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Titel |
Snow cover sensitivity to black carbon deposition in the Himalayas: from atmospheric and ice core measurements to regional climate simulations |
VerfasserIn |
M. Ménégoz, G. Krinner, Y. Balkanski, O. Boucher, A. Cozic, S. Lim, P. Ginot, P. Laj, H. Gallée, P. Wagnon, A. Marinoni, H. W. Jacobi |
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. 8 ; Nr. 14, no. 8 (2014-04-28), S.4237-4249 |
Datensatznummer |
250118643
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Publikation (Nr.) |
copernicus.org/acp-14-4237-2014.pdf |
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Zusammenfassung |
We applied a climate-chemistry global model to evaluate the impact of black
carbon (BC) deposition on the Himalayan snow cover from 1998 to 2008. Using
a stretched grid with a resolution of 50 km over this complex topography,
the model reproduces reasonably well the remotely sensed observations of the
snow cover duration. Similar to observations, modelled atmospheric BC
concentrations in the central Himalayas reach a minimum during the monsoon and a
maximum during the post- and pre-monsoon periods. Comparing the simulated BC
concentrations in the snow with observations is more challenging because of
their high spatial variability and complex vertical distribution. We
simulated spring BC concentrations in surface snow varying from tens to
hundreds of μg kg−1, higher by one to two orders of magnitude
than those observed in ice cores extracted from central Himalayan glaciers
at high elevations (>6000 m a.s.l.), but typical for seasonal
snow cover sampled in middle elevation regions (<6000 m a.s.l.). In
these areas, we estimate that both wet and dry BC depositions affect the
Himalayan snow cover reducing its annual duration by 1 to 8 days.
In our simulations, the effect of anthropogenic BC deposition on snow
is quite low over the Tibetan Plateau because this area is only sparsely
snow covered. However, the impact becomes larger along the entire
Hindu-Kush, Karakorum and Himalayan mountain ranges. In these regions, BC in
snow induces an increase of the net short-wave radiation at the surface with
an annual mean of 1 to 3 W m−2 leading to a localised warming between
0.05 and 0.3 °C. |
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