An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon
By analyzing observations and model simulations, here we show that there exists a significant anticorrelation on interannual to multidecadal time scales between the Sahel and southeast Amazon rainfall during July-August-September. This rainfall seesaw, which is strongest on decadal to multidecadal s...
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ftosti:oai:osti.gov:1611897 2023-07-30T04:05:15+02:00 An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon Hua, Wenjian Dai, Aiguo Zhou, Liming Qin, Minhua Chen, Haishan 2021-09-03 application/pdf http://www.osti.gov/servlets/purl/1611897 https://www.osti.gov/biblio/1611897 https://doi.org/10.1029/2018gl081406 unknown http://www.osti.gov/servlets/purl/1611897 https://www.osti.gov/biblio/1611897 https://doi.org/10.1029/2018gl081406 doi:10.1029/2018gl081406 58 GEOSCIENCES 2021 ftosti https://doi.org/10.1029/2018gl081406 2023-07-11T09:41:19Z By analyzing observations and model simulations, here we show that there exists a significant anticorrelation on interannual to multidecadal time scales between the Sahel and southeast Amazon rainfall during July-August-September. This rainfall seesaw, which is strongest on decadal to multidecadal scales, is due to an anomalous meridional gradient of sea surface temperatures across the tropical Atlantic that pushes the Intertropical Convergence Zone and its associated rain belt toward the anomalously warm hemisphere. Large ensemble model simulations suggest that the seesaw pattern is likely caused by decadal changes in anthropogenic and volcanic aerosols, rather than internal climate variability. Our results suggest that the recent decadal to multidecadal climate variations in and around the North Atlantic basin are largely externally forced and that projected large North Atlantic warming could lead to a wetter Sahel but drier Amazon in the future. Other/Unknown Material North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Geophysical Research Letters 46 2 923 932 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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58 GEOSCIENCES |
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58 GEOSCIENCES Hua, Wenjian Dai, Aiguo Zhou, Liming Qin, Minhua Chen, Haishan An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
topic_facet |
58 GEOSCIENCES |
description |
By analyzing observations and model simulations, here we show that there exists a significant anticorrelation on interannual to multidecadal time scales between the Sahel and southeast Amazon rainfall during July-August-September. This rainfall seesaw, which is strongest on decadal to multidecadal scales, is due to an anomalous meridional gradient of sea surface temperatures across the tropical Atlantic that pushes the Intertropical Convergence Zone and its associated rain belt toward the anomalously warm hemisphere. Large ensemble model simulations suggest that the seesaw pattern is likely caused by decadal changes in anthropogenic and volcanic aerosols, rather than internal climate variability. Our results suggest that the recent decadal to multidecadal climate variations in and around the North Atlantic basin are largely externally forced and that projected large North Atlantic warming could lead to a wetter Sahel but drier Amazon in the future. |
author |
Hua, Wenjian Dai, Aiguo Zhou, Liming Qin, Minhua Chen, Haishan |
author_facet |
Hua, Wenjian Dai, Aiguo Zhou, Liming Qin, Minhua Chen, Haishan |
author_sort |
Hua, Wenjian |
title |
An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
title_short |
An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
title_full |
An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
title_fullStr |
An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
title_full_unstemmed |
An Externally Forced Decadal Rainfall Seesaw Pattern Over the Sahel and Southeast Amazon |
title_sort |
externally forced decadal rainfall seesaw pattern over the sahel and southeast amazon |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1611897 https://www.osti.gov/biblio/1611897 https://doi.org/10.1029/2018gl081406 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/1611897 https://www.osti.gov/biblio/1611897 https://doi.org/10.1029/2018gl081406 doi:10.1029/2018gl081406 |
op_doi |
https://doi.org/10.1029/2018gl081406 |
container_title |
Geophysical Research Letters |
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46 |
container_issue |
2 |
container_start_page |
923 |
op_container_end_page |
932 |
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1772817039936716800 |