Direct SW aerosol radiative forcing over Portugal
In this work, the evaluation of the aerosol radiative forcing at the top of the atmosphere as well as at the surface over the south of Portugal is made, particularly in the regions of Évora (38°34' N, 7°54' W) and of Cabo da Roca (38°46' N, 9°38' W), during years 2004 and 2005. T...
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ftunivevora:oai:dspace.uevora.pt:10174/5459 2023-09-05T13:11:18+02:00 Direct SW aerosol radiative forcing over Portugal Santos, Dina Costa, Maria João Silva, Ana Maria 2008-10-02 http://hdl.handle.net/10174/5459 https://doi.org/10.5194/acp-8-5771-2008 eng eng Copernicus Publications Santos, D., Costa, M. J., and Silva, A. M.: Direct SW aerosol radiative forcing over Portugal, Atmos. Chem. Phys., 8, 5771-5786, doi:10.5194/acp-8-5771-2008, 2008. http://hdl.handle.net/10174/5459 FIS - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica dinas@uevora.pt mjcosta@uevora.pt asilva@uevora.pt 244 doi:10.5194/acp-8-5771-2008 restrictedAccess Aerosols Radiative forcing article 2008 ftunivevora https://doi.org/10.5194/acp-8-5771-2008 2023-08-14T17:29:06Z In this work, the evaluation of the aerosol radiative forcing at the top of the atmosphere as well as at the surface over the south of Portugal is made, particularly in the regions of Évora (38°34' N, 7°54' W) and of Cabo da Roca (38°46' N, 9°38' W), during years 2004 and 2005. The radiative transfer calculations, using the radiative transfer code Second Simulation of the Satellite Signal in the Solar Spectrum (6S), combine ground-based measurements, from Aerosol Robotic NETwork (AERONET), and satellite measurements, from MODerate Imaging Spectroradiometer (MODIS), to estimate the direct SW aerosol radiative forcing. The method developed to retrieve the surface spectral reflectance is also presented, based on ground-based measurements (AERONET) of the aerosol optical properties combined with the satellite-measured radiances (MODIS). The instantaneous direct SW aerosol radiative forcing values obtained at the top of the atmosphere are, in the majority of the cases, negative, indicating a tendency for cooling the Earth at the top of the atmosphere. For Desert Dust aerosols, over the Évora land region, the average forcing efficiency is estimated to be −25 Wm−2/AOT0.55 whereas for the Cabo da Roca area, the average forcing efficiency is −46 Wm−2/AOT0.55. In the presence of Forest Fire aerosols, both from short and long distances, the average value of forcing efficiency at the top of the atmosphere over Cabo da Roca is found to be −28 Wm−2/AOT0.55 and, over Évora, −27 Wm−2/AOT0.55. For specific situations, discussed in this work, the average surface direct SW aerosol radiative forcing efficiency due to the Desert Dust aerosols, in Évora region, is −66 Wm−2/AOT0.55, whereas in Cabo da Roca region, the corresponding average value is −38 Wm−2/AOT0.55. Considering the Forest Fire aerosols, over Évora region, the average surface direct SW aerosol radiative forcing efficiency can vary between −36 and −113 Wm−2/AOT0.55, the more negative value corresponding to forest fire aerosols coming only from shorter distances. Article in Journal/Newspaper Aerosol Robotic Network Repositório Científico da Universidade de Évora Roca ENVELOPE(-44.817,-44.817,-60.733,-60.733) Atmospheric Chemistry and Physics 8 19 5771 5786 |
institution |
Open Polar |
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Repositório Científico da Universidade de Évora |
op_collection_id |
ftunivevora |
language |
English |
topic |
Aerosols Radiative forcing |
spellingShingle |
Aerosols Radiative forcing Santos, Dina Costa, Maria João Silva, Ana Maria Direct SW aerosol radiative forcing over Portugal |
topic_facet |
Aerosols Radiative forcing |
description |
In this work, the evaluation of the aerosol radiative forcing at the top of the atmosphere as well as at the surface over the south of Portugal is made, particularly in the regions of Évora (38°34' N, 7°54' W) and of Cabo da Roca (38°46' N, 9°38' W), during years 2004 and 2005. The radiative transfer calculations, using the radiative transfer code Second Simulation of the Satellite Signal in the Solar Spectrum (6S), combine ground-based measurements, from Aerosol Robotic NETwork (AERONET), and satellite measurements, from MODerate Imaging Spectroradiometer (MODIS), to estimate the direct SW aerosol radiative forcing. The method developed to retrieve the surface spectral reflectance is also presented, based on ground-based measurements (AERONET) of the aerosol optical properties combined with the satellite-measured radiances (MODIS). The instantaneous direct SW aerosol radiative forcing values obtained at the top of the atmosphere are, in the majority of the cases, negative, indicating a tendency for cooling the Earth at the top of the atmosphere. For Desert Dust aerosols, over the Évora land region, the average forcing efficiency is estimated to be −25 Wm−2/AOT0.55 whereas for the Cabo da Roca area, the average forcing efficiency is −46 Wm−2/AOT0.55. In the presence of Forest Fire aerosols, both from short and long distances, the average value of forcing efficiency at the top of the atmosphere over Cabo da Roca is found to be −28 Wm−2/AOT0.55 and, over Évora, −27 Wm−2/AOT0.55. For specific situations, discussed in this work, the average surface direct SW aerosol radiative forcing efficiency due to the Desert Dust aerosols, in Évora region, is −66 Wm−2/AOT0.55, whereas in Cabo da Roca region, the corresponding average value is −38 Wm−2/AOT0.55. Considering the Forest Fire aerosols, over Évora region, the average surface direct SW aerosol radiative forcing efficiency can vary between −36 and −113 Wm−2/AOT0.55, the more negative value corresponding to forest fire aerosols coming only from shorter distances. |
format |
Article in Journal/Newspaper |
author |
Santos, Dina Costa, Maria João Silva, Ana Maria |
author_facet |
Santos, Dina Costa, Maria João Silva, Ana Maria |
author_sort |
Santos, Dina |
title |
Direct SW aerosol radiative forcing over Portugal |
title_short |
Direct SW aerosol radiative forcing over Portugal |
title_full |
Direct SW aerosol radiative forcing over Portugal |
title_fullStr |
Direct SW aerosol radiative forcing over Portugal |
title_full_unstemmed |
Direct SW aerosol radiative forcing over Portugal |
title_sort |
direct sw aerosol radiative forcing over portugal |
publisher |
Copernicus Publications |
publishDate |
2008 |
url |
http://hdl.handle.net/10174/5459 https://doi.org/10.5194/acp-8-5771-2008 |
long_lat |
ENVELOPE(-44.817,-44.817,-60.733,-60.733) |
geographic |
Roca |
geographic_facet |
Roca |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_relation |
Santos, D., Costa, M. J., and Silva, A. M.: Direct SW aerosol radiative forcing over Portugal, Atmos. Chem. Phys., 8, 5771-5786, doi:10.5194/acp-8-5771-2008, 2008. http://hdl.handle.net/10174/5459 FIS - Publicações - Artigos em Revistas Internacionais Com Arbitragem Científica dinas@uevora.pt mjcosta@uevora.pt asilva@uevora.pt 244 doi:10.5194/acp-8-5771-2008 |
op_rights |
restrictedAccess |
op_doi |
https://doi.org/10.5194/acp-8-5771-2008 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
8 |
container_issue |
19 |
container_start_page |
5771 |
op_container_end_page |
5786 |
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1776202938515980288 |