TC The Cryosphere TC 1994-0424 Copernicus GmbH Göttingen, Germany 10.5194/tc-6-1411-2012 Remote sensing of sea ice: advances during the DAMOCLES project Heygster G. 1 Alexandrov V. 2 Dybkjær G. 4 von Hoyningen-Huene W. 1 Girard-Ardhuin F. 3 Katsev I. L. 5 Kokhanovsky A. 1 Lavergne T. 6 Malinka A. V. 5 Melsheimer C. 1 Toudal Pedersen L. 4 Prikhach A. S. 5 Saldo R. 7 Tonboe R. 4 Wiebe H. 1 Zege E. P. 5 Institute of Environmental Physics, University of Bremen (UB), Germany Nansen International Environmental and Remote Sensing Centre (NIERSC), St. Petersburg, Russia and Nansen Environmental and Remote Sensing Centre, Bergen, Norway Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) , Plouzané, France Danish Meteorological Institute (DMI), Denmark B.I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus (IP-NASB), Minsk, Belarusian Norwegian Meteorological Institute (met.no), Oslo, Norway Danish National Space Center (DNSC), Copenhagen, Denmark 03 12 2012 6 6 1411 1434 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.the-cryosphere.net/6/1411/2012/tc-6-1411-2012.html The full text article is available as a PDF file from http://www.the-cryosphere.net/6/1411/2012/tc-6-1411-2012.pdf

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 European Union's (EU) project DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies). In order to better understand the seasonal variation of the microwave emission of sea ice observed from space, the monthly variations of the microwave emissivity of first-year and multi-year sea ice have been derived for the frequencies of the microwave imagers like AMSR-E (Advanced Microwave Scanning Radiometer on EOS) and sounding frequencies of AMSU (Advanced Microwave Sounding Unit), and have been used to develop an optimal estimation method to retrieve sea ice and atmospheric parameters simultaneously. In addition, a sea ice microwave emissivity model has been used together with a thermodynamic model to establish relations between the emissivities from 6 GHz to 50 GHz. At the latter frequency, the emissivity is needed for assimilation into atmospheric circulation models, but is more difficult to observe directly. The size of the snow grains on top of the sea ice influences both its albedo and the microwave emission. A method to determine the effective size of the snow grains from observations in the visible range (MODIS) is developed and demonstrated in an application on the Ross ice shelf. 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.

 References Alexandrov, V., Sandven, S., Wahlin, J., and Johannessen, O. M.: The relation between sea ice thickness and freeboard in the Arctic, The Cryosphere, 4, 373–380, http://dx.doi.org/10.5194/tc-4-373-2010doi:10.5194/tc-4-373-2010, 2010. Andersen, S., Tonboe, R., Kaleschke, L., and Heygster, G.: Intercomparison of passive microwave sea ice concentration retrievals over the high-concentration Arctic sea ice, J. Geophys. Res., 112, C08004, http://dx.doi.org/10.1029/2006JC003543doi:10.1029/2006JC003543, 2007. Aoki T., Hori, M., Motoyoshi, H., Tanikawa, T., Hachikubo, A., Sugiura, K., Yasunari, T. J., Storvold, R., Eide, H. A., Stamnes, K., Li, W., Nieke, J., Nakajima, Y., and Takahashi, F.: ADEOS-II/GLI snow/ice products – Part 3: Validation results using GLI and MODIS data, Remote Sens. Environ., 111, 274–290, 2007. Buzuev, A. Y., Romanov, I. P., and Fedyakov, V. E.: Variability of snow distribution on the ice in the Arctic Ocean, Meteorology and Hydrology, 9, 76–85, 1979. Christoffersen, L. L.: The influence of wind on sea ice motion in the Baffin Bay, Master thesis in geophysics University of Copenhagen, April 12, 1–119, 2009. Cavalieri, D. J., Gloersen, P., and Cambell, W. J.: Determination of sea ice parameters with the NIMBUS 7 SMMR, J. Geophys. Res. 89, 5355–5369, 1984. Cavalieri, D. J., Markus, T., Ivanoff, A., Miller, J. A., Brucker, L., Sturm, M., Maslanik, J. A., Heinrichs, J. F., Gasiewski, A. J., Leuschen, C., Krabill, W., and Sonntag, J.: A comparison of snow depth on sea ice retrievals using airborne altimeters and an AMSR-E simulator, IEEE T. Geosci. Remote, 50, 3027–3040, http://dx.doi.org/10.1109/TGRS.2011.2180535doi:10.1109/TGRS.2011.2180535, 2012. Comiso, J. C., Cavalieri, D. J., Parkinson, C. L., and Gloersen, P.: Passive microwave algorithms for sea ice concentration: a comparison of two techniques, Remte Sens. Environ., 60, 357–384, 1997. Comiso, J. C., Cavalieri, D. J., and Markus, T.: Sea ice concentration, ice temperature and snow depth using AMSR-E data, IEEE Transactions on Geoscience and Remote Sensing, Divergence, Wolfram Mathworld, 201005, http://mathworld.wolfram.com/Divergence.html, 41, 243–252, http://dx.doi.org/10.1109/TGRS.2002.808307doi:10.1109/TGRS.2002.808307, 2003. Dybkjaer, G.: Velocity and deformation fields from Medium and Low resolve – Passive Microwave and IR AVHRR data, DAMOCLES Deliverable Report D1.2-03d, 1–20, 2010. Eicken, H., Lensu, M., Leppäranta, M., Tucker III, W. B., Gow, A. J., and Salmela, J. O.: Thickness, structure, and properties of level summer multiyear ice in the Eurasian sector of the Arctic Ocean, Geophys. Res., 100, 22697–22710, 1995. Eppler, D. T., Farmer, L. D., Lohanick, A. W,. Andersson, M. R, Cavalieri, D. J., Comiso, J., Gloersen, P., Garrity, C., Grenfell, T. C., Hallikainen, M., Maslanik, J. A., Melloh, R. A., Runbinstein , I., Swift, C. T.: Passive Microwave Signatures of sea ice, in: Microwave Remote Sensing of Sea Ice, edited by: Carsey, F. D., AGU, Washington, DC, Geophys. Monogr. Ser., 68, 462 pp., http://dx.doi.org/10.1029/GM068doi:10.1029/GM068, 1992. Forsstrom, S., Gerland, S., and Pedersen, C. A: Thickness and density of snow-covered sea ice and hydrostatic equilibrium assumption from in situ measurements in Fram Strait, Barents Sea and the Svalbard coast, Ann. Glaciol., 52, 261–270, 2011. Fowler, C., Maslanik, J. , Haran, T., Scambos, T., Key, J., and Emery, W.: AVHRR Polar Pathfinder Twice-daily 5 km EASE-Grid Composites V003, Boulder, Colorado, USA, National Snow and Ice Data Center, Digital media, 2007. Gascard, J. C., Festy, J., le Gogg, H., Weber, M., Bruemmer, B., Offermann, M., Doble, M., Wadhams, P., Forsberg, R., Hanson, S., Skourup, H., Gerland, S., Nicolaus, M., Metaxin, J. P., Grangeon, J., Haapala, J., Rinne, E., Haas, C., Heygster, G., Jakobson, E., Palo, T., Wilkinson, J., Kaleschke, L., Claffey, K., Elder, B., and Bottenheim, J.: Exploring Arctic Transpolar Drift During Dramatic Sea Ice Retreat, EOS Trans., 89, 21–28, 2008. Giles, K. A., Laxon, S. W., and Ridout, A. L.: Circumpolar thinning of Arctic sea ice following the 2007 record ice extent minimum, Geophys. Res. Lett., 35, L22502, http://dx.doi.org/10.1029/2008GL035710doi:10.1029/2008GL035710, 2008. Girard-Ardhuin, F. and Ezraty, R.: Enhanced Arctic sea ice drift estimateion merging radiometer and scatterometer data, IEEE Trans. Geosci. Remote Sens., 50, 2639–2648, http://dx.doi.org/10.1109/TGRS.2012.2184124doi:10.1109/TGRS.2012.2184124, 2012. Gohin, F.: Some active and passive microwave signatures of Antarctic sea ice from mid-winter to spring 1991, Int. J. Remote Sens., 16, 2031–2054, 1995. Haggerty, J. A. and Curry, H. A.: Variability of sea ice emissivity estimated from airborne passive microwave measurements during FIRE SHEBA, J. Geophys. Res., 106, 15265–15277, 2001. Hakkinen, S., Proshutinski, A., and Ashik, I.: Sea ice drift in the Arctic since the 1950's, Geophys. Res. Lett., 35, L19704, http://dx.doi.org/10.1029/2008GL034791doi:10.1029/2008GL034791, 2008. Han W., Stamnes, K., and Lubin, D.: Remote sensing of surface and cloud properties in the Arctic from NOAA AVHRR measurements, J. Appl. Meteor., 38, 989–1012, 1999. Hansen, J. and Nazarenko, L.: Soot climate forcing via snow and ice albedos, Proc. Natl. Acad. Sci., 101, 423–428, http://dx.doi.org/10.1073/pnas.2237157100doi:10.1073/pnas.2237157100, 2004. Heygster, G., Melsheimer, C., Mathew, N., Toudal, L.,. Saldo, R, Andersen, S., Tonboe, R., Schyberg, H., Tveter, F. T., Thyness, V., Gustafsson, N., Landelius, T., Dahlgren, P., and Perov, V.: IOMASA – Integrated Observation and Modeling of the Arctic sea ice and atmosphere, Bull. Am. Met. Soc., 293–297, http://dx.doi.org/10.1175/2008BAMS2202.1doi:10.1175/2008BAMS2202.1, 2009. Hori, M., Aoki, T., Stamnes, K., Chen, B., and Li, W.: Preliminary validation of the GLI cryosphere algorithms with MODIS daytime data, Polar Meteorol. Glaciol., 15, 1–20, 2001. Hwang, B. J. and Barber, D. G.: On the impact of ice emissivity on the sea ice temperature retrieval using passive microwave radiance data, IEEE Geosci. Remote Sens., 6, 448–452, 2008. Hwang, P. and Lavergne, T.: Validation and Comparison of OSI SAF Low and Medium Resolution and IFREMER/Cersat Sea ice drift products, Associated and Visiting Scientist Activity Report, SAF/OSI/CDOP/met.no/SCI/RP/151 – Ocean and Sea Ice Satellite Application Facility, http://osisaf.met.no/docs/OSISAF_IntercomparisonIceDriftProducts_V1p2.pdf, 2010. Kaleschke, L., Maas, N., Haas, C., Hendricks, S., Heygster, G., and Tonboe, R. T.: A sea-ice thickness retrieval model for 1.4 GHz radiometry and application to airborne measurements over low salinity sea-ice, The Cryosphere, 4, 583–592, http://dx.doi.org/10.5194/tc-4-583-2010doi:10.5194/tc-4-583-2010, 2010. Kamachi, M: Advective surface velocities derived from sequential images for rotational flow field: limitations and applications of Maximum Cross Correlation method with rotational registration, J. Geophys. Res., 94, 18227–18233, 1989. Kimura, N.: Sea Ice Motion in Response to Surface Wind and Ocean Current in the Southern Ocean, J. Meteorol. Soc. Jpn., 82, 1223–1231, 2004. Klein, A. G. and Stroeve, J.: Development and validation of a snow albedo algorithm for the MODIS instrument, Ann. Glaciol., 34, 45–52, 2002. Kokhanovsky, A. A. and Breon, F.-M.: Validation of an Analytical Snow BRDF Model Using PARASOL Multi-Angular and Multispectral Observations, IEEE Geosci. Remote Sens. Lett., 9, 928–932, 2012. Kokhanovsky, V., Rozanov, V., Aoki, T., Odermatt, D., Brockmann, C., Krüger, O., Bouvet, M., Drusch, M., and Hori, M.: Sizing snow grains using backscattered solar light, Int. J. Remote Sens., 32, 6975–7008, 2011. Konoshonkin, A. and Borovoi, A.: Glints from cirrus clouds, snow blankets, and sea surfaces, Atti della Accademia Peloritana dei Pericolanti, Supplement 1, 89, C1S8901XXX, 2011. Kurtz, N. T., Markus, T., Cavalieri, D. J., Sparling, L. C., Krabill, W. B., Gasievski, A. J., and Sonntag, J. G.: Estimation of sea ice thickness distributions through the combination of snow depth and satellite laser altimeter data, J. Geophys. Res., 114 C10007, http://dx.doi.org/10.1029/2009JC005292doi:10.1029/2009JC005292, 2009. Kurtz, N. T., Markus, T., Farrell, S. L., Worthern, D. L., and Boisvert, L. N.: Observations of recent Arctic sea ice volume loss and its impact on ocean-atmosphere energy exchange and ice production, J. Geophys. Res., 116 C04015, http://dx.doi.org/10.1029/2010JC006235doi:10.1029/2010JC006235, 2011. Kwok, R.: Contrasts in the sea ice deformation and production in the Arctic seasonal and perennial ice zones, J. Geophys. Res., 111, C11S22, http://dx.doi.org/10.1029/2005JC003246doi:10.1029/2005JC003246, 2006. Kwok, R.: Observational assessment of Arctic Ocean sea ice motion, export, and thickness in CMIP3 climate simulations, J. Geophys. Res., 116, C00D05, http://dx.doi.org/10.1029/2011JC007004doi:10.1029/2011JC007004, 2011. Kwok, R. and Cunningham, G. F.: ICESat over Arctic sea ice: Estimation of snow depth and ice thickness, J. Geophys. Res., 113, C08010, http://dx.doi.org/10.1029/2008JC004753doi:10.1029/2008JC004753, 2008. Kwok, R., Schweiger, A., Rothrock, D. A., Pang, S., and Kottmeier, C.: Sea ice motion from satellite passive microwave imagery assessed with ERS SAR and buoy motions, J. Geophys. Res., 103, 8191–8214, 1998. Kwok, R., Cunningham, G. F., Wensnahan, M., Rigor, I., Zwally, H. J., and Yi, D.: Thinning and volume loss of the Arctic Ocean sea ice cover, 2003–2008, J. Geophys. Res., 114, C07005, http://dx.doi.org/10.1029/2009JC005312doi:10.1029/2009JC005312, 2009. Lavergne, T. and Eastwood, S.: Low resolution sea ice drift Product User's Manual – v1.4. Technical Report SAF/OSI/CDOP/met.no/TEC/MA/128, EUMETSAT\ OSI SAF – Ocean and Sea Ice Satellite Application Facility, 29 pp., 2010. Lavergne, T., Eastwood, S., Teffah, Z., Schyberg, H. and L.-A. Breivik, Sea ice motion from low resolution satellite sensors: an alternative method and its validation in the Arctic. J. Geophys. Res., 115, C10032, http://dx.doi.org/10.1029/2009JC005958doi:10.1029/2009JC005958, 2010. Laxon, S. W., Peacock, N., and Smith, D.: High interannual variability of sea ice thickness in the Arctic region, Nature, 425, 947–949, 2003. Liang, S.: Mapping daily snow/ice shortwave broadband albedo from Moderate Resolution Imaging Spectroradiometer (MODIS): The improved direct retrieval algorithm and validation with Greenland in situ measurements, J. Geophys. Res., 110, D10109, http://dx.doi.org/10.1029/2004JD005493doi:10.1029/2004JD005493, 2005. Loshchilov, V. S.: Snow cover on the ice of the central Arctic. Problemy Arktiki i Antarktiki, 17, 36–45, 1964. Lüpkes, C., Vihma, T., Birnbaum, G., and Wacker, U.: Influence of leads in the sea ice on the temperature of the atmosphere boundary layer during polar night, Geophys. Res. Lett., 35, L03805, http://dx.doi.org/10.1029/2007GL032461doi:10.1029/2007GL032461, 2008. Marcq, S. and Weiss, J.: Influence of sea ice lead-width distribution on turbulent heat transfer between the ocean and the atmosphere, The Cryosphere, 6, 143–156, http://dx.doi.org/10.5194/tc-6-143-2012doi:10.5194/tc-6-143-2012, 2012. Mätzler, C.: Improved Born approximation for scattering of radiation in a granular medium, J. Appl. Phys., 83, 6111–6117, 1998. Mätzler, C. and Wiesmann, A.: Extension of the Microwave Emission Model for Layered Snow-packs to coarse grained snow, Remote Sens. Environ., 70, 317–325, 1999. Mätzler, C., Rosenkranz, P. W., Battaglia, A., and Wigneron, J. P. (Eds.): Thermal Microwave Radiation – Applications for Remote Sensing, IEE Electromagnetic Wave Series, London, UK, 382–400, 2006. Maksimovich, E. and Vihma, T.: The effect of surface heat fluxes on interannualvariability in the spring onset of snow melt in the central Arctic Ocean, J. Geophys. Res., 117, C07012, http://dx.doi.org/10.1029/2011JC007220doi:10.1029/2011JC007220, 2012. Markus, T., Stroeve, J. C., and Miller, J.: Recent changes in Arctic sea ice melt onset, freeze up and melt season length, J. Geophys. Res., 114, C12024, http://dx.doi.org/10.1029/2009JC005436doi:10.1029/2009JC005436, 2009. Maslanik, J., Stroeve J., Fowler, C., and Emory, W.: Distribution and trends in Arctic sea ice age through spring 2011, Geophys. Res. Lett., 38, L13502, http://dx.doi.org/10.1029/2011GL047735doi:10.1029/2011GL047735, 2011. Mathew, N., Heygster, G., Melsheimer, C., and Kaleschke, L.: Surface emissivity of polar regions at AMSU window frequencies, IEEE Trans. Geosci. Remote Sens., 46, 2298–2306, http://dx.doi.org/10.1109/TGRS.2008.916630doi:10.1109/TGRS.2008.916630, 2008. Mathew, N., Heygster, G., and Melsheimer, C.: Surface emissivity of the Arctic sea ice at AMSR-E frequencies, IEEE Trans. Geosci. Remote Sens., 47, 4115–4124, http://dx.doi.org/10.1109/TGRS.2009.2023667doi:10.1109/TGRS.2009.2023667, 2009. Maykut, G. A.: Energy Exchange Over Young Sea Ice in the Central Arctic, J. Geophys. Res., 83, 3646–3658, http://dx.doi.org/10.1029/JC083iC07p03646doi:10.1029/JC083iC07p03646, 1978. Maykut, G. A.: The surface heat and mass balance, in: The geophysics of sea ice, edited by: Untersteiner, N., NATO ASI Series, Plenum Press, New York and London, 395–464, 1986. Melsheimer, C., Heygster, G., Mathew, N., and Toudal Pedersen, L.: Retrieval of Sea Ice Emissivity and Integrated Retrieval of Surface and Atmospheric Parameters over the Arctic from AMSR-E data, J. Remote Sens. Soc. Jpn., 29, 236–241, 2009. Mills, P. and Heygster, G.: Sea ice emissivity modelling at L-band and application to Pol-Ice campaign field data, IEEE Trans. Geosci. Remote Sens., 49, 612–627, 2011. National Snow and Ice data Center, Morphometric characteristics of ice and snow in the Arctic Basin: aircraft landing observations from the Former Soviet Union, 1928–1989, compiled by: Romanov, I. P., Boulder, CO, National Snow and Ice Data Center, Digital media, 2004. Nagawo, M. and Sinha, N. K.: Growth rate and salinity profile of first year sea ice in the Arctic, J. Glaciol. 27, 315–330, 1981. Nazintsev, Y. L.: About snow accumulation on sea ice of the Kara sea, Trudy Arkticheskogo 1 Antarknicheskogo Instituta, 303, 185–191, 1971. Negi, H. S. and Kokhanovsky, A.: Retrieval of snow albedo and grain size using reflectance measurements in Himalayan basin, The Cryosphere, 5, 203–217, http://dx.doi.org/10.5194/tc-5-203-2011doi:10.5194/tc-5-203-2011, 2011. Nicolaus, M. , Gerland, S. , Hudson, S. R. , Hanson, S. , Haapala, J., and Perovich, D. K.: Seasonality of spectral albedo and transmissivity as observed in the Arctic Transpolar Drift in 2007, J. Geophys. Res.-Ocean, 115, C11011, http://dx.doi.org/10.1029/2009JC006074doi:10.1029/2009JC006074, 2010. Ninnis, R. M., Emery, W. J., and Collins, M. J.: Automated extraction of pack ice motion from Advanced Very High Resolution Radiometer imagery, J. Geophys. Res., 91, 10725–10734, 1986. NSIDC: 201104, http://nsidc.org/arcticseaicenews/2011/040511.html, 2012. Pirazzini, R.: Surface albedo measurements over Antarctic sites in summer, J. Geopys. Res., 109, D20118, http://dx.doi.org/10.1029/2004JD004617doi:10.1029/2004JD004617, 2004. Rampal, P., Weiss, J., Marsan, D., Lindsay, R., and Stern, H.: Scaling properties of sea ice deformation from buoy dispersion analysis, J. Geophys. Res., 113, C03002, http://dx.doi.org/10.1029/2007JC004143doi:10.1029/2007JC004143, 2008. Rampal, P., Weiss, J., and Marsan, D.: Positive trend in the mean speed and deformation rate of Arctic sea ice, 1979–2007, J. Geophys. Res., 114, C05013, http://dx.doi.org/10.1029/2008JC005066doi:10.1029/2008JC005066, 2009. Rampal, P., Weiss, J., Dubois, C., and Campin, J.-M.: IPCC climate models do not capture Arctic sea ice drift acceleration: 2 Consequences in terms of projected sea ice thinning and decline, J. Geophys. Res., 116, C00D07, http://dx.doi.org/10.1029/2011JC007110doi:10.1029/2011JC007110, 2011. Riihelä, A., Laine, V., Manninen, T., Palo, T., and Vihma, T.: Validation of the Climate-SAF surface broadband albedo product: comparisons with in situ observations over Greenland and the ice-covered Arctic Ocean, Remote Sensing of Environment, 114, 2779–2790, 2010. Rodgers, C. D.: Inverse Methods for Atmospheric Sounding – Theory and Practise, Vol. 2 of Series on Atmospheric, Oceanic and Planetary Physics, World Scientific, ISBN 981-02-2740-X, 238 pp., 2000. Romanov, I. P.: Atlas of ice and snow of the Arctic Basin and Siberian Shelf seas, Backbone Publishing Company, 496 pp., 1995. Rothrock, D. A., Percival, D. B., and Wensnahan, M.: The decline in arctic sea-ice thickness: Separating the spatial, annual, and interannual variability in a quarter century of submarine data, J. Geophys. Res., 113, C05003, http://dx.doi.org/10.1029/2007JC004252doi:10.1029/2007JC004252, 2008. Rozman, P., Hölemann, J., Krumpen, T., Gerdes, R., Köberle, C., Lavergne, T., Adams, S., and Girard-Ardhuin, F.: Validating satellite derived and modeled sea ice drift in the Laptev sea with In Situ measurements of winter 2007/08, Polar Res., 30, http://dx.doi.org/10.3402/polar.v30i0.7218doi:10.3402/polar.v30i0.7218, 2011. Schwerdtfeger, P.: The thermal properties of sea ice, J. Glaciol., 4, 789–907, 1963. Schyberg, H. and Tveter, F. T.: Report on microwave ice surface emission modelling using NWP model data, DAMOCLES deliverable report D1.2-02.f, 3, 11 pp., 2009. Schyberg, H. and Tveter, F. T.: Improved assimilation method in NWP and impact on forecast quality in the Arctic, DAMOCLES deliverable report D4.3-09, 2010. Seidel, K. and Martinec, J.: Remote Sensing in Snow Hydrology: Runoff Modelling, Effect of Climate Change, Chichester, Springer-Praxis, 150 pp., 2004. Serreze, M. C., Barrett, A. P., Stroeve, J. C., Kindig, D. N., and Holland, M. M.: The emergence of surface-based Arctic amplification, The Cryosphere, 3, 11–19, http://dx.doi.org/10.5194/tc-3-11-2009doi:10.5194/tc-3-11-2009, 2009. Smedsrud, L. H., Sirevaag, A., Kloster, K., Sorteberg, A., and Sandven, S.: Recent wind driven high sea ice area export in the Fram Strait contributes to Arctic sea ice decline, The Cryosphere, 5, 821–829, http://dx.doi.org/10.5194/tc-5-821-2011doi:10.5194/tc-5-821-2011, 2011. Spreen, G., Kaleschke, L., and Heygster, G.: Sea ice remote sensing using AMSR-E 89 GHz channels, J. Geophys. Res., 113, C02S03, http://dx.doi.org/10.1029/2005JC003384doi:10.1029/2005JC003384, 2008. Spreen, G., Kwok, R., and Menemenlis, D.: Trends in Arctic sea ice drift and role of wind forcing, 1992–2009, Geophys. Res. Lett., 38, L19501, http://dx.doi.org/10.1029/2011GL048970doi:10.1029/2011GL048970, 2011. Stamnes, K., Li, W., Eide, H., Aoki, T., Hori, M., and Storvold, R.: ADEOS-II/GLI Snow/Ice Products – Part 1: Scientific Basis, Remote Sensing of the Cryosphere, Special Issue 111, 2–3, 2007. Stern, H. L., and Lindsay, R. W.: Spatial scaling of Arctic sea ice deformation, J. Geophys. Res., 114, C10017, http://dx.doi.org/10.1029/2009JC005380doi:10.1029/2009JC005380, 2009. Stroeve, J., Box, J., Fowler, C., Haran, T., and Key, J.: Intercomparison between in situ and AVHRR Polar Pathfinder-derived Surface Albedo over Greenland, Remte Sens. Environ., 75, 360–374, 2001. Sturm, M., Holmgren, J., and Perovich, D. K. : Winter snow cover on the sea ice of the Arctic Ocean (SHEBA): Temporal evolution and spatial variability, J. Geophys. Res., 107, 8047, http://dx.doi.org/10.1029/2000JC000400doi:10.1029/2000JC000400, 2002. Thorndyke, A. S. and Colony, R.: Sea ice motion in response to geostrophic winds, J. Gephys. Res., 87, 5845–5852, 1982. Timco, G. W., and Frederking, R. M. W.: A review of sea ice density, Cold Reg. Sci. Technol., 24, 1–6, 1996. Tonboe, R.: The simulated sea ice thermal microwave emission at window and sounding frequencies, Tellus, 62, 333–344, http://dx.doi.org/10.1111/j.1600-0870.2010.00434.xdoi:10.1111/j.1600-0870.2010.00434.x, 2010. Tonboe, R. T. and Schyberg, H.: Algorithm theoretical basis document for the OSI SAF 50 GHz sea ice emissivity model. OSI-404, EUMETSAT OSI SAF report, 22, 28 pp., 2011. Tonboe, R., Andersen, S., Toudal, L. and Heygster, G.: Sea ice emission modelling, in: Thermal Microwave Radiation – Applications for Remote Sensing, edited by: Mätzler, C., Rosenkranz, P. W., Battaglia, A., and Wigneron, J. P., IET Electromagnetic Waves Series 52, London, UK, 382–400, 2006. Tonboe, R. T., Dybkjær, G., and Høyer, J. L.: Simulations of the snow covered sea ice surface temperature and microwave effective temperature, Tellus A, 63, 1028–1037, 2011. Tynes, H., Kattawar, G. W., Zege, E. P., Katsev, I. L., Prikhach, A. S., and Chaikovskaya, L. I.: Monte Carlo and multi-component approximation methods for vector radiative transfer by use of effective Mueller matrix calculations, Appl. Opt., 40, 400–412, 2001. Ulaby, F. T., Moore, R. K., and Fung, A. K.: Microwave remote sensing, Active an passive, From Theory to Applications, Artech House, Norwood, MA, USA, 3, 2162 pp., 1986. Vinje, T. and Finnekåasa, Ø.: The ice transport through the Fram Strait, Skrifter Nr. 186, Norsk Polarinstitutt, 39 pp., 1986. Vihma, T., Tisler, P., and Uotila, P.: Atmospheric forcing on the drift of Arctic sea ice in 1989–2009, Geophys. Res. Lett., 39, L02501, http://dx.doi.org/10.1029/2011GL050118doi:10.1029/2011GL050118, 2012. Wadhams, P.: Ice in the Ocean, Gordon and Breach Science Publishers, Amsterdam, 351 pp., 2000. Warren, S. G., Rigor, I. G., Untersteiner, N., Radionov, V. F., Bryazgin, N. N., Aleksandrov, Y. I., and Colony, R.: Snow depth on Arctic Sea Ice, J. Climate, 12, 1814–1829, 1999. Weeks, W. F.: Sea ice properties and geometry, AIDJEX Bulletin 34, 137–172, 1976. Wentz, F. J.: Model function for ocean microwave brightness temperatures, J. Geophys. Res., 88, 1892-1908, 1983. Wentz, F. J. and Meissner, T.: AMSR Ocean Algorithm, Algorithm Theoretical Basis Document (ATBD), Version 2, Remote Sensing Systems, California, US, 55 pp., 2000. Wiebe, H., Heygster, G., Zege, E., Aoki, T., and Hori, M.: Snow grain size retrieval SGSP from optical satellite data: Validation with ground measurements and detection of snowfall events, Remote Sens. Environ., 128, 11–20, 2012. Wiesmann, A. and Mätzler, C.: Microwave emission model of layered snowpacks, Remote Sens. Environ., 70, 307–316, 1999. Wingham, D. J., Francis, C. R., Baker, S., Bouzinac, C., Brockley, D., Cullen, R., de Chateau-Thierry, P., Laxon, S. W., Mallow, U., Mavrocordatos, C., Phalippou, L., Ratier, G., Rey, L., Rostan, F., Viau, P., and Wallis, D. W.: CryoSat: A mission to determine the fluctuations in Earth's land and marine ice fields, Advances in Space Research, 37, 841–871, http://dx.doi.org/10.1016/j.asr.2005.07.027doi:10.1016/j.asr.2005.07.027, 2006. Yakovlev, G. N.: Snow cover on drifting ice in the central Arctic, Problemy Arktiki I Antarktiki, 3, 65–76, 1960. Zege, E. P., Ivanov, A. P., and Katsev, I. L.: Image Transfer through a Scattering Medium, Springer-Verlag, Heidelberg, 139–144, 1991. Zege, E., Katsev, I., Malinka, A., Prikhach, A., and Polonsky, I.: New algorithm to retrieve the effective snow grain size and pollution amount from satellite data, Ann. Glaciol., 49, 139–144, 2008. Zege, E. P., Katsev, I. L., Malinka, A. V., Prikhach, A. S., Heygster, G., and Wiebe, H.: Algorithm of the effective snow grain size and pollution amount retrieval from satellite data, Remote Sens. Environ., 115, 2674–2685, 2011.