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Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model

The simulation of Sahel rainfall and its onset during the West African Monsoon (WAM) remains a challenge for current state-of-the-art climate models due to their persistent biases, especially in the tropical Atlantic region. Here we show that improved representation of Atlantic Cold Tongue (ACT) dev...

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Autores principales: Steinig, S., Harlaß, J., Park, W., Latif, M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803197/
https://www.ncbi.nlm.nih.gov/pubmed/29416079
http://dx.doi.org/10.1038/s41598-018-20904-1
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author Steinig, S.
Harlaß, J.
Park, W.
Latif, M.
author_facet Steinig, S.
Harlaß, J.
Park, W.
Latif, M.
author_sort Steinig, S.
collection PubMed
description The simulation of Sahel rainfall and its onset during the West African Monsoon (WAM) remains a challenge for current state-of-the-art climate models due to their persistent biases, especially in the tropical Atlantic region. Here we show that improved representation of Atlantic Cold Tongue (ACT) development is essential for a more realistic seasonal evolution of the WAM, which is due to a further inland migration of the precipitation maximum. The observed marked relationship between ACT development and Sahel rainfall onset only can be reproduced by a climate model, the Kiel Climate Model (KCM), when sufficiently high resolution in its atmospheric component is employed, enabling enhanced equatorial Atlantic interannual sea surface temperature variability in the ACT region relative to versions with coarser atmospheric resolution. The ACT/Sahel rainfall relationship in the model critically depends on the correct seasonal phase-locking of the interannual variability rather than on its magnitude. We compare the KCM results with those obtained from climate models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5).
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spelling pubmed-58031972018-02-14 Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model Steinig, S. Harlaß, J. Park, W. Latif, M. Sci Rep Article The simulation of Sahel rainfall and its onset during the West African Monsoon (WAM) remains a challenge for current state-of-the-art climate models due to their persistent biases, especially in the tropical Atlantic region. Here we show that improved representation of Atlantic Cold Tongue (ACT) development is essential for a more realistic seasonal evolution of the WAM, which is due to a further inland migration of the precipitation maximum. The observed marked relationship between ACT development and Sahel rainfall onset only can be reproduced by a climate model, the Kiel Climate Model (KCM), when sufficiently high resolution in its atmospheric component is employed, enabling enhanced equatorial Atlantic interannual sea surface temperature variability in the ACT region relative to versions with coarser atmospheric resolution. The ACT/Sahel rainfall relationship in the model critically depends on the correct seasonal phase-locking of the interannual variability rather than on its magnitude. We compare the KCM results with those obtained from climate models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5). Nature Publishing Group UK 2018-02-07 /pmc/articles/PMC5803197/ /pubmed/29416079 http://dx.doi.org/10.1038/s41598-018-20904-1 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Steinig, S.
Harlaß, J.
Park, W.
Latif, M.
Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title_full Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title_fullStr Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title_full_unstemmed Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title_short Sahel rainfall strength and onset improvements due to more realistic Atlantic cold tongue development in a climate model
title_sort sahel rainfall strength and onset improvements due to more realistic atlantic cold tongue development in a climate model
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5803197/
https://www.ncbi.nlm.nih.gov/pubmed/29416079
http://dx.doi.org/10.1038/s41598-018-20904-1
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