Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter
Sea surface temperatures (SST) in the North Pacific were extremely warm in the 2021-22 winter associated with the negative phase of the Pacific Decadal Oscillation (PDO). We investigate the large-scale atmospheric responses to the warm SST anomalies through ensemble time-slice experiments of an atmo...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5016188 2023-06-11T04:09:34+02:00 Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter Nishii, K. Taguchi, B. Nakamura, H. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016188 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0277 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016188 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-0277 2023-04-23T23:38:34Z Sea surface temperatures (SST) in the North Pacific were extremely warm in the 2021-22 winter associated with the negative phase of the Pacific Decadal Oscillation (PDO). We investigate the large-scale atmospheric responses to the warm SST anomalies through ensemble time-slice experiments of an atmospheric general circulation model (AGCM) with two different horizontal resolution settings: 100 km and 50 km. In both the 100-km and 50-km experiments, anticyclonic responses in the winter-mean 500-hPa geopotential height fields are found over the North Pacific. The anticyclonic response is stronger in the 50-km AGCM, and its center is located slightly to the west of that obtained in the 100-km AGCM. Blocking frequency over the North Pacific in the 50-km AGCM is significantly increased under the influence of the warm SST anomalies, which may cool the lower stratosphere in the Arctic through suppressing upward planetary-wave propagation from the troposphere. Such increased blocking and cooling in the polar stratosphere are not observed in the response in the 100-km AGCM, suggesting the need for a high-resolution model to obtain a realistic blocking response to midlatitude SST anomalies. Conference Object Arctic GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Arctic Pacific |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Sea surface temperatures (SST) in the North Pacific were extremely warm in the 2021-22 winter associated with the negative phase of the Pacific Decadal Oscillation (PDO). We investigate the large-scale atmospheric responses to the warm SST anomalies through ensemble time-slice experiments of an atmospheric general circulation model (AGCM) with two different horizontal resolution settings: 100 km and 50 km. In both the 100-km and 50-km experiments, anticyclonic responses in the winter-mean 500-hPa geopotential height fields are found over the North Pacific. The anticyclonic response is stronger in the 50-km AGCM, and its center is located slightly to the west of that obtained in the 100-km AGCM. Blocking frequency over the North Pacific in the 50-km AGCM is significantly increased under the influence of the warm SST anomalies, which may cool the lower stratosphere in the Arctic through suppressing upward planetary-wave propagation from the troposphere. Such increased blocking and cooling in the polar stratosphere are not observed in the response in the 100-km AGCM, suggesting the need for a high-resolution model to obtain a realistic blocking response to midlatitude SST anomalies. |
format |
Conference Object |
author |
Nishii, K. Taguchi, B. Nakamura, H. |
spellingShingle |
Nishii, K. Taguchi, B. Nakamura, H. Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
author_facet |
Nishii, K. Taguchi, B. Nakamura, H. |
author_sort |
Nishii, K. |
title |
Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
title_short |
Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
title_full |
Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
title_fullStr |
Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
title_full_unstemmed |
Large-scale atmospheric response to warm SST anomalies in the North Pacific in the 2021-22 winter |
title_sort |
large-scale atmospheric response to warm sst anomalies in the north pacific in the 2021-22 winter |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016188 |
geographic |
Arctic Pacific |
geographic_facet |
Arctic Pacific |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0277 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016188 |
op_doi |
https://doi.org/10.57757/IUGG23-0277 |
_version_ |
1768383506910543872 |