期刊
INTERNATIONAL JOURNAL OF CLIMATOLOGY
卷 41, 期 1, 页码 439-455出版社
WILEY
DOI: 10.1002/joc.6629
关键词
diabatic heating; potential vorticity (PV); surface PV; surface PV budget; Tibetan Plateau
资金
- Key Research Program of Frontier Sciences of Chinese Academy of Sciences [QYZDY-SSW-DQC018]
- National Natural Science Foundation of China [41730963, 91637312, 91737306, 91837101]
- National Oceanic and Atmospheric Administration (NOAA)
- GES DISC
- Global Modeling and Assimilation Office (GMAO)
The study reveals the significant vertical and horizontal components of surface potential vorticity on the Tibetan Plateau, with the vertical component dominating and the horizontal component playing a key role, especially on the slopes. The surface potential vorticity budget equation is well balanced in terms of climate mean and synoptic processes, with a prominent diurnal cycle in June. Positive potential vorticity generation due to diabatic heating is crucial for the formation, development, and movement of the Tibetan Plateau vortex.
The variability of interior atmospheric potential vorticity (PV) is linked with PV generation at the Earth's surface. The present paper reveals the features of the surface PV and provides a stepping stone to investigate the surface PV budget. In this study, the formats of the PV and PV budget adopting a generalized vertical coordinate were theoretically examined to facilitate the calculation of the surface PV and its budget. Results show that the formats of the PV and PV budget equations are independent of the vertical coordinate. While the vertical component of the surface PV dominates over the platform of the Tibetan Plateau, the horizontal component plays an important role over the slopes of the Tibetan Plateau, especially the southern slope owing to the strong in-situ meridional gradient of the potential temperature. These results indicate that the employment of complete surface PV not only provides a finer PV structure but also more appropriately reveals its effect on atmospheric circulation. Diagnosis based on reanalysis and model output demonstrates that the surface PV budget equation is well balanced both in terms of the climate mean and synoptic process, and the surface PV budget in June has a prominent diurnal cycle. The diabatic heating with a minimum in the early morning and a maximum from evening to midnight contributes dominantly to this diurnal cycle. It is further indicated that positive PV generation due to diabatic heating is essential for the formation, development, and movement of the Tibetan Plateau vortex.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据