Numerical simulations are performed to investigate the radiative and cloud microphysical effects (direct and indirect effects respectively) of the Saharan dust aerosols and the subsequent perturbations of the radiation budget over the tropical East Atlantic Ocean. Simulations are conducted for July 1–31, 2010 over three two-way nested domains covering 0–25°N, 30–60°W using the Weather Research and Forecasting model coupled with Chemistry module (WRF-Chem-V3.6.1). Simulations of the dust direct effect over the outermost domain suggest that the dust-induced lower level heating increases the stability of the lower troposphere and reduces the cloud cover (up to 9%) underneath the maximum dust layer. Once the direct and indirect effects are considered together, dust particles act as cloud condensation nuclei and produce smaller sized cloud droplets. Overall, for the innermost domain, the mean cloud droplet radius becomes ~14% smaller in the presence of dust (12.4 μm and 10.7 μm in dust-free and dust-laden conditions respectively). Contrary to the direct effect, the coupled direct and indirect effects of dust not only reduces (up to 17%) the cloud cover below the maximum dust layer but also enhances (up to 9%) the cloud cover above the dust layers. The direct radiative forcing of dust excluding (including) cloud feedback are −13.66 (−4.83) and −11.25 (−1.22) W/m² at the surface and at the top of the atmosphere, respectively. Coupled direct and indirect effects of dust result in the net radiative forcing of dust to −8.14 and −5.03 W/m² at the surface and at the top of the atmosphere, respectively.

进行了数值模拟，以研究撒哈拉尘埃气溶胶的辐射和云微物理效应（分别为直接和间接效应），以及随后对热带东大西洋辐射预算的扰动。使用天气研究和预报模型结合化学模块（WRF-Chem-V3.6.1），于2010年7月1日至31日对三个双向嵌套域进行了模拟，两个嵌套域分别覆盖0-25°N，30-60°W。对最外层尘埃直接作用的模拟表明，由尘埃引起的较低水平的加热增加了对流层下部的稳定性，并减少了最大尘埃层下面的云量（高达9％）。一旦将直接和间接影响综合考虑，尘埃颗粒将充当云凝结核并产生较小尺寸的云滴。总体而言，对于最里面的区域，在有灰尘的情况下，平均云滴半径变小了约14％（在无尘和充满尘埃的条件下，分别为12.4μm和10.7μm）。与直接效应相反，粉尘的直接和间接耦合效应不仅减少（最多达17％）最大尘埃层以下的云量，而且增强（最多达9％）尘埃层以上的云量。除（包括）云反馈外，粉尘的直接辐射强迫为−13.66（−4.83）和−11.25（−1.22）W / m 灰尘的直接和间接耦合效应不仅会减少（最多达17％）最大灰尘层以下的云层，而且还会提高（最多达9％）灰尘层以上的云层。除（包括）云反馈外，粉尘的直接辐射强迫为−13.66（−4.83）和−11.25（−1.22）W / m 灰尘的直接和间接耦合效应不仅会减少（最多达17％）最大灰尘层以下的云层，而且还会提高（最多达9％）灰尘层以上的云层。除（包括）云反馈外，粉尘的直接辐射强迫为−13.66（−4.83）和−11.25（−1.22）W / m²分别在大气的表面和顶部。尘埃的直接和间接作用相结合，导致尘埃在大气表面和顶部的净辐射强迫分别为-8.14和-5.03 W / m ²。