Emission scenario dependency of precipitation on global warming

根据MIROC3.2大气-海洋环流耦合模式，在温室气体浓度和气溶胶排放较大的排放情景下，21世纪气候预估中每1K全球变暖的降水敏感性较小。我们通过在高排放情景和低排放情景下进行单独的强迫运行来检验降水对排放情景敏感性的原因。发现对排放情景的依赖主要是由于不同排放情景间黑碳和有机碳气溶胶强迫的差异造成的，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运行中较大的降水敏感性（温度每冷却1K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.