Boundary layer sources for the Asian anticyclone: Regional contributions to a vertical conduit
Boundary layer sources for the Asian anticyclone: Regional contributions to a vertical conduit
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DOI：
10.1002/jgrd.50142
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发表时间：
2013-03-27
影响因子：
4.4
通讯作者：
Pan, Laura L.
中科院分区：
文献类型：
--
作者：
Bergman, John W.;Fierli, Federico;Pan, Laura L.
利用2011年8月100毫巴和200毫巴反气旋内启动的反向轨迹，研究了空气从行星边界层进入亚洲夏季风反气旋的输送。输送通过一条以青藏高原南部为中心的明确管道进行，对流在那里将气团送入反气旋。作为一种动力特征，该管道有别于反气旋。因此，尽管反气旋影响通过对流层上层和平流层下层的输送，但它本身并不定义通过该区域的输送管道。为了量化模型的敏感性，使用来自多个分析数据集(欧洲中期天气预报中心、国家环境预测中心的全球预报系统和NASA的现代研究和应用回顾分析[MERRA])的风场以及探索垂直运动和水平分辨率的作用的综合修改数据集来计算包裹轨迹。所有计算结果都表明，青藏高原和印度/东南亚等大尺度地区的反气旋对PBL来源的相对贡献最大。然而，他们对最近在PBL中的反气旋内空气的总比例存在分歧。在200mbar，由于这些数据中有问题的垂直运动，使用MERRA的计算是明显的异常值。100mbar的不同数据集之间的巨大差异与水平分辨率更密切相关。据推测，这反映了深层、小规模对流上升气流对输送到100毫巴的重要性。引文：Bergman，J.W.，F.Fierli，E.J.Jensen，S.Honomichl和L.L.潘(2013)，亚洲反气旋的边界层源：区域对垂直管道的贡献，J.地球物理。地址：10.1002/jgrd.50142。
The transport of air from the planetary boundary layer (PBL) into the Asian Summer Monsoon anticyclone is investigated using backward trajectories initiated within the anti-cyclone at 100 mb and 200 mb during August 2011. Transport occurs through a well-defined conduit centered over the southern Tibetan plateau, where convection lofts air parcels into the anticyclone. The conduit, as a dynamical feature, is distinct from the anticyclone. Thus, while the anticyclone influences transport through the upper troposphere and lower stratosphere, it does not by itself define a transport pipeline through that region. To quantify model sensitivities, parcel trajectories are calculated using wind fields from multiple analysis data sets (European Centre for Medium-Range Weather Forecasts, National Center for Environmental Prediction's Global Forecasting System, and NASA's Modern-Era Retrospective Analysis for Research and Applications [MERRA]) and from synthetically modified data sets that explore the roles of vertical motion and horizontal resolution for discrepancies among these calculations. All calculations agree on the relative contributions to PBL sources for the anticyclone from large-scale regions with Tibetan Plateau and India/SE Asia being the most important. However, they disagree on the total fraction of air within the anticyclone that was recently in the PBL. At 200 mbar, calculations using MERRA are clear outliers due to problematic vertical motion in those data. Large differences among the different data sets at 100 mbar are more closely related to horizontal resolution. It is speculated that this reflects the importance of deep, small-scale convective updrafts for transport to 100 mbar. Citation: Bergman, J. W., F. Fierli, E. J. Jensen, S. Honomichl, and L. L. Pan (2013), Boundary layer sources for the Asian anticyclone: Regional contributions to a vertical conduit, J. Geophys. Res. Atmos., 118, 2560-2575, doi:10.1002/jgrd.50142.