Positive relationship between liquid cloud droplet effective radius and aerosol optical depth over Eastern China from satellite data
Positive relationship between liquid cloud droplet effective radius and aerosol optical depth over Eastern China from satellite data
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DOI：
10.1016/j.atmosenv.2013.08.024
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发表时间：
2014-02
影响因子：
5
通讯作者：
Jinping Tang;Pucai C. Wang;L. Mickley;X. Xia;H. Liao;X. Yue;Li Sun;Junrong Xia
中科院分区：
文献类型：
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作者：
Jinping Tang;Pucai C. Wang;L. Mickley;X. Xia;H. Liao;X. Yue;Li Sun;Junrong Xia
利用MODIS对2003-2012年中国东部7个子区域的水云有效半径（CER）与气溶胶光学深度（AOD）的相关性进行了研究。水相云定义为云顶压力大于800hpa。在东海和南海，AOD < 0.3的格点AOD与CER之间存在显著的负相关系数（r= - 0.79 ~ - 0.94）。然而，AOD为bb0 0.3的细胞计算出正相关（r= 0.01-0.91）。相比之下，中国东部大陆和黄海的正相关显著（r= 0.67-0.95）。对华北平原的进一步分析表明，风速和相对湿度的变化可能解释了这种正相关。南风携带高水平的污染物和丰富的水汽，导致华北平原AOD和CER同时增加，而北风携带来自高纬度的干燥清洁空气，导致AOD和CER减少。这两个过程都促成了中国东部AOD和CER的正相关，表明在研究气溶胶与云的相互作用时需要考虑背景天气条件的影响。
Correlations between water cloud effective radius (CER) and aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) are examined over seven sub-regions in Eastern China for 2003–2012. Water phase cloud is defined as having a cloud top pressure greater than 800 hPa. Significant negative correlation coefficients (r= −0.79 ∼ −0.94) between AOD and CER are derived over the East Sea and the South China Sea for grid cells with AOD < 0.3. However, positive correlations (r= 0.01–0.91) are calculated for cells with AOD > 0.3. In contrast, significant positive correlations (r= 0.67–0.95) are derived over the Eastern China mainland and Yellow Sea. Further analysis for North China Plain shows that variations in wind speed and relative humidity may account for such positive correlations. Southerly winds carry high levels of pollutants and abundant water vapor, resulting in coincident increases in both AOD and CER in North China Plain, while the northerly winds transport dry and clean air from high latitudes, leading to decreases in AOD and CER. Both processes contribute to the positive correlations between AOD and CER over Eastern China, suggesting that the influence of background weather conditions need to be considered when studying the interactions between aerosol and cloud.