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Titel |
Satellite observations of changes in snow-covered land surface albedo during spring in the Northern Hemisphere |
VerfasserIn |
K. Atlaskina, F. Berninger, G. Leeuw |
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. 5 ; Nr. 9, no. 5 (2015-09-24), S.1879-1893 |
Datensatznummer |
250116854
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Publikation (Nr.) |
copernicus.org/tc-9-1879-2015.pdf |
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Zusammenfassung |
Thirteen years of Moderate Resolution Imaging Spectroradiometer (MODIS) surface albedo data for the Northern Hemisphere
during the spring months (March–May) were analyzed to determine temporal and
spatial changes over snow-covered land surfaces. Tendencies in land surface
albedo change north of 50° N were analyzed using data on snow
cover fraction, air temperature, vegetation index and precipitation. To this
end, the study domain was divided into six smaller areas, based on their
geographical position and climate similarity. Strong differences were
observed between these areas. As expected, snow cover fraction (SCF) has a
strong influence on the albedo in the study area and can explain 56 % of
variation of albedo in March, 76 % in April and 92 % in May. Therefore
the effects of other parameters were investigated only for areas with
100 % SCF. The second largest driver for snow-covered land surface albedo
changes is the air temperature when it exceeds a value between
−15 and −10 °C, depending on the region. At monthly
mean air temperatures below this value no albedo changes are observed.
The Enhanced Vegetation Index (EVI) and precipitation amount and frequency were
independently examined as possible candidates to explain observed changes in
albedo for areas with 100 % SCF. Amount and frequency of precipitation
were identified to influence the albedo over some areas in Eurasia and North
America, but no clear effects were observed in other areas. EVI is
positively correlated with albedo in Chukotka Peninsula and negatively in
eastern Siberia. For other regions the spatial variability of the
correlation fields is too high to reach any conclusions. |
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