Asian dust outflow in the PBL and free atmosphere retrieved by NASA CALIPSO and an assimilated dust transport model
Asian dust outflow in the PBL and free atmosphere retrieved by NASA CALIPSO and an assimilated dust transport model
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DOI：
10.5194/acp-9-1227-2009
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发表时间：
2008-05
影响因子：
6.3
通讯作者：
Y. Hara;K. Yumimoto;I. Uno;A. Shimizu;N. Sugimoto;Zhaoyan Liu;D. Winker
中科院分区：
文献类型：
--
作者：
Y. Hara;K. Yumimoto;I. Uno;A. Shimizu;N. Sugimoto;Zhaoyan Liu;D. Winker
抽象的。利用星载反向散射激光雷达、正交偏振云气溶胶激光雷达（CALIOP）的结果以及基于地面 NIES 激光雷达网络的数据同化版本的尘埃传输模型（RC4）获得的结果，阐明了 2007 年 5 月下旬相继发生的行星边界层（PBL）和自由大气中的亚洲尘埃传输的三维结构。 RC4模拟的沙尘层深度和垂直、水平结构与CALIOP从沙源区到远下游区域的观测结果一致。阐明了亚洲沙尘在PBL和自由大气中的两个重要传输机制：在发达的低压系统的干槽区域内发生低水平沙尘暴发，以及在低压系统的温暖区域内形成升高的沙尘层。我们还使用 532 nm 处的粒子去偏振比 (PDR) 以及 1064 nm 和 532 nm 处的色彩比 (CR) 来表示纯尘埃粒子的老化。在尘源区域均匀观察到具有高 PDR 的气溶胶。沙尘云输送至东部顺风区时，1 km以下层内出现低PDR、高CR的气溶胶，表明表层存在球形气溶胶与尘埃的混合状态。
Abstract. Three-dimensional structures of Asian dust transport in the planetary boundary layer (PBL) and free atmosphere occurring successively during the end of May 2007 were clarified using results of space-borne backscatter lidar, Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), and results obtained using a data-assimilated version of a dust transport model (RC4) based on a ground-based NIES lidar network. The dust layer depths and the vertical and horizontal structure simulated by RC4 agreed with those of CALIOP observations from the dust source region to the far-downstream region. Two important transport mechanisms of Asian dust in the PBL and free atmosphere were clarified: a low-level dust outbreak within the dry slot region of a well-developed low-pressure system, and formation of an elevated dust layer within the warm sector of a low-pressure system. We also represent the aging of pure dust particles using the particle depolarization ratio (PDR) at 532 nm and the color ratio (CR) at 1064 nm and 532 nm. Aerosols with high PDR were observed uniformly over the dust source region. While the dust cloud was transported to the eastern downwind regions, aerosols with low PDR and high CR occur in the layer of less than 1 km height, suggesting a mixing state of spherical aerosols and dust in the surface layer.