Title:
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Dust aerosol radiative effects during summer 2012 simulated with a coupled regional aerosol–atmosphere–ocean model over the Mediterranean
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Author:
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Nabat, Pierre; Somot, S; Mallet, Marc; Michou, M; Sevault, F; Driouech, F; Meloni, D; di Sarra, G; di Biagio, C; Formenti, P; Sicard, Michaël; Leon, JF; Bouin, MN
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions; Universitat Politècnica de Catalunya. RSLAB - Grup de Recerca en Teledetecció |
Abstract:
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The present study investigates the effects of aerosols on the Mediterranean climate daily variability during summer 2012. Simulations have been carried out using the coupled regional climate system model CNRM-RCSM5 which includes prognostic aerosols, namely desert dust, sea salt, organic, black-carbon and sulfate particles, in addition to the atmosphere, land surface and ocean components. An evaluation of the dust aerosol scheme of CNRM-RCSM5 has been performed against in-situ and satellite
measurements. This scheme shows its ability to reproduce the spatial and temporal variability of aerosol optical depth (AOD) over the Mediterranean region in summer 2012. Observations from the TRAQA/ChArMEx campaign also show that the model
correctly represents dust vertical and size distributions. Thus CNRM-RCSM5 can be used for aerosol–climate studies over the Mediterranean. Here we focus on the effects of dust particles on surface temperature and radiation daily variability. Surface shortwave
aerosol radiative forcing variability is found to be more than twice higher over regions affected by dust aerosols, when using a prognostic aerosol scheme instead of a monthly climatology. In this case downward surface solar radiation is also found to be better reproduced according to a comparison with several stations across the
Mediterranean. Moreover, the radiative forcing due to the dust outbreaks also causes an extra cooling in land and sea surface temperatures. A composite study has been carried out for 14 stations across the Mediterranean to identify more precisely the differences
between dusty days and the set of all the days. Observations show that dusty days receive less radiation at the surface and are warmer than average because of southwesterly fluxes often generating dust outbreaks. Only the simulation using the prognostic aerosol scheme is found to reproduce the observed intensity of the dimming and warming on dusty days. Otherwise, the dimming is underestimated and the warming overestimated. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Degradació ambiental::Contaminació atmosfèrica -Àrees temàtiques de la UPC::Enginyeria agroalimentària::Ciències de la terra i de la vida -Air -- Pollution -- Meteorological aspects -Earth sciences -Aerosol radiative effect -Comparison observations-model -Aire -- Contaminació -- Aspectes meteorològics -Ciències de la terra |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Article |
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