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| Titel |
Comparison of the meteorology and surface energy balance at Storbreen and Midtdalsbreen, two glaciers in southern Norway |
| VerfasserIn |
R. H. Giesen, L. M. Andreassen, M. R. Broeke, J. Oerlemans  |
| 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 ; 3, no. 1 ; Nr. 3, no. 1 (2009-03-20), S.57-74 |
| Datensatznummer |
250000785
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| Publikation (Nr.) |
 copernicus.org/tc-3-57-2009.pdf |
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| Zusammenfassung |
| We compare 5 years of meteorological records from automatic
weather stations (AWSs) on Storbreen and Midtdalsbreen, two glaciers
in southern Norway, located approximately 120 km apart. The records
are obtained from identical AWSs with an altitude difference of 120 m
and cover the period September 2001 to September 2006. Air temperature
at the AWS locations is found to be highly correlated, even with the
seasonal cycle removed. The most striking difference between the two
sites is the difference in wind climate. Midtdalsbreen is much more
under influence of the large-scale circulation with wind speeds on
average a factor 1.75 higher. On Storbreen, weaker katabatic winds are
dominant. The main melt season is from May to September at both
locations. During the melt season, incoming and net solar radiation
are larger on Midtdalsbreen, whereas incoming and net longwave
radiation are larger on Storbreen, primarily caused by thicker clouds
on the latter. The turbulent fluxes are a factor 1.7 larger on
Midtdalsbreen, mainly due to the higher wind speeds. Inter-daily
fluctuations in the surface energy fluxes are very similar at the AWS
sites. On average, melt energy is a factor 1.3 larger on
Midtdalsbreen, a result of both larger net radiation and larger
turbulent fluxes. The relative contribution of net radiation to
surface melt is larger on Storbreen (76%) than on Midtdalsbreen
(66%). As winter snow depth at the two locations is comparable in
most years, the larger amount of melt energy results in an earlier
disappearance of the snowpack on Midtdalsbreen and 70% more ice
melt than on Storbreen. We compare the relative and absolute values of
the energy fluxes on Storbreen and Midtdalsbreen with reported values
for glaciers at similar latitudes. Furthermore, a comparison is made
with meteorological variables measured at two nearby weather stations,
showing that on-site measurements are essential for an accurate
calculation of the surface energy balance and melt rate. |
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