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| Titel |
The decreasing albedo of the Zhadang glacier on western Nyainqentanglha and the role of light-absorbing impurities |
| VerfasserIn |
B. Qu, J. Ming, S.-C. Kang, G.-S. Zhang, Y.-W. Li, C.-D. Li, S.-Y. Zhao, Z.-M. Ji, J.-J. Cao |
| 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. 20 ; Nr. 14, no. 20 (2014-10-22), S.11117-11128 |
| Datensatznummer |
250119113
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| Publikation (Nr.) |
 copernicus.org/acp-14-11117-2014.pdf |
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| Zusammenfassung |
| A large change in albedo has a significant effect on glacier ablation.
Atmospheric aerosols – e.g. black carbon (BC) and dust – can reduce the
albedo of glaciers and thus contribute to their melting. In this study, two
main themes were explored: (1) the decrease in albedo of the Zhadang glacier
on Mt. Nyainqentanglha between 2001 and 2012, as observed by the Moderate
Resolution Imaging Spectroradiometer (MODIS) on-board the Terra satellite,
and the correlation of this albedo with mass balance; and (2) the
concentrations of BC and dust in the glacier measured during 2012, and the
associated impacts of these impurities on albedo and radiative forcings
(RF). The average albedo of the Zhadang glacier from the MODIS increased
with the altitude and fluctuated but had a decreasing trend (−0.003 a−1) during the
period 2001–2012, with the highest (0.722) in 2003 and the lowest (0.597)
in 2009 and 2010. The mass balance of the glacier has a positively
significant correlation with its surface albedo derived from MODIS. Snow
samples were collected on the Zhadang glacier to measure the BC and dust in
the summer of 2012. The impacts of BC and dust on albedo reduction in
different melting conditions were identified with the SNow ICe Aerosol
Radiative (SNICAR) model initiated by in situ observation data. The
sensitivity analysis showed that BC was a major factor in albedo reduction
when the glacier was covered by newly fallen snow. Nevertheless, the
contribution of dust to albedo reduction can reach as high as 56%, much
exceeding that of BC (28%), when the glacier experiences strong surficial
melting and its surface is almost bare ice. The average RF caused by dust
could increase from 1.1 to 8.6 W m−2, exceeding the RF caused by BC
after snow was deposited and surface melting occurred in the Zhadang
glacier. This implies that it may be dust that primarily dominates the
melting of some glaciers in the inner Tibetan Plateau during melting seasons, rather than
BC. |
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