{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:51:43Z","timestamp":1760241103965,"version":"build-2065373602"},"reference-count":57,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2019,11,29]],"date-time":"2019-11-29T00:00:00Z","timestamp":1574985600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The variations in the Arctic sea ice thickness (SIT) due to climate change have both positive and negative effects on commercial human activities, the ecosystem, and the Earth\u2019s environment. Satellite microwave remote sensing based on microwave reflection signals reflected by the sea ice surface has been playing an essential role in monitoring and analyzing the Arctic SIT and sea ice concentration (SIC) during the past decades. Recently, passive microwave satellites incorporating an L-band radiometer, such as soil moisture and ocean salinity (SMOS) and soil moisture active passive (SMAP), have been used for analyzing sea ice characteristics, in addition to land and ocean research. In this study, we present a novel method to estimate thin SIT and sea ice roughness (SIR) using a conversion relationship between them, from the SMAP and SMOS data. Methodologically, the SMAP SIR is retrieved. The SMAP thin SIT and SMOS SIR are estimated using a conversion relationship between thin SIT data from SMOS data and SMAP-derived SIR, which is obtained from the spatial and temporal collocation of the SMOS thin SIT and the SIR retrieved from SMAP. Our results for the Arctic sea ice during December for four consecutive years from 2015 to 2018, show high accuracy (bias = \u22122.268 cm, root mean square error (RMSE) = 15.919 cm, and correlation coefficient (CC) = 0.414) between the SMOS-provided thin SIT and SMAP-derived SIT, and good agreement (bias = 0.03 cm, RMSE = 0.228 cm, and CC = 0.496) between the SMOS-estimated SIR and SMAP-retrieved SIR. Consequently, our study could be effectively used for monitoring and analyzing the variation in the Arctic sea ice.<\/jats:p>","DOI":"10.3390\/rs11232835","type":"journal-article","created":{"date-parts":[[2019,11,29]],"date-time":"2019-11-29T10:58:21Z","timestamp":1575025101000},"page":"2835","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Circumpolar Thin Arctic Sea Ice Thickness and Small-Scale Roughness Retrieval Using Soil Moisture and Ocean Salinity and Soil Moisture Active Passive Observations"],"prefix":"10.3390","volume":"11","author":[{"given":"Suna","family":"Jo","sequence":"first","affiliation":[{"name":"Department of Environment, Energy and Geoinfomatics, Sejong University, Seoul 05006, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6831-9291","authenticated-orcid":false,"given":"Hyun-Cheol","family":"Kim","sequence":"additional","affiliation":[{"name":"Korea Polar Research Institute, Incheon 21990, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1293-9405","authenticated-orcid":false,"given":"Young-Joo","family":"Kwon","sequence":"additional","affiliation":[{"name":"Korea Polar Research Institute, Incheon 21990, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5518-9478","authenticated-orcid":false,"given":"Sungwook","family":"Hong","sequence":"additional","affiliation":[{"name":"Department of Environment, Energy and Geoinfomatics, Sejong University, Seoul 05006, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4669","DOI":"10.1175\/2010JCLI3697.1","article-title":"Global trends of sea ice: Small-scale roughness and refractive index","volume":"23","author":"Hong","year":"2010","journal-title":"J. Clim."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1080\/16742834.2008.11446766","article-title":"Decreasing arctic sea ice mirrors increasing CO2 on decadal time scale","volume":"1","author":"Johannessen","year":"2008","journal-title":"Atmos. Ocean. Sci. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"L15501","DOI":"10.1029\/2009GL039035","article-title":"Decline in Arctic sea ice thickness from submarine and ICESat records: 1958\u20132008","volume":"36","author":"Kwok","year":"2009","journal-title":"Geophys. Res. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"732","DOI":"10.1002\/grl.50193","article-title":"CryoSat-2 estimates of Arctic sea ice thickness and volume","volume":"40","author":"Laxon","year":"2013","journal-title":"Geophys. Res. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"L13503","DOI":"10.1029\/2010GL042496","article-title":"Recent loss of floating ice and the consequent sea level contribution","volume":"37","author":"Shepherd","year":"2010","journal-title":"Geophys. Res. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"L16502","DOI":"10.1029\/2012GL052676","article-title":"Trends in Arctic sea ice extent from CMIP5, CMIP3 and observations","volume":"39","author":"Stroeve","year":"2012","journal-title":"Geophys. Res. Lett."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1109\/TGRS.2002.808317","article-title":"Sea ice concentration, ice temperature, and snow depth using AMSR-E data","volume":"41","author":"Comiso","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1080\/2150704X.2014.888106","article-title":"Analysis of sea ice surface properties using ASH and Hong approximations in satellite remote sensing","volume":"5","author":"Hong","year":"2014","journal-title":"Remote Sens. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"866","DOI":"10.1175\/2007JCLI1614.1","article-title":"The influence of cloud and surface properties on the Arctic Ocean shortwave radiation budget in coupled models","volume":"21","author":"Gorodetskaya","year":"2008","journal-title":"J. Clim."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1038\/364215a0","article-title":"Century-scale effects of increased atmospheric CO2 on the ocean-atmosphere system","volume":"364","author":"Manabe","year":"1993","journal-title":"Nature"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s10546-009-9354-x","article-title":"Mesoscale variability in the summer Arctic boundary layer","volume":"130","author":"Mauritsen","year":"2009","journal-title":"Bound. Layer Meteorol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4243","DOI":"10.1175\/JCLI4243.1","article-title":"Influence of Arctic wetlands on Arctic atmospheric circulation","volume":"20","author":"Gutowski","year":"2007","journal-title":"J. Clim."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1175\/2008JAS2840.1","article-title":"Controls on the activation and strength of a high-latitude convective cloud feedback","volume":"66","author":"Abbot","year":"2009","journal-title":"J. Atmos. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1016\/j.rse.2008.12.008","article-title":"The behavior of snow and snow-free surface reflectance in boreal forests: Implications to the performance of snow covered area monitoring","volume":"113","author":"Salminen","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5239","DOI":"10.1175\/JCLI3555.1","article-title":"Surface contribution to planetary albedo variability in cryosphere regions","volume":"18","author":"Qu","year":"2005","journal-title":"J. Clim."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5777","DOI":"10.1175\/2008JCLI2366.1","article-title":"Arctic climate change as manifest in cyclone behavior","volume":"21","author":"Simmonds","year":"2008","journal-title":"J. Clim."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"D15105","DOI":"10.1029\/2011JD015847","article-title":"Dramatic interannual changes of perennial Arctic sea ice linked to abnormal summer storm activity","volume":"116","author":"Screen","year":"2011","journal-title":"J. Geophys. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1007\/s00382-013-1830-9","article-title":"Atmospheric impacts of Arctic sea-ice loss, 1979\u20132009: Separating forced change from atmospheric internal variability","volume":"43","author":"Screen","year":"2014","journal-title":"Clim. Dyn."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s40641-018-0111-4","article-title":"Polar climate change as manifest in atmospheric circulation","volume":"4","author":"Screen","year":"2018","journal-title":"Curr. Clim. Chang. Rep."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/j.rse.2016.05.020","article-title":"2016: New visualizations highlight new information on the contrasting Arctic and Antarctic sea-ice trends since the late 1970s","volume":"183","author":"Parkinson","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_21","unstructured":"Isakov, N.A., Yakovlev, A.N., Nikulin, A.E., Serebryansky, G.Y., and Patrakova, T.A. (1999). The NSR Simulation Study Package 3: Potential Cargo Flow Analysis and Economic Evaluation for the Simulation Study (Russian Part), International Northern Sea Route Programme (INSROP Working Paper 139)."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1002\/2013RG000431","article-title":"Arctic sea ice in transformation: A review of recent observed changes and impacts on biology and human activity","volume":"51","author":"Meier","year":"2014","journal-title":"Rev. Geophys."},{"key":"ref_23","unstructured":"Johannessen, O.M., Alexandrov, V., Sandven, S., Pettersson, L.H., Bobylev, L., and Kloster, L. (2007). Remote sensing of sea ice in the Northern Sea Route\u2014Studies and applications, Springer Praxis Books."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"L22502","DOI":"10.1029\/2008GL035710","article-title":"Circumpolar thinning of Arctic sea ice following the 2007 record ice extent minimum","volume":"35","author":"Giles","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1038\/nature02050","article-title":"High interannual variability of sea ice thickness in the Arctic region","volume":"425","author":"Laxon","year":"2003","journal-title":"Nature"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"L21502","DOI":"10.1029\/2005GL023711","article-title":"Arctic Ocean gravity, geoid and sea ice freeboard heights from ICESat and GRACE","volume":"32","author":"Forsberg","year":"2005","journal-title":"Geophys. Res. Lett."},{"key":"ref_27","first-page":"C07005","article-title":"Thinning and volume loss of the Arctic Ocean sea ice cover: 2003\u20132008","volume":"114","author":"Kwok","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"5355","DOI":"10.1029\/JD089iD04p05355","article-title":"Determination of sea ice parameters with the NIMBUS 7 SMMR","volume":"89","author":"Cavalieri","year":"1984","journal-title":"J. Geophys. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1387","DOI":"10.1109\/36.843033","article-title":"An enhanced NASA team sea ice algorithm","volume":"38","author":"Markus","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"975","DOI":"10.1029\/JC091iC01p00975","article-title":"Characteristics of Arctic winter sea ice from satellite multispectral microwave observations","volume":"91","author":"Comiso","year":"1986","journal-title":"J. Geophys. Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/S0034-4257(01)00333-9","article-title":"Seasonal comparisons of sea ice concentration estimates derived from SSM\/I, OKEAN, and RADARSAT data","volume":"81","author":"Belchansky","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"18329","DOI":"10.1029\/94JC01413","article-title":"Arctic sea ice concentration from special sensor microwave imager and advanced very high resolution radiometer satellite data","volume":"99","author":"Emery","year":"1994","journal-title":"J. Geophys. Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"21971","DOI":"10.1029\/91JC02334","article-title":"NASA team algorithm for sea ice concentration retrieval from Defense Meteorological Satellite Program Special Sensor Microwave Imager: Comparison with Landsat satellite imagery","volume":"96","author":"Steffen","year":"1991","journal-title":"J. Geophys. Res."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3646","DOI":"10.1029\/JC083iC07p03646","article-title":"Energy exchange over young sea-ice in the central Arctic","volume":"83","author":"Maykut","year":"1978","journal-title":"J. Geophys. Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"997","DOI":"10.5194\/tc-8-997-2014","article-title":"SMOS-derived thin sea ice thickness: Algorithm baseline, product specifications and initial verification","volume":"8","author":"Kaleschke","year":"2014","journal-title":"Cryosphere"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"439","DOI":"10.5194\/tc-8-439-2014","article-title":"Empirical sea ice thickness retrieval during the freeze-up period from SMOS high incident angle observations","volume":"8","author":"Huntemann","year":"2014","journal-title":"Cryosphere"},{"key":"ref_37","unstructured":"Heygster, G., Hendricks, S., Kaleschke, L., Maa\u00df, N., Mills, P., Stammer, D., Tonboe, R.T., and Haas, C. (2009). L-Band Radiometry for Sea-Ice Applications, Institute of Environmental Physics, University of Bremen. Final Report for ESA ESTEC Contract 21130\/08\/NL\/EL."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"583","DOI":"10.5194\/tc-4-583-2010","article-title":"A sea-ice thickness retrieval model for 1.4 GHz radiometry and application to airborne measurements over low salinity sea-ice","volume":"4","author":"Kaleschke","year":"2010","journal-title":"Cryosphere"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"L05501","DOI":"10.1029\/2012GL050916","article-title":"Sea ice thickness retrieval from SMOS brightness temperatures during the Arctic freeze-up period","volume":"39","author":"Kaleschke","year":"2012","journal-title":"Geophys. Res. Lett."},{"key":"ref_40","unstructured":"M\u00e4tzler, C. (2001, January 10\u201312). Applications of SMOS over terrestrial ice and snow. Proceedings of the 3rd SMOS Workshop, DLR, Oberpfaffenhofen, Germany."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1007\/BF01030053","article-title":"Physical retrievals of over-ocean rain rate from multichannel microwave imagery. Part I: Theoretical characteristics of normalized polarization and scattering indices","volume":"54","author":"Petty","year":"1994","journal-title":"Meteorol. Atmos. Phys."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3103","DOI":"10.1109\/TGRS.2006.880619","article-title":"Impact of surface roughness on AMSR-E sea ice products","volume":"44","author":"Stroeve","year":"2006","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1391","DOI":"10.1109\/36.763303","article-title":"Rough bare soil reflectivity model","volume":"37","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_44","unstructured":"Ulaby, F.T., Moore, R.K., and Fung, A.E. (1982). Microwave Remote Sensing: Active and Passive Vol. II: Radar Remote Sensing and Surface Scattering and Emission Theory, Addison-Wesley."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1136","DOI":"10.1016\/j.rse.2009.12.015","article-title":"Detection of small-scale roughness and refractive index of sea ice in passive satellite microwave remote sensing","volume":"114","author":"Hong","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1119","DOI":"10.1029\/96JC02991","article-title":"Surface roughness of Baltic sea ice","volume":"102","author":"Manninen","year":"1997","journal-title":"J. Geophys. Res."},{"key":"ref_47","unstructured":"Carlstrom, A. (1991, January 3\u20136). Laser profiler for verification of surface scattering models. Proceedings of the 11th IEEE Geoscience and Remote Sensing Symposium, Espoo, Finland."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/j.rse.2016.03.009","article-title":"SMOS sea ice product: Operational application and validation in the Barents Sea marginal ice zone","volume":"180","author":"Kaleschke","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"5699","DOI":"10.1029\/JC084iC09p05699","article-title":"Effect of surface roughness on the microwave emission from soils","volume":"84","author":"Choudhury","year":"1979","journal-title":"J. Geophys. Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"5917","DOI":"10.1029\/JC077i030p05917","article-title":"A non coherent model for microwave emissions and backscattering from sea surface","volume":"77","author":"Wu","year":"1972","journal-title":"J. Geophys. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2709","DOI":"10.1080\/01431161003627855","article-title":"Surface roughness and polarization ratio in microwave remote sensing","volume":"31","author":"Hong","year":"2010","journal-title":"Int. J. Remote Sens."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"033560","DOI":"10.1117\/1.3265997","article-title":"Retrieval of refractive index over specular surfaces for remote sensing applications","volume":"3","author":"Hong","year":"2009","journal-title":"J. Appl. Remote Sens."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1109\/LGRS.2013.2260524","article-title":"Polarization conversion for specular components of surface reflection","volume":"10","author":"Hong","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_54","unstructured":"Hechts, E. (1998). Optics, Addison Wesley Longman. [3rd ed.]."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"675","DOI":"10.5194\/tc-13-675-2019","article-title":"Combined SMAP\u2013SMOS thin sea ice thickness retrieval","volume":"13","author":"Heygster","year":"2019","journal-title":"Cryosphere"},{"key":"ref_56","doi-asserted-by":"crossref","unstructured":"Williams, T., Korosov, A., Rampal, P., and \u00d3lason, E. (2019). Presentation and evaluation of the Arctic sea ice forecasting system neXtSIM-F. Cryosphere.","DOI":"10.5194\/tc-2019-154"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"18","DOI":"10.3189\/2015AoG69A909","article-title":"Comparing and contrasting the behaviour of Arctic and Antarctic sea ice over the 35-year period 1979\u20132013","volume":"56","author":"Simmonds","year":"2015","journal-title":"Ann. Glaciol."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/23\/2835\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:38:35Z","timestamp":1760189915000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/23\/2835"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,11,29]]},"references-count":57,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2019,12]]}},"alternative-id":["rs11232835"],"URL":"https:\/\/doi.org\/10.3390\/rs11232835","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2019,11,29]]}}}