Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study
Under the wintertime background of westerly flows, heavy rainfall often occurs first over southwestern China and then spreads eastward downstream to southeastern China, causing serious impact on a large scope of southern China. By using the synoptic diagnosis and dynamic analysis methods, we examine...
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| Format: | Article |
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Frontiers Media S.A.
2023-02-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2023.1107674/full |
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| author | Juyue Yin Juyue Yin Junpeng Yuan Juan Peng Xiaohang Cao Wei Duan Yating Nan Mengni Mao Tao Feng |
| author_facet | Juyue Yin Juyue Yin Junpeng Yuan Juan Peng Xiaohang Cao Wei Duan Yating Nan Mengni Mao Tao Feng |
| author_sort | Juyue Yin |
| collection | DOAJ |
| description | Under the wintertime background of westerly flows, heavy rainfall often occurs first over southwestern China and then spreads eastward downstream to southeastern China, causing serious impact on a large scope of southern China. By using the synoptic diagnosis and dynamic analysis methods, we examined a typical eastward-moving heavy rainfall event that occurred over southwestern China on January 8–9, 2015 and then gradually spread eastward to southeastern China on January 10–13. The results show the important role of the Rossby wave train propagating along the subtropical westerly jet in “pushing” the eastward movement of heavy rainfall over southern China. The remote Rossby wave train influenced the variation of heavy rainfall by modifying the local circulation. The Rossby wave train can change the morphology of the East Asian subtropical jet via wave—jet interactions and modify the related secondary upward circulation in the entrance area of the jet, providing favorable dynamic conditions for the occurrence of heavy rainfall. The Rossby wave train can also influence the low-level south branch trough by modifying the associated baroclinic energy conversion process under a background of deep layer subsidence, which favors the transport of plentiful water vapor to the region of heavy rainfall over southern China. The eastward-propagating Rossby wave train pushed the upper level East Asian subtropical jet and the lower level south branch trough as a whole while simultaneously moving east, which caused the region of heavy rainfall to move from southwestern to southeastern China. These results will help to provide a scientific basis for forecasting winter rainfall over southern China. |
| first_indexed | 2024-04-10T16:42:42Z |
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| id | doaj.art-e80ed08b4bb246d38ad14ace0da16c1e |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-10T16:42:42Z |
| publishDate | 2023-02-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Earth Science |
| spelling | doaj.art-e80ed08b4bb246d38ad14ace0da16c1e2023-02-08T05:59:16ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-02-011110.3389/feart.2023.11076741107674Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case studyJuyue Yin0Juyue Yin1Junpeng Yuan2Juan Peng3Xiaohang Cao4Wei Duan5Yating Nan6Mengni Mao7Tao Feng8Key Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaYuxi Meteorological Bureau, Yuxi, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaYunnan Institute of Meteorology Sciences, Kunming, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaKey Laboratory of Atmospheric Environment and Processes in the Boundary Layer Over the Low-Latitude Plateau Region, Department of Atmospheric Sciences, Yunnan University, Kunming, ChinaUnder the wintertime background of westerly flows, heavy rainfall often occurs first over southwestern China and then spreads eastward downstream to southeastern China, causing serious impact on a large scope of southern China. By using the synoptic diagnosis and dynamic analysis methods, we examined a typical eastward-moving heavy rainfall event that occurred over southwestern China on January 8–9, 2015 and then gradually spread eastward to southeastern China on January 10–13. The results show the important role of the Rossby wave train propagating along the subtropical westerly jet in “pushing” the eastward movement of heavy rainfall over southern China. The remote Rossby wave train influenced the variation of heavy rainfall by modifying the local circulation. The Rossby wave train can change the morphology of the East Asian subtropical jet via wave—jet interactions and modify the related secondary upward circulation in the entrance area of the jet, providing favorable dynamic conditions for the occurrence of heavy rainfall. The Rossby wave train can also influence the low-level south branch trough by modifying the associated baroclinic energy conversion process under a background of deep layer subsidence, which favors the transport of plentiful water vapor to the region of heavy rainfall over southern China. The eastward-propagating Rossby wave train pushed the upper level East Asian subtropical jet and the lower level south branch trough as a whole while simultaneously moving east, which caused the region of heavy rainfall to move from southwestern to southeastern China. These results will help to provide a scientific basis for forecasting winter rainfall over southern China.https://www.frontiersin.org/articles/10.3389/feart.2023.1107674/fulleastward moving heavy rainfall eventsouthern ChinaRossby wave trainsouth branch troughEast Asian subtropical jet |
| spellingShingle | Juyue Yin Juyue Yin Junpeng Yuan Juan Peng Xiaohang Cao Wei Duan Yating Nan Mengni Mao Tao Feng Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study Frontiers in Earth Science eastward moving heavy rainfall event southern China Rossby wave train south branch trough East Asian subtropical jet |
| title | Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study |
| title_full | Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study |
| title_fullStr | Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study |
| title_full_unstemmed | Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study |
| title_short | Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study |
| title_sort | role of the subtropical westerly jet wave train in the eastward moving heavy rainfall event over southern china in winter a case study |
| topic | eastward moving heavy rainfall event southern China Rossby wave train south branch trough East Asian subtropical jet |
| url | https://www.frontiersin.org/articles/10.3389/feart.2023.1107674/full |
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