Li Xiaoqiong, Ting Mingfang, Lee Dong Eun
Department of Earth and Environmental Sciences Columbia University New York NY USA.
Lamont-Doherty Earth Observatory Columbia University Palisades NY USA.
Geophys Res Lett. 2018 Jan 28;45(2):1001-1010. doi: 10.1002/2017GL076667. Epub 2018 Jan 24.
Anthropogenic aerosols are a major factor contributing to human-induced climate change, particularly over the densely populated Asian monsoon region. Understanding the physical processes controlling the aerosol-induced changes in monsoon rainfall is essential for reducing the uncertainties in the future projections of the hydrological cycle. Here we use multiple coupled and atmospheric general circulation models to explore the physical mechanisms for the aerosol-driven monsoon changes on different time scales. We show that anthropogenic aerosols induce an overall reduction in monsoon rainfall and circulation, which can be largely explained by the fast adjustments over land north of 20N. This fast response occurs before changes in sea surface temperature (SST), largely driven by aerosol-cloud interactions. However, aerosol-induced SST feedbacks (slow response) cause substantial changes in the monsoon meridional circulation over the oceanic regions. Both the land-ocean asymmetry and meridional temperature gradient are key factors in determining the overall monsoon circulation response.
人为气溶胶是导致人为气候变化的一个主要因素，在人口密集的亚洲季风区尤其如此。了解控制气溶胶引起的季风降雨变化的物理过程对于减少未来水文循环预测中的不确定性至关重要。在此，我们使用多个耦合和大气环流模型来探讨不同时间尺度上气溶胶驱动的季风变化的物理机制。我们表明，人为气溶胶导致季风降雨和环流总体减少，这在很大程度上可以用北纬20度以北陆地的快速调整来解释。这种快速响应发生在海面温度（SST）变化之前，主要由气溶胶-云相互作用驱动。然而，气溶胶引起的SST反馈（缓慢响应）导致海洋区域季风经向环流发生显著变化。陆海不对称和经向温度梯度都是决定季风环流总体响应的关键因素。
