Better representation of dust can improve climate models with too weak an African monsoon

<p>The amount of short wave radiation absorbed by dust has remained uncertain. We have developed a more accurate representation of dust absorption that is based on the observed dust mineralogical composition and accounts for very large particles. We analyze the results from two fully coupled c...

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Main Authors: Y. Balkanski, R. Bonnet, O. Boucher, R. Checa-Garcia, J. Servonnat
Format: Article
Language:English
Published: Copernicus Publications 2021-07-01
Series:Atmospheric Chemistry and Physics
Online Access:https://acp.copernicus.org/articles/21/11423/2021/acp-21-11423-2021.pdf
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author Y. Balkanski
R. Bonnet
O. Boucher
R. Checa-Garcia
J. Servonnat
author_facet Y. Balkanski
R. Bonnet
O. Boucher
R. Checa-Garcia
J. Servonnat
author_sort Y. Balkanski
collection DOAJ
description <p>The amount of short wave radiation absorbed by dust has remained uncertain. We have developed a more accurate representation of dust absorption that is based on the observed dust mineralogical composition and accounts for very large particles. We analyze the results from two fully coupled climate simulations of 100 years in terms of their simulated precipitation patterns against observations. A striking benefit of the new dust optical and physical properties is that tropical precipitation over the Sahel, tropical North Atlantic and West Indian Ocean are significantly improved compared to observations, without degrading precipitations elsewhere. This alleviates a common persistent bias in Earth system models that exhibit a summer African monsoon that does not reach far enough north. We show that the improvements documented here for the IPSL-CM6<span class="note-anchor" id="fna_Ch1.Footn1"><a href="#fn_Ch1.Footn1"><sup>1</sup></a></span> climate model result from both a thermodynamical and dynamical response to dust absorption, which is unrelated to natural variability. Aerosol absorption induces more water vapor advection from the ocean to the Sahel region, thereby providing an added supply of moisture available for precipitation. This work, thus, provides a path towards improving precipitation patterns in these regions by accounting for both physical and optical properties of the aerosol more realistically.</p>
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spelling doaj.art-a89f8f4a0b064923b52052c8f3cb6bd92022-12-21T18:48:24ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242021-07-0121114231143510.5194/acp-21-11423-2021Better representation of dust can improve climate models with too weak an African monsoonY. Balkanski0R. Bonnet1O. Boucher2R. Checa-Garcia3J. Servonnat4Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, IPSL, Gif-sur-Yvette, FranceInstitut Pierre-Simon Laplace, Sorbonne Université-CNRS, Paris, FranceInstitut Pierre-Simon Laplace, Sorbonne Université-CNRS, Paris, FranceLaboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, IPSL, Gif-sur-Yvette, FranceLaboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, IPSL, Gif-sur-Yvette, France<p>The amount of short wave radiation absorbed by dust has remained uncertain. We have developed a more accurate representation of dust absorption that is based on the observed dust mineralogical composition and accounts for very large particles. We analyze the results from two fully coupled climate simulations of 100 years in terms of their simulated precipitation patterns against observations. A striking benefit of the new dust optical and physical properties is that tropical precipitation over the Sahel, tropical North Atlantic and West Indian Ocean are significantly improved compared to observations, without degrading precipitations elsewhere. This alleviates a common persistent bias in Earth system models that exhibit a summer African monsoon that does not reach far enough north. We show that the improvements documented here for the IPSL-CM6<span class="note-anchor" id="fna_Ch1.Footn1"><a href="#fn_Ch1.Footn1"><sup>1</sup></a></span> climate model result from both a thermodynamical and dynamical response to dust absorption, which is unrelated to natural variability. Aerosol absorption induces more water vapor advection from the ocean to the Sahel region, thereby providing an added supply of moisture available for precipitation. This work, thus, provides a path towards improving precipitation patterns in these regions by accounting for both physical and optical properties of the aerosol more realistically.</p>https://acp.copernicus.org/articles/21/11423/2021/acp-21-11423-2021.pdf
spellingShingle Y. Balkanski
R. Bonnet
O. Boucher
R. Checa-Garcia
J. Servonnat
Better representation of dust can improve climate models with too weak an African monsoon
Atmospheric Chemistry and Physics
title Better representation of dust can improve climate models with too weak an African monsoon
title_full Better representation of dust can improve climate models with too weak an African monsoon
title_fullStr Better representation of dust can improve climate models with too weak an African monsoon
title_full_unstemmed Better representation of dust can improve climate models with too weak an African monsoon
title_short Better representation of dust can improve climate models with too weak an African monsoon
title_sort better representation of dust can improve climate models with too weak an african monsoon
url https://acp.copernicus.org/articles/21/11423/2021/acp-21-11423-2021.pdf
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