资源环境科技发展态势分析平台

This study evaluates the National Aeronautics Space Administration (NASA) Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) dataset that provides statistically downscaled CMIP5 historical and future climate projections (precipitation and temperature), at high spatial (25 km) and temporal (daily) resolutions. The study is performed over Southeast Asia for the historical period 1976-2005 and compared against gridded observations on daily scales. Future climate change is assessed over the future time slices, 2020-2050 and 2070-2099, under two Representative Concentration Pathways (RCP) scenarios 4.5 and 8.5 with respect to 1976-2005. The future climate projections indicate that surface temperatures over Southeast Asia are likely to increase by more than 3.5 A degrees C by the end of the century. As to precipitation, both the mean and extreme rainfall are likely to increase but the biases in the historical simulations could contribute to larger uncertainties in the estimates of rainfall projections. Findings of the study indicate that NEX-GDDP are in good agreement with observations over the historical period only on monthly scales and that they do not capture the observed statistics on daily scales which suggests that these data need a deeper scrutiny on daily scales, especially when used for impacts studies.