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<article language="en">
	<journal>
		<journal_title>The Cryosphere Discussions</journal_title>
		<journal_url>www.the-cryosphere-discuss.net</journal_url>
		<issn>1994-0432</issn>
		<eissn>1994-0440</eissn>
		<volume_number>6</volume_number>
		<issue_number>1</issue_number>
		<publication_year>2012</publication_year>
	</journal>
	<doi>10.5194/tcd-6-37-2012</doi>
	<article_url>http://www.the-cryosphere-discuss.net/6/37/2012/</article_url>
	<abstract_html>http://www.the-cryosphere-discuss.net/6/37/2012/tcd-6-37-2012.html</abstract_html>
	<fulltext_pdf>http://www.the-cryosphere-discuss.net/6/37/2012/tcd-6-37-2012.pdf</fulltext_pdf>
	<start_page>37</start_page>
	<end_page>88</end_page>
	<publication_date>2012-01-03</publication_date>
	<article_title content_type="html">Remote sensing of sea ice: advances during the DAMOCLES project</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>G. Heygster</name>
			<email>heygster@uni-bremen.de</email>
		</author>
		<author numeration="2" affiliations="2">
			<name>V. Alexandrov</name>
		</author>
		<author numeration="3" affiliations="4">
			<name>G. Dybkjær</name>
		</author>
		<author numeration="4" affiliations="3">
			<name>F. Girard-Ardhuin</name>
		</author>
		<author numeration="5" affiliations="1">
			<name>W. von Hoyningen-Huene</name>
		</author>
		<author numeration="6" affiliations="5">
			<name>I. L. Katsev</name>
		</author>
		<author numeration="7" affiliations="1">
			<name>A. Kokhanovsky</name>
		</author>
		<author numeration="8" affiliations="6">
			<name>T. Lavergne</name>
		</author>
		<author numeration="9" affiliations="5">
			<name>A. V. Malinka</name>
		</author>
		<author numeration="10" affiliations="1">
			<name>C. Melsheimer</name>
		</author>
		<author numeration="11" affiliations="4">
			<name>L. Toudal Pedersen</name>
		</author>
		<author numeration="12" affiliations="5">
			<name>A. S. Prikhach</name>
		</author>
		<author numeration="13" affiliations="7">
			<name>R. Saldo</name>
		</author>
		<author numeration="14" affiliations="4">
			<name>R. Tonboe</name>
		</author>
		<author numeration="15" affiliations="1">
			<name>H. Wiebe</name>
		</author>
		<author numeration="16" affiliations="5">
			<name>E. P. Zege</name>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Institute of Environmental Physics, University of Bremen (UB), Germany</affiliation>
		<affiliation numeration="2" content_type="html">Nansen International Environmental and Remote Sensing Centre (NIERSC), St. Petersburg, Russia and Environmental and Remote Sensing Centre, Bergen, Norway</affiliation>
		<affiliation numeration="3" content_type="html">Institut Français de Recherche pour l&apos;Exploitation de la Mer (IFREMER), Plouzané, France</affiliation>
		<affiliation numeration="4" content_type="html">Danish Meteorological Institute (DMI), Denmark</affiliation>
		<affiliation numeration="5" content_type="html">B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus (IP-NASB), Minsk, Belarus</affiliation>
		<affiliation numeration="6" content_type="html">Norwegian Meteorological Institute (met.no), Oslo, Norway</affiliation>
		<affiliation numeration="7" content_type="html">Danish National Space Center (DNSC), Copenhagen, Denmark</affiliation>
	</affiliations>
	<abstract content_type="html">In the Arctic, global warming is particularly pronounced so that we need to
monitor its development continuously. On the other hand, the vast and
hostile conditions make in situ observation difficult, so that available
satellite observations should be exploited in the best possible way to
extract geophysical information. Here, we give a résumé of the sea
ice remote sensing efforts of the EU project DAMOCLES (Developing Arctic
Modeling and Observing Capabilities for Long-term Environmental Studies).
The monthly variation of the microwave emissivity of first-year and
multiyear sea ice has been derived for the frequencies of the microwave
imagers like AMSR-E and sounding frequencies of AMSU, and has been used to
develop an optimal estimation method to retrieve sea ice and atmospheric
parameters simultaneously. A sea ice microwave emissivity model has been
used together with a thermodynamic model to establish relations between the
emisivities at 6 GHz and 50 GHz. At the latter frequency, the emissivity is
needed for assimilation into atmospheric circulation models, but more
difficult to observe directly. A method to determine the effective size of
the snow grains from observations in the visible range (MODIS) is developed
and applied. The bidirectional reflectivity distribution function (BRDF) of
snow, which is an essential input parameter to the retrieval, has been
measured in situ on Svalbard during the DAMOCLES campaign, and a BRDF model
assuming aspherical particles is developed. Sea ice drift and deformation is
derived from satellite observations with the scatterometer ASCAT (62.5 km
grid spacing), with visible AVHRR observations (20 km), with the synthetic
aperture radar sensor ASAR (10 km), and a multi-sensor product (62.5 km)
with improved angular resolution (Continuous Maximum Cross Correlation, CMCC
method) is presented. CMCC is also used to derive the sea ice deformation,
important for formation of sea ice leads (diverging deformation) and
pressure ridges (converging). The indirect determination of sea ice
thickness from altimeter freeboard data requires knowledge of the ice
density and snow load on sea ice. The relation between freeboard and ice
thickness is investigated based on the airborne Sever expeditions conducted
between 1928 and 1993.</abstract>
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</article>

