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Titel |
Aerosol variability and atmospheric transport in the Himalayan region from CALIOP 2007-2010 observations |
VerfasserIn |
S. Bucci, C. Cagnazzo, F. Cairo, L. Di Liberto, F. Fierli |
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. 9 ; Nr. 14, no. 9 (2014-05-05), S.4369-4381 |
Datensatznummer |
250118677
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Publikation (Nr.) |
copernicus.org/acp-14-4369-2014.pdf |
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Zusammenfassung |
This work quantifies the spatial distribution of different aerosol types,
their seasonal variability and sources.The analysis of four years of CALIOP
(Cloud–Aerosol LIdar with Orthogonal Polarization) vertically resolved aerosol data allows the identification of spatial
patterns of desert dust and carbonaceous particles in different atmospheric
layers. Clusters of Lagrangian back trajectories highlight the transport
pathways from source regions during the dusty spring season. The analysis
shows a prevalence of dust; at low heights it occurs frequently (up to 70%
of available observations) and is distributed north of the Tibetan Plateau
with a main contribution from the Gobi and Taklamakan deserts, and west of
the Tibetan Plateau, originating from the deserts of southwest Asia and
advected by the Westerlies. Above the Himalayas the dust amount is minor but
still not negligible (occurrence around 20%) and mainly affected by the
transport from more distant deserts sources (Sahara and Arabian Peninsula).
Carbonaceous aerosol, produced mainly in northern India and eastern China, is
subject to shorter-range transport and is indeed observed closer to the
sources, while there is a limited amount reaching the top of the plateau. Data
analysis reveals a clear seasonal variability in the frequencies of
occurrence for the main aerosol types; dust is regulated principally by the
monsoon dynamics, with maximal occurrence in spring. We also highlight
relevant interannual differences, showing a larger presence of aerosol in the
region during 2007 and 2008. The characterization of the aerosol spatial and
temporal distribution in terms of observational frequency is a key piece of
information that can be directly used for the evaluation of global aerosol
models. |
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