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ICESat Observations of Arctic Sea Ice: A First LookAnalysis of near-coincident ICESat and RADARSAT imagery shows that the retrieved elevations from the laser altimeter are sensitive to new openings (containing thin ice or open water) in the sea ice cover as well as to surface relief of old and first-year ice. The precision of the elevation estimates, measured over relatively flat sea ice, is approx. 2 cm. Using the thickness of thin-ice in recent openings to estimate sea level references, we obtain the sea-ice freeboard along the altimeter tracks. This step is necessitated by the large uncertainties in the sea surface topography compared to that required for accurate determination of freeboard. Unknown snow depth introduces the largest uncertainty in the conversion of freeboard to ice thickness. Surface roughness is also derived, for the first time, from the variability of successive elevation estimates along the altimeter track. Overall, these ICESat measurements provide an unprecedented view of the Arctic Ocean ice cover at length scales at and above the spatial dimension of the altimeter footprint of approx. 70 m.
Document ID
20070025099
Document Type
Reprint (Version printed in journal)
Authors
Kwok, Ron (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Zwally, H. Jay (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Yi, Donghui (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 23, 2013
Publication Date
August 18, 2004
Publication Information
Publication: Geophysical Research Letter
Volume: 31
ISSN: 0094-8276
Subject Category
Oceanography
Distribution Limits
Public
Copyright
Other
Keywords
Arctic Ocean
remote sensing
hydrology
snow
ice
global change