Contributions of Radiative Factors to Enhanced Dryland Warming (Invited Presentation)

Enhanced near-surface atmospheric warming has occurred over East Asia in recent decades, especially in drylands. Although local factors have been confirmed to provide considerable contributions to this warming, such factors have not been sufficiently analyzed. In this study, we extracted the radiatively-forced temperature (RFT) associated with the built-up greenhouse gases (GHGs), aerosol emission and various other radiative forcing over East Asia, and found a close relationship between RFT and CO2. In addition, using climate model experiments, we explored the responses of temperature changes to black carbon (BC), CO2 and SO4, and found that the enhanced dryland warming induced by CO2 had the largest magnitude and was strengthened by the warming effect of BC. Moreover, the sensitivity of daily maximum and minimum temperature changes to BC, CO2 and SO4 was examined. It showed asymmetric responses of daily maximum and minimum temperature to radiative factors, which led to an obvious change of diurnal temperature range (DTR), especially in drylands. However, the obvious variability of daily maximum, minimum temperature in drylands do not appear in North America, which indicate the effects of radiative factors to DTR change have typical local effect and require more investigation.