Spatiotemporal variation of aerosol and potential long-range transport impact over Tibetan Plateau, China
Spatiotemporal variation of aerosol and potential long-range transport impact over Tibetan Plateau, China
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DOI：
10.5194/acp-2019-444
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Jun Zhu;X. Xia;H. Che;Jun Wang;Z. Cong;T. Zhao;Shi-chang Kang;Xuelei Zhang;Xingna Yu;
中科院分区：
文献类型：
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作者：
Jun Zhu;X. Xia;H. Che;Jun Wang;Z. Cong;T. Zhao;Shi-chang Kang;Xuelei Zhang;Xingna Yu;
抽象。利用青藏高原5个观测站多年的太阳光度计（CE 318）观测资料、中分辨率成像光谱仪（MODIS）和正交偏振云-气溶胶激光雷达（CALIOP）卫星气溶胶产品资料，分析了青藏高原气溶胶光学特性的长期时空变化特征及其从周边地区向青藏高原的潜在远距离输送，来自混合单粒子拉格朗日积分轨迹（HYSPLIT）的后向轨迹分析和戈达德地球观测系统（GEOS）-化学传输模型的模型模拟。地面观测结果表明，青藏高原大部分站点的气溶胶光学厚度（AOD）在过去几十年中呈增加趋势，拉萨站为0.001 ± 0.003/年，Mt_WLG站为0.013 ± 0.003/年，NAM_CO站为0.002 ± 0.002/年，QOMS_CAS站为0.000 ± 0.002/年。除Mt_WLG站呈明显下降趋势外，大部分站点的气溶胶消光指数（EAE）也呈上升趋势。在空间上，MODIS观测的气溶胶光学厚度在靠近塔克拉玛干沙漠的西北边缘和柴达木盆地东部呈负趋势，而在TP的其他大部分地区呈略正的趋势。不同气溶胶类型和来源对TP 5个站点的污染日（CE 318 AOD 440 nm > 0.4）有贡献：拉萨、Mt_WLG和Muztagh以沙尘为主，来源于塔克拉玛干沙漠，而NAM_CO和QOMS_CAS以细气溶胶污染为主，来源于南亚。2016年4月28日至5月3日拉萨、纳木错和青藏高原的气溶胶污染个例分析表明，南亚地区的烟雾气溶胶被抬升至10 km，并输送至TP，而塔克拉玛干沙漠的沙尘则可以沿TP北坡向上输送至TP中心。因此，远距离输送严重影响TP上空的气溶胶负荷。
Abstract. The long-term temporal-spatial variations of aerosol optical properties in Tibetan Plateau (TP) and the potential long-range transport from surrounding areas to TP were analyzed in this work, by using multiple years of sunphotometer measurements (CE318) at five stations in TP, satellite aerosol productions from Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), back-trajectory analysis from the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) and model simulation of the Goddard Earth Observing System (GEOS)-Chem chemistry transport model. The results from ground-based observations show that the annual aerosol optical depth (AOD) at most TP sites increased in the past decades with trends of 0.001 ± 0.003/year at Lhasa, 0.013 ± 0.003/year at Mt_WLG, 0.002 ± 0.002/year at NAM_CO, and 0.000 ± 0.002/year at QOMS_CAS. The increasing trend is also found for the aerosol Extinction Ångstrom exponent (EAE) at most sites, except for Mt_WLG sites with an obvious decreasing trend. Spatially, the AOD observed from MODIS shows negative trends in the northwest edge closed to the Taklimakan Desert and east of the Qaidam Basin and slightly positive trends in most of the other area of TP. Different aerosol types and sources contribute to the polluted day (with CE318 AOD at 440 nm > 0.4) in the five sites of TP: dust dominant in Lhasa, Mt_WLG and Muztagh with sources from the Taklimakan Desert but fine aerosol pollution dominant at NAM_CO and QOMS_CAS with the transport from South Asia. A case of aerosol pollution at Lhasa, NAM_CO and QOMS_CAS during 28 April–3 May 2016 reveals that the smoke aerosols in South Asia were lifted up to 10 km and transported to TP, while the dust from Taklimakan Desert could climb the north slope of TP and then be transported to center TP. The long-range transport thereby seriously impact aerosol loading over the TP.