Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections
The value added from dynamic downscaling in climate projections of extratropical cyclones over the southwestern South Atlantic Ocean (SAO) is evaluated. For this purpose, the Regional Climate Model version 4 (RegCM4) is nested in the Hadley Global Environment Model 2 ‐ Earth System (HadGEM2‐ES) glob...
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crwiley:10.1002/joc.5468 2024-10-13T14:10:47+00:00 Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections Reboita, Michelle S. da Rocha, Rosmeri P. de Souza, Marcelo R. Llopart, Marta Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico 2018 http://dx.doi.org/10.1002/joc.5468 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.5468 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.5468 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor International Journal of Climatology volume 38, issue 6, page 2866-2879 ISSN 0899-8418 1097-0088 journal-article 2018 crwiley https://doi.org/10.1002/joc.5468 2024-09-17T04:49:23Z The value added from dynamic downscaling in climate projections of extratropical cyclones over the southwestern South Atlantic Ocean (SAO) is evaluated. For this purpose, the Regional Climate Model version 4 (RegCM4) is nested in the Hadley Global Environment Model 2 ‐ Earth System (HadGEM2‐ES) global climate model under the RCP8.5 scenario. The analyses focus on three time slices: the present (1979–2005), near future (NF: 2020–2050) and far future (FF: 2070–2098) climates. The cyclone tracking used an algorithm that searches for minima of relative vorticity at 925 hPa. Simulations of the present climate are compared to data from an ensemble of five reanalyses (ERA‐40, ERA‐Interim, NCEP‐NCAR, NCEP‐DOE and CFSR). For present climate, there is good agreement among reanalyses and models in associating austral winter and summer with higher and lower cyclone frequency, respectively. In addition, the simulations present the mean features of the cyclones (lifetime, distance travelled and mean velocity) as similar to those of the reanalysis. Moreover, RegCM4 outperforms the HadGEM2‐ES by simulating more realistically the spatial pattern of the cyclogenesis density over the SAO, which indicates value added from the RegCM4 downscaling. For the future climates, a decrease is projected for the annual frequency of cyclones, which reaches −6.5% (−3.6%) in RegCM4 (HadGEM2‐ES) in the NF and −11.4% (−10.4%) in the FF. Future projections do not indicate changes in the mean intensity of the cyclones. The negative trend of the cyclone frequency affects the precipitation. For FF, a decrease of approximately 15% in the precipitation associated with cyclones is projected. Article in Journal/Newspaper South Atlantic Ocean Wiley Online Library Austral International Journal of Climatology 38 6 2866 2879 |
institution |
Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
The value added from dynamic downscaling in climate projections of extratropical cyclones over the southwestern South Atlantic Ocean (SAO) is evaluated. For this purpose, the Regional Climate Model version 4 (RegCM4) is nested in the Hadley Global Environment Model 2 ‐ Earth System (HadGEM2‐ES) global climate model under the RCP8.5 scenario. The analyses focus on three time slices: the present (1979–2005), near future (NF: 2020–2050) and far future (FF: 2070–2098) climates. The cyclone tracking used an algorithm that searches for minima of relative vorticity at 925 hPa. Simulations of the present climate are compared to data from an ensemble of five reanalyses (ERA‐40, ERA‐Interim, NCEP‐NCAR, NCEP‐DOE and CFSR). For present climate, there is good agreement among reanalyses and models in associating austral winter and summer with higher and lower cyclone frequency, respectively. In addition, the simulations present the mean features of the cyclones (lifetime, distance travelled and mean velocity) as similar to those of the reanalysis. Moreover, RegCM4 outperforms the HadGEM2‐ES by simulating more realistically the spatial pattern of the cyclogenesis density over the SAO, which indicates value added from the RegCM4 downscaling. For the future climates, a decrease is projected for the annual frequency of cyclones, which reaches −6.5% (−3.6%) in RegCM4 (HadGEM2‐ES) in the NF and −11.4% (−10.4%) in the FF. Future projections do not indicate changes in the mean intensity of the cyclones. The negative trend of the cyclone frequency affects the precipitation. For FF, a decrease of approximately 15% in the precipitation associated with cyclones is projected. |
author2 |
Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Fundação de Amparo à Pesquisa do Estado de São Paulo Conselho Nacional de Desenvolvimento Científico e Tecnológico |
format |
Article in Journal/Newspaper |
author |
Reboita, Michelle S. da Rocha, Rosmeri P. de Souza, Marcelo R. Llopart, Marta |
spellingShingle |
Reboita, Michelle S. da Rocha, Rosmeri P. de Souza, Marcelo R. Llopart, Marta Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
author_facet |
Reboita, Michelle S. da Rocha, Rosmeri P. de Souza, Marcelo R. Llopart, Marta |
author_sort |
Reboita, Michelle S. |
title |
Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
title_short |
Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
title_full |
Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
title_fullStr |
Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
title_full_unstemmed |
Extratropical cyclones over the southwestern South Atlantic Ocean: HadGEM2‐ES and RegCM4 projections |
title_sort |
extratropical cyclones over the southwestern south atlantic ocean: hadgem2‐es and regcm4 projections |
publisher |
Wiley |
publishDate |
2018 |
url |
http://dx.doi.org/10.1002/joc.5468 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.5468 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.5468 |
geographic |
Austral |
geographic_facet |
Austral |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_source |
International Journal of Climatology volume 38, issue 6, page 2866-2879 ISSN 0899-8418 1097-0088 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/joc.5468 |
container_title |
International Journal of Climatology |
container_volume |
38 |
container_issue |
6 |
container_start_page |
2866 |
op_container_end_page |
2879 |
_version_ |
1812818276495917056 |