Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon
Anomalous interactions between the Indian summer monsoon (ISM) circulation and subtropical westerlies are known to trigger breaks in the ISM on subseasonal time-scales, characterised by a pattern of suppressed rainfall over central-north India, and enhanced rainfall over the foothills of the central...
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ftuniveastangl:oai:ueaeprints.uea.ac.uk:89873 2024-04-28T08:12:09+00:00 Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon Umakanth, Uppara Vellore, Ramesh K. Krishnan, R. Choudhury, Ayantika Dey Bisht, Jagat S. H. Di Capua, Giorgia Coumou, Dim Donner, Reik V. 2019-12-01 https://ueaeprints.uea.ac.uk/id/eprint/89873/ https://doi.org/10.1007/s41748-019-00119-8 unknown Umakanth, Uppara, Vellore, Ramesh K., Krishnan, R., Choudhury, Ayantika Dey, Bisht, Jagat S. H., Di Capua, Giorgia, Coumou, Dim and Donner, Reik V. (2019) Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon. Earth Systems and Environment, 3 (3). pp. 353-366. ISSN 2509-9426 doi:10.1007/s41748-019-00119-8 Article PeerReviewed 2019 ftuniveastangl https://doi.org/10.1007/s41748-019-00119-8 2024-04-10T02:17:43Z Anomalous interactions between the Indian summer monsoon (ISM) circulation and subtropical westerlies are known to trigger breaks in the ISM on subseasonal time-scales, characterised by a pattern of suppressed rainfall over central-north India, and enhanced rainfall over the foothills of the central–eastern Himalayas (CEH). An intriguing feature during ISM breaks is the formation of a mid-tropospheric cyclonic circulation anomaly extending over the subtropical and mid-latitude areas of the Asian continent. This study investigates the mechanism of the aforesaid Asian continental mid-tropospheric cyclonic circulation (ACMCC) anomaly using observations and simplified model experiments. The results of our study indicate that the ACMCC during ISM breaks is part of a larger meridional wave train comprising of alternating anticyclonic and cyclonic anomalies that extend poleward from the monsoon region to the Arctic. A lead–lag analysis of mid-tropospheric circulation anomalies suggests that the meridional wave-train generation is linked to latent heating (LH) anomalies over the CEH foothills, Indo-China, and the Indian landmass during ISM breaks. By conducting sensitivity experiments using a simplified global atmospheric general circulation model forced with satellite-derived three-dimensional LH, it is demonstrated that the combined effects of the enhanced LH over the CEH foothills and Indo-China and decreased LH over the Indian landmass during ISM breaks are pivotal for generating the poleward extending meridional wave train and the ACMCC anomaly. At the same time, the spatial extent of the mid-latitude cyclonic anomaly over Far-East Asia is also influenced by the anomalous LH over central–eastern China. While the present findings provide interesting insights into the role of LH anomalies during ISM breaks on the poleward extending meridional wave train, the ACMCC anomaly is found to have important ramifications on the daily rainfall extremes over the Indo-China region. It is revealed from the present analysis that ... Article in Journal/Newspaper Arctic University of East Anglia: UEA Digital Repository Earth Systems and Environment 3 3 353 366 |
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University of East Anglia: UEA Digital Repository |
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ftuniveastangl |
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unknown |
description |
Anomalous interactions between the Indian summer monsoon (ISM) circulation and subtropical westerlies are known to trigger breaks in the ISM on subseasonal time-scales, characterised by a pattern of suppressed rainfall over central-north India, and enhanced rainfall over the foothills of the central–eastern Himalayas (CEH). An intriguing feature during ISM breaks is the formation of a mid-tropospheric cyclonic circulation anomaly extending over the subtropical and mid-latitude areas of the Asian continent. This study investigates the mechanism of the aforesaid Asian continental mid-tropospheric cyclonic circulation (ACMCC) anomaly using observations and simplified model experiments. The results of our study indicate that the ACMCC during ISM breaks is part of a larger meridional wave train comprising of alternating anticyclonic and cyclonic anomalies that extend poleward from the monsoon region to the Arctic. A lead–lag analysis of mid-tropospheric circulation anomalies suggests that the meridional wave-train generation is linked to latent heating (LH) anomalies over the CEH foothills, Indo-China, and the Indian landmass during ISM breaks. By conducting sensitivity experiments using a simplified global atmospheric general circulation model forced with satellite-derived three-dimensional LH, it is demonstrated that the combined effects of the enhanced LH over the CEH foothills and Indo-China and decreased LH over the Indian landmass during ISM breaks are pivotal for generating the poleward extending meridional wave train and the ACMCC anomaly. At the same time, the spatial extent of the mid-latitude cyclonic anomaly over Far-East Asia is also influenced by the anomalous LH over central–eastern China. While the present findings provide interesting insights into the role of LH anomalies during ISM breaks on the poleward extending meridional wave train, the ACMCC anomaly is found to have important ramifications on the daily rainfall extremes over the Indo-China region. It is revealed from the present analysis that ... |
format |
Article in Journal/Newspaper |
author |
Umakanth, Uppara Vellore, Ramesh K. Krishnan, R. Choudhury, Ayantika Dey Bisht, Jagat S. H. Di Capua, Giorgia Coumou, Dim Donner, Reik V. |
spellingShingle |
Umakanth, Uppara Vellore, Ramesh K. Krishnan, R. Choudhury, Ayantika Dey Bisht, Jagat S. H. Di Capua, Giorgia Coumou, Dim Donner, Reik V. Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
author_facet |
Umakanth, Uppara Vellore, Ramesh K. Krishnan, R. Choudhury, Ayantika Dey Bisht, Jagat S. H. Di Capua, Giorgia Coumou, Dim Donner, Reik V. |
author_sort |
Umakanth, Uppara |
title |
Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
title_short |
Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
title_full |
Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
title_fullStr |
Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
title_full_unstemmed |
Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon |
title_sort |
meridionally extending anomalous wave train over asia during breaks in the indian summer monsoon |
publishDate |
2019 |
url |
https://ueaeprints.uea.ac.uk/id/eprint/89873/ https://doi.org/10.1007/s41748-019-00119-8 |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Umakanth, Uppara, Vellore, Ramesh K., Krishnan, R., Choudhury, Ayantika Dey, Bisht, Jagat S. H., Di Capua, Giorgia, Coumou, Dim and Donner, Reik V. (2019) Meridionally extending anomalous wave train over Asia during breaks in the Indian summer monsoon. Earth Systems and Environment, 3 (3). pp. 353-366. ISSN 2509-9426 doi:10.1007/s41748-019-00119-8 |
op_doi |
https://doi.org/10.1007/s41748-019-00119-8 |
container_title |
Earth Systems and Environment |
container_volume |
3 |
container_issue |
3 |
container_start_page |
353 |
op_container_end_page |
366 |
_version_ |
1797579164777185280 |