Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño
The El Niño-related anomalous western North Pacific anticyclone (WNPAC) shows different latitudinal extensions during the El Niño decaying summer, which determines the moisture transport to different regions and leads to distinct climate impacts over East Asia. It is known that both the north Indian...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5018620 2023-07-02T03:33:08+02:00 Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño Feng, J. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018620 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2208 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018620 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-2208 2023-06-11T23:39:57Z The El Niño-related anomalous western North Pacific anticyclone (WNPAC) shows different latitudinal extensions during the El Niño decaying summer, which determines the moisture transport to different regions and leads to distinct climate impacts over East Asia. It is known that both the north Indian Ocean (NIO) sea surface temperature (SST) and the tropical North Atlantic (TNA) SST can generate a WNPAC in summer. However, the difference between the NIO SST-forced WNPAC and the TNA SST-forced WNPAC has hardly been noted before now. This study shows that the NIO SST warming makes the WNPAC contract southward, whereas the TNA SST warming makes the WNPAC extend northward. The NIO SST warming generates the WNPAC via a Kelvin wave response. Owing to the limited domain of Kelvin wave activity, the Kelvin wave-induced suppressed convection over the western Pacific is confined south of 20°N, resulting in the WNPAC being concentrated in the low latitudes. In contrast, the TNA SST warming generates the WNPAC via a Rossby wave-induced divergence/convergence chain response over the Pacific. The Rossby wave-induced suppressed convection over the central-eastern Pacific north of the Equator leads to enhanced convection on its southwest side, which further generates the low-level anomalous divergent winds over the western North Pacific and suppresses convection there. In this process, the suppressed convection over the western North Pacific is pushed more northward, thus producing a WNPAC extending northward. Conference Object North Atlantic GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Pacific Indian |
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Open Polar |
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GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
The El Niño-related anomalous western North Pacific anticyclone (WNPAC) shows different latitudinal extensions during the El Niño decaying summer, which determines the moisture transport to different regions and leads to distinct climate impacts over East Asia. It is known that both the north Indian Ocean (NIO) sea surface temperature (SST) and the tropical North Atlantic (TNA) SST can generate a WNPAC in summer. However, the difference between the NIO SST-forced WNPAC and the TNA SST-forced WNPAC has hardly been noted before now. This study shows that the NIO SST warming makes the WNPAC contract southward, whereas the TNA SST warming makes the WNPAC extend northward. The NIO SST warming generates the WNPAC via a Kelvin wave response. Owing to the limited domain of Kelvin wave activity, the Kelvin wave-induced suppressed convection over the western Pacific is confined south of 20°N, resulting in the WNPAC being concentrated in the low latitudes. In contrast, the TNA SST warming generates the WNPAC via a Rossby wave-induced divergence/convergence chain response over the Pacific. The Rossby wave-induced suppressed convection over the central-eastern Pacific north of the Equator leads to enhanced convection on its southwest side, which further generates the low-level anomalous divergent winds over the western North Pacific and suppresses convection there. In this process, the suppressed convection over the western North Pacific is pushed more northward, thus producing a WNPAC extending northward. |
format |
Conference Object |
author |
Feng, J. |
spellingShingle |
Feng, J. Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
author_facet |
Feng, J. |
author_sort |
Feng, J. |
title |
Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
title_short |
Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
title_full |
Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
title_fullStr |
Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
title_full_unstemmed |
Roles of north Indian Ocean and tropical Atlantic SST in latitudinal extension of western North Pacific anticyclone during El Niño |
title_sort |
roles of north indian ocean and tropical atlantic sst in latitudinal extension of western north pacific anticyclone during el niño |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018620 |
geographic |
Pacific Indian |
geographic_facet |
Pacific Indian |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-2208 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018620 |
op_doi |
https://doi.org/10.57757/IUGG23-2208 |
_version_ |
1770272949688860672 |