Emission scenario dependency of precipitation on global warming

根据MIROC3.2大气-海洋耦合大气环流模式，在温室气体浓度和气溶胶排放较大的排放情景中，21世纪气候预测中每1K全球变暖的降水敏感性较小。我们通过在高排放和低排放情景下进行单独的强迫运行，研究了降水对排放情景敏感的原因。研究发现，对排放情景的依赖主要是由于排放情景之间的黑碳和有机碳气溶胶强迫的差异造成的，并且降水对碳气溶胶比混合良好的温室气体更敏感。我们还研究了碳气溶胶过程中较大的降水敏感性(每1K降温一次降水减少幅度较大)的原因。

The precipitation sensitivity per 1K of global warming in 21st century climate projections is smaller in an emission scenario with larger greenhouse gas concentrations and aerosol emissions, according to the MIROC3.2 coupled atmosphere-ocean general circulation model. We examined the reasons for the precipitation sensitivity to emission scenarios by performing separated individual forcing runs under high and low emission scenarios. It was found that the dependency on emission scenario is mainly caused by differences in black and organic carbon aerosol forcing between the emission scenarios and that the precipitation is more sensitive to carbon aerosols than well-mixed greenhouse gases. We also investigated the reason for the larger precipitation sensitivity (larger magnitude of precipitation decrease per 1K cooling of temperature) in the carbon aerosol runs.