Liu L, Shawki D, Voulgarakis A, Kasoar M, Samset B H, Myhre G, Forster P M, Hodnebrog Ø, Sillmann J, Aalbergsjø S G, Boucher O, Faluvegi G, Iversen T, Kirkevåg A, Lamarque J-F, Olivié D, Richardson T, Shindell D, Takemura T
Department of Physics, Imperial College London, London, UK and Northwest Institute of Nuclear Technology, Xi'an, China.
Department of Physics, Imperial College London, London, UK.
J Clim. 2018 Jun 1;31(11):4429-4447. doi: 10.1175/JCLI-D-17-0439.1. Epub 2018 May 17.
Atmospheric aerosols such as sulfate and black carbon (BC) generate inhomogeneous radiative forcing and can affect precipitation in distinct ways compared to greenhouse gases (GHGs). Their regional effects on the atmospheric energy budget and circulation can be important for understanding and predicting global and regional precipitation changes, which act on top of the background GHG-induced hydrological changes. Under the framework of the Precipitation Driver Response Model Inter-comparison Project (PDRMIP), multiple models were used for the first time to simulate the influence of regional (Asian and European) sulfate and BC forcing on global and regional precipitation. The results show that, as in the case of global aerosol forcing, the global fast precipitation response to regional aerosol forcing scales with global atmospheric absorption, and the slow precipitation response scales with global surface temperature response. Asian sulphate aerosols appear to be a stronger driver of global temperature and precipitation change compared to European aerosols, but when the responses are normalised by unit radiative forcing or by aerosol burden change, the picture reverses, with European aerosols being more efficient in driving global change. The global apparent hydrological sensitivities of these regional forcing experiments are again consistent with those for corresponding global aerosol forcings found in the literature. However, the regional responses and regional apparent hydrological sensitivities do not align with the corresponding global values. Through a holistic approach involving analysis of the energy budget combined with exploring changes in atmospheric dynamics, we provide a framework for explaining the global and regional precipitation responses to regional aerosol forcing.
硫酸盐和黑碳（BC）等大气气溶胶会产生不均匀的辐射强迫，与温室气体（GHG）相比，它们对降水的影响方式有所不同。它们对大气能量收支和环流的区域影响对于理解和预测全球及区域降水变化至关重要，这些变化叠加在温室气体引起的背景水文变化之上。在降水驱动响应模型比对项目（PDRMIP）的框架下，首次使用多个模型来模拟区域（亚洲和欧洲）硫酸盐和黑碳强迫对全球和区域降水的影响。结果表明，与全球气溶胶强迫的情况一样，全球对区域气溶胶强迫的快速降水响应与全球大气吸收成正比，而缓慢降水响应与全球地表温度响应成正比。与欧洲气溶胶相比，亚洲硫酸盐气溶胶似乎是全球温度和降水变化的更强驱动因素，但当响应按单位辐射强迫或气溶胶负荷变化进行归一化时，情况则相反，欧洲气溶胶在驱动全球变化方面更有效。这些区域强迫实验的全球表观水文敏感性再次与文献中相应的全球气溶胶强迫的敏感性一致。然而，区域响应和区域表观水文敏感性与相应的全球值并不一致。通过一种综合方法，包括分析能量收支以及探索大气动力学变化，我们提供了一个框架来解释全球和区域降水对区域气溶胶强迫的响应。
