Multi-sensor quantification of aerosol-induced variability in warm clouds over eastern China
Multi-sensor quantification of aerosol-induced variability in warm clouds over eastern China
复制标题
多传感器量化中国东部暖云特性气溶胶引起的变化
DOI：
10.1016/j.atmosenv.2015.04.063
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发表时间：
2015-07-01
影响因子：
5
通讯作者：
Li, Xiaowen
中科院分区：
文献类型：
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作者：
Wang, Fu;Guo, Jianping;Li, Xiaowen
由于难以获得准确的气溶胶和云观测，气溶胶-云(AC)相互作用仍未确定。在这项研究中，我们利用MODIS/AQUA、CALIOP/CALIPSO和CPR/CLOUDSAT在2006年6月至2010年12月几乎同时进行的反演，量化了气溶胶对中国东部暖云的间接影响。地面PM10(直径小于或等于10微米的气溶胶粒子)的气溶胶的季节性与MODIS气溶胶光学厚度(AOD)估算的结果有显著差异。这一结果得到了CALIOP的低层气溶胶发生频率剖面的支持，表明CALIOP在AC相互作用中起着重要的作用。为了关注暖云，基本(顶部)高度超过7(10)公里的云层被排除在外。CALIOP和CPR的组合被用来根据AC混合状态确定以下六种情景中暖云相对于气溶胶的确切位置：1)纯气溶胶(AO)；2)纯云(CO)；3)单气溶胶层-单云层(SASC)；4)单气溶胶层-双云层(SADC)；5)双气溶胶层-单云层(DASC)；以及6)其他。气溶胶与云层垂直距离小于(大于)100m(700m)的个例被标记为混合(分离)，其余为不确定。结果表明，在SASC、SADC和DASC并置的AC重叠案例中，只有8.95%(7.53%)属于混合(分离和不确定)状态。在混合条件下，在中等气溶胶负荷(AOD)下，云滴有效半径(CDR)随AOD的增大而减小
Aerosol-cloud (AC) interactions remain uncharacterized due to difficulties in obtaining accurate aerosol and cloud observations. In this study, we quantified the aerosol indirect effects (AIE) on warm clouds over Eastern China based on near-simultaneous retrievals from MODIS/AQUA, CALIOP/CALIPSO, and CPR/CLOUDSAT between June 2006 and December 2010. The seasonality of aerosols from ground-based PM10 (aerosol particles with diameter of 10 mu M or less) significantly differed from that estimated using MODIS aerosol optical depth (AOD). This result was supported by the lower level frequency profile of aerosol occurrence from CALIOP, indicative of the significant role of CALIOP in the AC interaction. To focus on warm clouds, cloud layers with base (top) altitudes above 7 (10) km were excluded. The combination of CALIOP and CPR was applied to determine the exact position of warm clouds relative to aerosols out of the following six scenarios in terms of AC mixing states: 1) aerosol only (AO); 2) cloud only (CO); 3) single aerosol layer-single cloud layer (SASC); 4) single aerosol layer-double cloud layers (SADC); 5) double aerosol layers - single cloud layer (DASC); and 6) others. The cases with vertical distance between aerosol and cloud layer less (more) than 100 m (700 m) were marked mixed (separated), and the rest as uncertain. Results showed that only 8.95% (7.53%) belonged to the mixed (separated and uncertain) state among all of the collocated AC overlapping cases, including SASC, SADC, and DASC. Under mixed conditions, the cloud droplet effective radius (CDR) decreased with increasing AOD at moderate aerosol loading (AOD