-models ensemble