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| Titel |
Radiative signature of absorbing aerosol over the eastern Mediterranean basin |
| VerfasserIn |
A. K. Mishra, K. Klingmueller, E. Fredj, J. Lelieveld  , Y. Rudich, I. Koren |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 14 ; Nr. 14, no. 14 (2014-07-16), S.7213-7231 |
| Datensatznummer |
250118889
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| Publikation (Nr.) |
 copernicus.org/acp-14-7213-2014.pdf |
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| Zusammenfassung |
| The effects of absorbing aerosols on the atmospheric radiation budget and
dynamics over the eastern Mediterranean region are studied using satellites
and ground-based observations, and radiative transfer model calculations,
under summer conditions. Climatology of aerosol optical depth (AOD), single
scattering albedo (SSA) and size parameters were analyzed using multi-year
(1999–2012) observations from Moderate Resolution Imaging Spectroradiometer (MODIS),
Multi-angle Imaging SpectroRadiometer (MISR)
and AErosol RObotic NETwork (AERONET). Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP)-derived
aerosol vertical distributions and their classifications are used to
calculate the AOD of four dominant aerosol types: dust, polluted dust, polluted
continental, and marine aerosol over the region. The seasonal mean (June–August
2010) AODs are 0.22 ± 0.02, 0.11 ± 0.04, 0.10 ± 0.04
and 0.06 ± 0.01 for polluted dust, polluted continental, dust and
marine aerosol, respectively. Changes in the atmospheric temperature profile
as a function of absorbing aerosol loading were derived for the same period
using observations from the AIRS satellite. We inferred heating rates in the
aerosol layer of ~1.7 ± 0.8 K day−1 between 925
and 850 hPa, which is attributed to aerosol absorption of incoming solar
radiation. Radiative transfer model (RTM) calculations show significant
atmospheric warming for dominant absorbing aerosol over the region. A
maximum atmospheric forcing of +16.7 ± 7.9 Wm−2 is calculated
in the case of polluted dust, followed by dust (+9.4 ± 4.9 Wm−2)
and polluted continental (+6.4 ± 4.5 Wm−2). RTM-derived heating
rate profiles for dominant absorbing aerosol show warming of 0.1–0.9 K day−1 in the aerosol layer (< 3.0 km altitudes), which
primarily depend on AODs of the different aerosol types. Diabatic heating
due to absorbing aerosol stabilizes the lower atmosphere, which could
significantly reduce the atmospheric ventilation. These conditions can
enhance the "pollution pool" over the eastern Mediterranean. |
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