Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability
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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ftnasantrs:oai:casi.ntrs.nasa.gov:20170003432 2023-05-15T17:29:53+02:00 Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability Yu, Hongbin Chin, Mian Yuan, Tianle Platnick, Steven Meyer, Kerry Zelinka, Mark Norris, Joel R. Oraiopoulos, Lazaros Unclassified, Unlimited, Publicly available February 4, 2016 application/pdf http://hdl.handle.net/2060/20170003432 unknown Document ID: 20170003432 http://hdl.handle.net/2060/20170003432 Copyright, Distribution as joint owner in the copyright CASI Statistics and Probability Meteorology and Climatology GSFC-E-DAA-TN41116 Geophysical Research Letters (ISSN 0094-8276) (e-ISSN 1944-8007); 43; 3; 1349-1356 2016 ftnasantrs 2019-07-20T23:35:40Z 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. Other/Unknown Material North Atlantic NASA Technical Reports Server (NTRS) |
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Open Polar |
collection |
NASA Technical Reports Server (NTRS) |
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ftnasantrs |
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topic |
Statistics and Probability Meteorology and Climatology |
spellingShingle |
Statistics and Probability Meteorology and Climatology Yu, Hongbin Chin, Mian Yuan, Tianle Platnick, Steven Meyer, Kerry Zelinka, Mark Norris, Joel R. Oraiopoulos, Lazaros Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
topic_facet |
Statistics and Probability Meteorology and Climatology |
description |
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 |
Other/Unknown Material |
author |
Yu, Hongbin Chin, Mian Yuan, Tianle Platnick, Steven Meyer, Kerry Zelinka, Mark Norris, Joel R. Oraiopoulos, Lazaros |
author_facet |
Yu, Hongbin Chin, Mian Yuan, Tianle Platnick, Steven Meyer, Kerry Zelinka, Mark Norris, Joel R. Oraiopoulos, Lazaros |
author_sort |
Yu, Hongbin |
title |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
title_short |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
title_full |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
title_fullStr |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
title_full_unstemmed |
Positive Low Cloud and Dust Feedbacks Amplify Tropical North Atlantic Multidecadal Variability |
title_sort |
positive low cloud and dust feedbacks amplify tropical north atlantic multidecadal variability |
publishDate |
2016 |
url |
http://hdl.handle.net/2060/20170003432 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
CASI |
op_relation |
Document ID: 20170003432 http://hdl.handle.net/2060/20170003432 |
op_rights |
Copyright, Distribution as joint owner in the copyright |
_version_ |
1766125112778555392 |