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| Titel |
Numerical simulation of extreme snowmelt observed at the SIGMA-A site, northwest Greenland, during summer 2012 |
| VerfasserIn |
M. Niwano, T. Aoki, S. Matoba, S. Yamaguchi, T. Tanikawa, K. Kuchiki, H. Motoyama |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 3 ; Nr. 9, no. 3 (2015-05-11), S.971-988 |
| Datensatznummer |
250116796
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| Publikation (Nr.) |
 copernicus.org/tc-9-971-2015.pdf |
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| Zusammenfassung |
| The surface energy balance (SEB) from 30 June to 14 July 2012 at
site SIGMA (Snow Impurity and Glacial Microbe effects on abrupt
warming in the Arctic)-A, (78°03' N,
67°38' W; 1490 m a.s.l.) on the
northwest Greenland Ice Sheet (GrIS) was investigated by using in
situ atmospheric and snow measurements as well as numerical
modeling with a one-dimensional multi-layered physical snowpack
model called SMAP (Snow Metamorphism and Albedo Process). At
SIGMA-A, remarkable near-surface snowmelt and continuous heavy
rainfall (accumulated precipitation between 10 and 14 July was
estimated to be 100 mm) were observed after 10 July 2012.
Application of the SMAP model to the GrIS snowpack was
evaluated based on the snow temperature profile, snow surface
temperature, surface snow grain size, and shortwave albedo, all of
which the model simulated reasonably well. Above all,
the fact that the SMAP model successfully
reproduced frequently observed rapid increases in snow albedo under
cloudy conditions highlights the advantage of the
physically based snow albedo model (PBSAM) incorporated
in the SMAP model.
Using such data and model, we estimated the
SEB at SIGMA-A from 30 June to 14 July 2012. Radiation-related
fluxes were obtained from in situ measurements, whereas other fluxes
were calculated with the SMAP model. By examining the components of
the SEB, we determined that low-level clouds accompanied by
a significant temperature increase played an important role in the
melt event observed at SIGMA-A. These conditions induced
a remarkable surface heating via cloud radiative forcing in the polar region. |
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