Titre :

Direct and semi-direct radiative forcing of biomass-burning aerosols over the southeast Atlantic (SEA) and its sensitivity to absorbing properties: a regional climate modeling study

Auteur(s) :

Mallet, Marc [Auteur]
Centre national de recherches météorologiques [CNRM]
Solmon, Fabien [Auteur]
Laboratoire d'aérologie [LAERO]
Nabat, Pierre [Auteur]
Centre national de recherches météorologiques [CNRM]
Elguindi, Nellie [Auteur]
Laboratoire d'aérologie [LAERO]
Waquet, Fabien [Auteur]
Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518
Bouniol, Dominique [Auteur]
Centre national de recherches météorologiques [CNRM]
Sayer, Andrew Mark [Auteur]
NASA Goddard Space Flight Center [GSFC]
Universities Space Research Association [Washington] [USRA]
Meyer, Kerry [Auteur]
NASA Goddard Space Flight Center [GSFC]
Roehrig, Romain [Auteur]
Centre national de recherches météorologiques [CNRM]
Michou, Martine [Auteur]
Centre national de recherches météorologiques [CNRM]
Zuidema, Paquita [Auteur]
Rosenstiel School of Marine and Atmospheric Science [RSMAS]
Flamant, Cyrille [Auteur]
Laboratoire Atmosphères, Milieux, Observations Spatiales [LATMOS]
Redemann, Jens [Auteur]
University of Oklahoma [OU]
Formenti, Paola [Auteur]
Laboratoire Interuniversitaire des Systèmes Atmosphériques [LISA (UMR_7583)]

Titre de la revue :

Atmos. Chem. Phys.

Numéro :

20

Pagination :

-

Date de publication :

2021-03-10

ISSN :

1680-7316

Résumé en anglais : [en]

Simulations are performed for the period 2000–2015 by two different regional climate models, ALADIN–Climat and RegCM, to quantify the direct and semi-direct radiative effects of biomass burning aerosols (BBA) in the Southeast ...
Lire la suite >Simulations are performed for the period 2000–2015 by two different regional climate models, ALADIN–Climat and RegCM, to quantify the direct and semi-direct radiative effects of biomass burning aerosols (BBA) in the Southeast Atlantic (SEA) region. The approach of using two different independent RCMs reinforces the robustness of the results. Different simulations have been performed using strongly absorbing BBA in accordance with recent in situ observations over the SEA. For the July–August–September (JAS) season, the single scattering albedo (SSA) and total aerosol optical depth (AOD) simulated by the ALADIN–Climat and RegCM models are consistent with the MACv2 climatology and MERRA-2 and CAMS-RA reanalyses near the biomass burning emission sources. However, the above-cloud AOD is slightly underestimated compared to satellite (MODIS and POLDER) data during the transport over the SEA. The direct radiative effect exerted at the continental and oceanic surfaces by BBA is significant in both models and the radiative effects at the top of the atmosphere indicate a remarkable regional contrast over SEA (in all-sky conditions), with a cooling (warming) north (south) of 10° S, which is in agreement with the recent MACv2 climatology. In addition, the two models indicate that BBA are responsible for an important shortwave radiative heating of ~ 0.5–1 K per day over SEA during JAS with maxima between 2 and 4 km above mean sea-level. At these altitudes, BBA increase air temperature by ~ 0.2–0.5 K, with the highest values being co-located with low stratocumulus clouds. Vertical changes in air temperature limit the subsidence over SEA creating a cyclonic anomaly. The opposite effect is simulated over the continent due to the increase in lower troposphere stability. The BBA semi-direct effect on the lower troposphere circulation is found to be consistent between the two models. Changes in the cloud fraction are moderate in response to the presence of smoke and the models differ over the Gulf of Guinea. Finally, the results indicate an important sensitivity of the direct and semi-direct effects to the absorbing properties of BBA.Lire moins >

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS

Collections :

• Laboratoire d'Optique Atmosphérique (LOA) - UMR 8518

Date de dépôt :

2024-01-16T22:13:44Z
2024-02-09T10:52:25Z