Rajapakshe Chamara, Zhang Zhibo, Yorks John E, Yu Hongbin, Tan Qian, Meyer Kerry, Platnick Steven, Winker David M
Physics Department, UMBC, Baltimore, MD.
Joint Center for Earth System Technology, UMBC, Baltimore, MD.
Geophys Res Lett. 2017 Jun 12;Volume 44(Iss 11):5818-5825. doi: 10.1002/2017gl073559.
From June to October, low-level clouds in the Southeast (SE) Atlantic often underlie seasonal aerosol layers transported from African continent. Previously, the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) 532 nm lidar observations have been used to estimate the relative vertical location of the above-cloud aerosols (ACA) to the underlying clouds. Here, we show new observations from NASA's Cloud-Aerosol Transport System (CATS) lidar. Two seasons of CATS 1064 nm observations reveal that the bottom of the ACA layer is much lower than previously estimated based on CALIPSO 532nm observations. For about 60% of CATS nighttime ACA scenes, the aerosol layer base is within 360 m distance to the top of the underlying cloud. Our results are important for future studies of the microphysical indirect and semi-direct effects of ACA in the SE Atlantic region.
6月至10月期间，东南大西洋的低层云常常位于从非洲大陆输送来的季节性气溶胶层之下。此前，云和气溶胶激光雷达及红外探路者卫星观测（CALIPSO）532纳米激光雷达观测数据已被用于估算云上汽溶胶（ACA）相对于下层云的相对垂直位置。在此，我们展示了美国国家航空航天局（NASA）云和气溶胶传输系统（CATS）激光雷达的新观测结果。两个季节的CATS 1064纳米观测结果显示，ACA层底部比此前基于CALIPSO 532纳米观测所估计的要低得多。在大约60%的CATS夜间ACA场景中，气溶胶层底部距离下层云顶部在360米范围内。我们的结果对于未来研究东南大西洋地区ACA的微物理间接和半直接效应具有重要意义。
