How robust are in situ observations for validating satellite-derived albedo over the dark zone of the Greenland Ice Sheet?
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10370086" target="_blank" >RIV/00216208:11310/17:10370086 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1002/2017GL073661" target="_blank" >http://dx.doi.org/10.1002/2017GL073661</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1002/2017GL073661" target="_blank" >10.1002/2017GL073661</a>
Alternative languages
Result language
angličtina
Original language name
How robust are in situ observations for validating satellite-derived albedo over the dark zone of the Greenland Ice Sheet?
Original language description
Calibration and validation of satellite-derived ice sheet albedo data require high-quality, in situ measurements commonly acquired by up and down facing pyranometers mounted on automated weather stations (AWS). However, direct comparison between ground and satellite-derived albedo can only be justified when the measured surface is homogeneous at the length-scale of both satellite pixel and in situ footprint. Here we use digital imagery acquired by an unmanned aerial vehicle to evaluate point-to-pixel albedo comparisons across the western, ablating margin of the Greenland Ice Sheet. Our results reveal that in situ measurements overestimate albedo by up to 0.10 at the end of the melt season because the ground footprints of AWS-mounted pyranometers are insufficient to capture the spatial heterogeneity of the ice surface as it progressively ablates and darkens. Statistical analysis of 21 AWS across the entire Greenland Ice Sheet reveals that almost half suffer from this bias, including some AWS located within the wet snow zone.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10508 - Physical geography
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Geophysical Research Letters
ISSN
0094-8276
e-ISSN
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Volume of the periodical
44
Issue of the periodical within the volume
12
Country of publishing house
US - UNITED STATES
Number of pages
8
Pages from-to
6218-6225
UT code for WoS article
000405854200040
EID of the result in the Scopus database
2-s2.0-85021300223