Mechanism Study of Tropical Cyclone Impact on East Asian Subtropical Upper-Level Jet: a Numerical Case Investigation

作者：Chen, Xian; Zhong, Zhong^*; Lu, Wei

来源：Asia-Pacific Journal of Atmospheric Sciences, 2018, 54(4): 575-585.

DOI：10.1007/s13143-018-0087-y

• Tropical cyclone
• Soudelor
• East Asian subtropical upper-level jet
• Latent heat
• Mechanism

In the case study of this paper, sensitivity experiments are carried out using the mesoscale non-hydrostatic Weather Research and Forecasting (WRF) model to investigate the impact of tropical cyclone (TC) Soudelor (2003) on the East Asian subtropical upper-level jet (EASJ) before TC Soudelor transformed into an extratropical cyclone. The physical mechanism for changes in the EASJ intensity and position caused by TC Soudelor is explored. Results indicate that TC Soudelor would warm the air in the middle and upper troposphere over the Japan Sea and the adjacent areas through stimulating northward propagating teleconnection pattern as well as releasing large amounts of latent heat, which led to increase (decrease) the meridional air temperature gradient to the south (north) below the EASJ axis. As a result, the geopotential height abnormally increased in the upper troposphere, resulting in an anomalous anticyclonic circulation belt along the EASJ axis. Correspondingly, the westerly winds to the north (south) of the EASJ axis intensified (weakened) and the EASJ axis shifted northward by one degree. The case study also suggests that before the extratropical cyclone transition of TC Soudelor, the TC activities had exerted significant impacts on the EASJ through thermodynamic processes.

• 出版日期2018-11
• 单位中国人民解放军国防科学技术大学; 南京大学