{"title":"南环流模式对孟加拉湾热带气旋频率影响的年代际变化","authors":"Dickson Mbigi, Ziniu Xiao","doi":"10.1002/joc.8598","DOIUrl":null,"url":null,"abstract":"<p>The current study investigates the modulation of the tropical cyclone (TC) frequency (TCF) over the Bay of Bengal (BoB) by the southern annular mode (SAM). The analysis reveals that the SAM–TCF relationship during October–November–December has undergone interdecadal changes from significant during 1971–1994 to insignificant during 1995–2021. This contrasting influence of the SAM on the TCF occurrence is also echoed in the large-scale environmental variables conducive to forming tropical cyclones (TCs). Based on the possible mechanism, we found that the SAM can imprint tripole sea surface temperature (SST) patterns in the southern Indian Ocean via altering surface wind speed from 1971 to 1994. The SAM-related tripole SST pattern induces the surface-level anticyclone anomaly, which enhances the south easterlies towards the western equatorial Indian Ocean. Such intensified anomalous wind crosses the equator and diverts towards the east to form the cyclone anomaly in the BoB. Meanwhile, at 200 hPa, the anomalous anticyclone over western Australia induces divergent wind flows over the study region. Consequently, the ascending motion in BoB promotes the tropical cyclone generation. During 1995–2021, however, the SAM is associated with the dipole SST pattern in the southern Indian Ocean. Correspondingly, the SAM-related dipole SST yields anomalous atmospheric circulations confined to the Southern Hemisphere and eventually fails to impact the formation of TCs in the northern Indian Ocean, where the study region is located. The findings of this research can be useful in advancing our knowledge of the interannual variability of TCs activity in the BoB based on the remote climate signal.</p>","PeriodicalId":13779,"journal":{"name":"International Journal of Climatology","volume":"44 13","pages":"4592-4610"},"PeriodicalIF":3.5000,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Interdecadal change in the influence of the southern annular mode to the tropical cyclone frequency over the Bay of Bengal\",\"authors\":\"Dickson Mbigi, Ziniu Xiao\",\"doi\":\"10.1002/joc.8598\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>The current study investigates the modulation of the tropical cyclone (TC) frequency (TCF) over the Bay of Bengal (BoB) by the southern annular mode (SAM). The analysis reveals that the SAM–TCF relationship during October–November–December has undergone interdecadal changes from significant during 1971–1994 to insignificant during 1995–2021. This contrasting influence of the SAM on the TCF occurrence is also echoed in the large-scale environmental variables conducive to forming tropical cyclones (TCs). Based on the possible mechanism, we found that the SAM can imprint tripole sea surface temperature (SST) patterns in the southern Indian Ocean via altering surface wind speed from 1971 to 1994. The SAM-related tripole SST pattern induces the surface-level anticyclone anomaly, which enhances the south easterlies towards the western equatorial Indian Ocean. Such intensified anomalous wind crosses the equator and diverts towards the east to form the cyclone anomaly in the BoB. Meanwhile, at 200 hPa, the anomalous anticyclone over western Australia induces divergent wind flows over the study region. Consequently, the ascending motion in BoB promotes the tropical cyclone generation. During 1995–2021, however, the SAM is associated with the dipole SST pattern in the southern Indian Ocean. Correspondingly, the SAM-related dipole SST yields anomalous atmospheric circulations confined to the Southern Hemisphere and eventually fails to impact the formation of TCs in the northern Indian Ocean, where the study region is located. The findings of this research can be useful in advancing our knowledge of the interannual variability of TCs activity in the BoB based on the remote climate signal.</p>\",\"PeriodicalId\":13779,\"journal\":{\"name\":\"International Journal of Climatology\",\"volume\":\"44 13\",\"pages\":\"4592-4610\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-08-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Climatology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/joc.8598\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Climatology","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/joc.8598","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
Interdecadal change in the influence of the southern annular mode to the tropical cyclone frequency over the Bay of Bengal
The current study investigates the modulation of the tropical cyclone (TC) frequency (TCF) over the Bay of Bengal (BoB) by the southern annular mode (SAM). The analysis reveals that the SAM–TCF relationship during October–November–December has undergone interdecadal changes from significant during 1971–1994 to insignificant during 1995–2021. This contrasting influence of the SAM on the TCF occurrence is also echoed in the large-scale environmental variables conducive to forming tropical cyclones (TCs). Based on the possible mechanism, we found that the SAM can imprint tripole sea surface temperature (SST) patterns in the southern Indian Ocean via altering surface wind speed from 1971 to 1994. The SAM-related tripole SST pattern induces the surface-level anticyclone anomaly, which enhances the south easterlies towards the western equatorial Indian Ocean. Such intensified anomalous wind crosses the equator and diverts towards the east to form the cyclone anomaly in the BoB. Meanwhile, at 200 hPa, the anomalous anticyclone over western Australia induces divergent wind flows over the study region. Consequently, the ascending motion in BoB promotes the tropical cyclone generation. During 1995–2021, however, the SAM is associated with the dipole SST pattern in the southern Indian Ocean. Correspondingly, the SAM-related dipole SST yields anomalous atmospheric circulations confined to the Southern Hemisphere and eventually fails to impact the formation of TCs in the northern Indian Ocean, where the study region is located. The findings of this research can be useful in advancing our knowledge of the interannual variability of TCs activity in the BoB based on the remote climate signal.
期刊介绍:
The International Journal of Climatology aims to span the well established but rapidly growing field of climatology, through the publication of research papers, short communications, major reviews of progress and reviews of new books and reports in the area of climate science. The Journal’s main role is to stimulate and report research in climatology, from the expansive fields of the atmospheric, biophysical, engineering and social sciences. Coverage includes: Climate system science; Local to global scale climate observations and modelling; Seasonal to interannual climate prediction; Climatic variability and climate change; Synoptic, dynamic and urban climatology, hydroclimatology, human bioclimatology, ecoclimatology, dendroclimatology, palaeoclimatology, marine climatology and atmosphere-ocean interactions; Application of climatological knowledge to environmental assessment and management and economic production; Climate and society interactions