Study on the Structure of a Horizontal Shear Line over the Tibetan Plateau Based on CRA-Interim Datasets and Its Comparison with ERA-Interim Datasets

作     者：YAO Xiu-ping ZHANG Shuo BAO Xiao-hong SHI Chun-xiang LIU Jing-wei 姚秀萍;张硕;包晓红;师春香;刘景卫

作者机构：China Meteorological Administration Training CentreBeijing 100081 China Beijing Institute of Applied MeteorologyBeijing 100029 China Chinese Academy of Meteorological SciencesBeijing 100081 China National Meteorological CentreBeijing 100081 China 

出 版 物：《Journal of Tropical Meteorology》 (热带气象学报（英文版）)

年 卷 期：2020年第26卷第4期

页      面：483-494页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：National Science Foundation of China (42030611,91937301) The Second Tibetan Plateau Scientific Expedition and Research (STEP) Program (2019QZKK0105) 

主　　题：CRA-Interim datasets ERA-Interim datasets horizontal shear line over the Tibetan Plateau structure 

摘      要：The CRA-Interim trial production of the global atmospheric reanalysis for 10 years from 2007 to 2016 was carried out by the China Meteorological Administration in 2017. The structural characteristics of the horizontal shear line over the Tibetan Plateau (TPHSL) based on the CRA-Interim datasets are examined by objectively identifying the shear line, and are compared with the analysis results of the European Centre for Medium-Range Weather Forecasts reanalysis data (ERA-Interim). The case occurred at 18UTC on July 5, 2016. The results show that both of the ERA-Interim and CRA-Interim datasets can well reveal the circulation background and the dynamic and thermal structure characteristics of TPHSL, and they have shown some similar features. The middle and high latitudes at 500 hPa are characterized by the circulation situation oftwo troughs and two ridges, and at 200 hPa, the TPHSL is located in the northeast quadrant of the South Asian High Pressure (SAHP). The TPHSL locates in the positive vorticity zone and passes through the positive vorticity center corresponding to the ascending motion. Near the TPHSL, the contours of pseudo-equivalent potential temperature (θse) tend to be intensive, with a high-value center on the south side of the TPHSL. The TPHSL can extend to460 hPa and vertically inclines northward. There is a positive vorticity zone near the TPHSL which is also characterized by the northward inclination with the height, the ascending motion near the TPHSL can extend to 300 hPa, and the atmospheric layer above the TPHSL is stable. However, the intensities of the TPHSL’s structure characteristics analyzed with the two datasets are different, revealing the relatively strong intensity of geopotential height field, vertical velocity field, vorticity field and divergence field from the CRA-Interim datasets. In addition, the vertical profiles of the dynamic and water vapor thermal physical quantities of the two datasets are also consistent in the east and west