Westward shift of tropical cyclogenesis over the southern Indian Ocean
Tropical cyclones (TCs), commonly called cyclones in the southern Indian Ocean (SIO), represent one of the most devastating disasters in the oceanfront regions of Africa. The present study explores the long-term tendency of annual mean TC genesis location in the SIO. A notable westward shift is dete...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2024-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ad1d9b |
| _version_ | 1797305120600358912 |
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| author | Xi Cao Masahiro Watanabe Renguang Wu Liang Wu Difei Deng Yao Ha Mengchen Xu Meng Yuan Yifeng Dai Zhencai Du |
| author_facet | Xi Cao Masahiro Watanabe Renguang Wu Liang Wu Difei Deng Yao Ha Mengchen Xu Meng Yuan Yifeng Dai Zhencai Du |
| author_sort | Xi Cao |
| collection | DOAJ |
| description | Tropical cyclones (TCs), commonly called cyclones in the southern Indian Ocean (SIO), represent one of the most devastating disasters in the oceanfront regions of Africa. The present study explores the long-term tendency of annual mean TC genesis location in the SIO. A notable westward shift is detected in the SIO TC genesis longitude since 1979, which is linked to an increase in the TC genesis frequency in the southwestern SIO and a decrease in the TC genesis frequency in the northeastern SIO. The dipole trend pattern of the TC genesis frequency in the SIO is intimately linked to the weakening of the westerly vertical wind shear over the western SIO and the strengthening of the easterly vertical wind shear over the eastern SIO, resulting from a reduced meridional temperature gradient. The weakened meridional temperature gradient is attributed to the enhanced warming of the subtropical troposphere that is a response of atmospheric temperature to global warming. Our study implies a potential increase in the risks faced by coastal and island countries in eastern Africa. |
| first_indexed | 2024-03-08T00:21:17Z |
| format | Article |
| id | doaj.art-c377ea18f6d643d59e7018d6f629f141 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-08T00:21:17Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-c377ea18f6d643d59e7018d6f629f1412024-02-16T09:51:53ZengIOP PublishingEnvironmental Research Letters1748-93262024-01-0119303401610.1088/1748-9326/ad1d9bWestward shift of tropical cyclogenesis over the southern Indian OceanXi Cao0https://orcid.org/0000-0002-2064-7018Masahiro Watanabe1Renguang Wu2https://orcid.org/0000-0003-4712-2251Liang Wu3https://orcid.org/0000-0001-9410-0050Difei Deng4https://orcid.org/0000-0001-5490-6797Yao Ha5Mengchen Xu6Meng Yuan7Yifeng Dai8Zhencai Du9Center for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing, People’s Republic of China; Atmosphere and Ocean Research Institute, University of Tokyo , Chiba, JapanAtmosphere and Ocean Research Institute, University of Tokyo , Chiba, JapanSchool of Earth Sciences, Zhejiang University , Hangzhou, Zhejiang, People’s Republic of ChinaCenter for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing, People’s Republic of ChinaUniversity of New South Wales , Canberra, AustraliaCollege of Meteorology and Oceanography, National University of Defense Technology , Changsha, People’s Republic of ChinaCenter for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing, People’s Republic of ChinaCenter for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing, People’s Republic of ChinaTongji Zhejiang College , Jiaxing, Zhejiang, People’s Republic of ChinaCenter for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences , Beijing, People’s Republic of ChinaTropical cyclones (TCs), commonly called cyclones in the southern Indian Ocean (SIO), represent one of the most devastating disasters in the oceanfront regions of Africa. The present study explores the long-term tendency of annual mean TC genesis location in the SIO. A notable westward shift is detected in the SIO TC genesis longitude since 1979, which is linked to an increase in the TC genesis frequency in the southwestern SIO and a decrease in the TC genesis frequency in the northeastern SIO. The dipole trend pattern of the TC genesis frequency in the SIO is intimately linked to the weakening of the westerly vertical wind shear over the western SIO and the strengthening of the easterly vertical wind shear over the eastern SIO, resulting from a reduced meridional temperature gradient. The weakened meridional temperature gradient is attributed to the enhanced warming of the subtropical troposphere that is a response of atmospheric temperature to global warming. Our study implies a potential increase in the risks faced by coastal and island countries in eastern Africa.https://doi.org/10.1088/1748-9326/ad1d9btropical cyclogenesissouthern Indian Oceanwestward shiftvertical wind shearmeridional temperature gradient |
| spellingShingle | Xi Cao Masahiro Watanabe Renguang Wu Liang Wu Difei Deng Yao Ha Mengchen Xu Meng Yuan Yifeng Dai Zhencai Du Westward shift of tropical cyclogenesis over the southern Indian Ocean Environmental Research Letters tropical cyclogenesis southern Indian Ocean westward shift vertical wind shear meridional temperature gradient |
| title | Westward shift of tropical cyclogenesis over the southern Indian Ocean |
| title_full | Westward shift of tropical cyclogenesis over the southern Indian Ocean |
| title_fullStr | Westward shift of tropical cyclogenesis over the southern Indian Ocean |
| title_full_unstemmed | Westward shift of tropical cyclogenesis over the southern Indian Ocean |
| title_short | Westward shift of tropical cyclogenesis over the southern Indian Ocean |
| title_sort | westward shift of tropical cyclogenesis over the southern indian ocean |
| topic | tropical cyclogenesis southern Indian Ocean westward shift vertical wind shear meridional temperature gradient |
| url | https://doi.org/10.1088/1748-9326/ad1d9b |
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