Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation
The Atlantic Multidecadal Oscillation (AMO) is characterized by a horseshoe pattern of sea surface temperature (SST) anomalies and has a wide range of climatic impacts. While the tropical arm of AMO is responsible for many of these impacts, it is either too weak or completely absent in many climate...
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ftpubmed:oai:pubmedcentral.nih.gov:7430503 2023-05-15T17:29:55+02:00 Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation Yuan, Tianle Oreopoulos, Lazaros Zelinka, Mark Yu, Hongbin Norris, Joel R. Chin, Mian Platnick, Steven Meyer, Kerry 2016-01-16 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430503/ https://doi.org/10.1002/2016GL067679 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430503/ http://dx.doi.org/10.1002/2016GL067679 Geophys Res Lett Article Text 2016 ftpubmed https://doi.org/10.1002/2016GL067679 2020-08-23T00:35:04Z The Atlantic Multidecadal Oscillation (AMO) is characterized by a horseshoe pattern of sea surface temperature (SST) anomalies and has a wide range of climatic impacts. While the tropical arm of AMO is responsible for many of these impacts, it is either too weak or completely absent in many climate model simulations. Here we show, using both observational and model evidence, that the radiative effect of positive low cloud and dust feedbacks is strong enough to generate the tropical arm of AMO, with the low cloud feedback more dominant. The feedbacks can be understood in a consistent dynamical framework: weakened tropical trade wind speed in response to a warm middle latitude SST anomaly reduces dust loading and low cloud fraction over the tropical Atlantic, which warms the tropical North Atlantic SST. Together they contribute to appearance of the tropical arm of AMO. Most current climate models miss both the critical wind speed response and two positive feedbacks though realistic simulations of them may be essential for many climatic studies related to the AMO. Text North Atlantic PubMed Central (PMC) Geophysical Research Letters 43 3 1349 1356 |
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Article Yuan, Tianle Oreopoulos, Lazaros Zelinka, Mark Yu, Hongbin Norris, Joel R. Chin, Mian Platnick, Steven Meyer, Kerry Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
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The Atlantic Multidecadal Oscillation (AMO) is characterized by a horseshoe pattern of sea surface temperature (SST) anomalies and has a wide range of climatic impacts. While the tropical arm of AMO is responsible for many of these impacts, it is either too weak or completely absent in many climate model simulations. Here we show, using both observational and model evidence, that the radiative effect of positive low cloud and dust feedbacks is strong enough to generate the tropical arm of AMO, with the low cloud feedback more dominant. The feedbacks can be understood in a consistent dynamical framework: weakened tropical trade wind speed in response to a warm middle latitude SST anomaly reduces dust loading and low cloud fraction over the tropical Atlantic, which warms the tropical North Atlantic SST. Together they contribute to appearance of the tropical arm of AMO. Most current climate models miss both the critical wind speed response and two positive feedbacks though realistic simulations of them may be essential for many climatic studies related to the AMO. |
format |
Text |
author |
Yuan, Tianle Oreopoulos, Lazaros Zelinka, Mark Yu, Hongbin Norris, Joel R. Chin, Mian Platnick, Steven Meyer, Kerry |
author_facet |
Yuan, Tianle Oreopoulos, Lazaros Zelinka, Mark Yu, Hongbin Norris, Joel R. Chin, Mian Platnick, Steven Meyer, Kerry |
author_sort |
Yuan, Tianle |
title |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
title_short |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
title_full |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
title_fullStr |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
title_full_unstemmed |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Oscillation |
title_sort |
positive low cloud and dust feedbacks amplify tropical north atlantic multidecadal oscillation |
publishDate |
2016 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430503/ https://doi.org/10.1002/2016GL067679 |
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North Atlantic |
genre_facet |
North Atlantic |
op_source |
Geophys Res Lett |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430503/ http://dx.doi.org/10.1002/2016GL067679 |
op_doi |
https://doi.org/10.1002/2016GL067679 |
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Geophysical Research Letters |
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43 |
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3 |
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1349 |
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1356 |
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1766125150566088704 |