{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T03:40:29Z","timestamp":1772595629736,"version":"3.50.1"},"reference-count":51,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2015,11,27]],"date-time":"2015-11-27T00:00:00Z","timestamp":1448582400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Federal Ministry of Education and Research (BMBF)","award":["03G0833D"],"award-info":[{"award-number":["03G0833D"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The North Water (NOW) Polynya is a regularly-forming area of open-water and thin-ice, located between northwestern Greenland and Ellesmere Island (Canada) at the northern tip of Baffin Bay. Due to its large spatial extent, it is of high importance for a variety of physical and biological processes, especially in wintertime. Here, we present a long-term remote sensing study for the winter seasons 1978\/1979 to 2014\/2015. Polynya characteristics are inferred from (1) sea ice concentrations and brightness temperatures from passive microwave satellite sensors (Advanced Microwave Scanning Radiometer (AMSR-E and AMSR2), Scanning Multichannel Microwave Radiometer (SMMR), Special Sensor Microwave Imager\/Sounder (SSM\/I-SSMIS)) and (2) thin-ice thickness distributions, which are calculated using MODIS ice-surface temperatures and European Center for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis data in a 1D thermodynamic energy-balance model. Daily ice production rates are retrieved for each winter season from 2002\/2003 to 2014\/2015, assuming that all heat loss at the ice surface is balanced by ice growth. Two different cloud-cover correction schemes are applied on daily polynya area and ice production values to account for cloud gaps in the MODIS composites. Our results indicate that the NOW polynya experienced significant seasonal changes over the last three decades considering the overall frequency of polynya occurrences, as well as their spatial extent. In the 1980s, there were prolonged periods of a more or less closed ice cover in northern Baffin Bay in winter. This changed towards an average opening on more than 85% of the days between November and March during the last decade. Noticeably, the sea ice cover in the NOW polynya region shows signs of a later-appearing fall freeze-up, starting in the late 1990s. Different methods to obtain daily polynya area using passive microwave AMSR-E\/AMSR2 data and SSM\/I-SSMIS data were applied. A comparison with MODIS data (thin-ice thickness \u2264 20 cm) shows that the wintertime polynya area estimates derived by MODIS are about 30 to 40% higher than those derived using the polynya signature simulation method (PSSM) with AMSR-E data. In turn, the difference in polynya area between PSSM and a sea ice concentration (SIC) threshold of 70% is fairly low (approximately 10%) when applied to AMSR-E data. For the coarse-resolution SSM\/I-SSMIS data, this difference is much larger, particularly in November and December. Instead of a sea ice concentration threshold, the PSSM method should be used for SSM\/I-SSMIS data. Depending on the type of cloud-cover correction, the calculated ice production based on MODIS data reaches an average value of 264.4 \u00b1 65.1 km                                                      3                                  to 275.7 \u00b1 67.4 km                                                      3                                  (2002\/2003 to 2014\/2015) and shows a high interannual variability. Our achieved long-term results underline the major importance of the NOW polynya considering its influence on Arctic ice production and associated atmosphere\/ocean processes.<\/jats:p>","DOI":"10.3390\/rs71215807","type":"journal-article","created":{"date-parts":[[2015,11,27]],"date-time":"2015-11-27T10:25:29Z","timestamp":1448619929000},"page":"15844-15867","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":36,"title":["Multi-Decadal Variability of Polynya Characteristics and Ice Production in the North Water Polynya by Means of Passive Microwave and Thermal Infrared Satellite Imagery"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0134-6890","authenticated-orcid":false,"given":"Andreas","family":"Preu\u00dfer","sequence":"first","affiliation":[{"name":"Department of Environmental Meteorology, Faculty of Regional and Environmental Sciences, University of Trier, Behringstr. 21, 54296 Trier, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4831-9016","authenticated-orcid":false,"given":"G\u00fcnther","family":"Heinemann","sequence":"additional","affiliation":[{"name":"Department of Environmental Meteorology, Faculty of Regional and Environmental Sciences, University of Trier, Behringstr. 21, 54296 Trier, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2710-0699","authenticated-orcid":false,"given":"Sascha","family":"Willmes","sequence":"additional","affiliation":[{"name":"Department of Environmental Meteorology, Faculty of Regional and Environmental Sciences, University of Trier, Behringstr. 21, 54296 Trier, Germany"}]},{"given":"Stephan","family":"Paul","sequence":"additional","affiliation":[{"name":"Department of Environmental Meteorology, Faculty of Regional and Environmental Sciences, University of Trier, Behringstr. 21, 54296 Trier, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2015,11,27]]},"reference":[{"key":"ref_1","unstructured":"Smith, W.O., and Barber, D.G. (2007). Polynyas\u2014Windows to the World, Elsevier Oceanography Series."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9461","DOI":"10.1029\/JC095iC06p09461","article-title":"Polynyas and leads: An overview of physical processes and environment","volume":"95","author":"Smith","year":"1990","journal-title":"J. Geophys. Res."},{"key":"ref_3","first-page":"1","article-title":"Polynya dynamics: A review of observations and modeling","volume":"42","author":"Willmott","year":"2004","journal-title":"Rev. Geophys."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Jakobsson, M., Mayer, L., Coakley, B., Dowdeswell, J.A., Forbes, S., Fridman, B., Hodnesdal, H., Noormets, R., Pedersen, R., and Rebesco, M. (2012). The international bathymetric chart of the Arctic Ocean (IBCAO) version 3.0. Geophys. Res. Lett., 39.","DOI":"10.1029\/2012GL052219"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4893","DOI":"10.1016\/S0967-0645(02)00169-8","article-title":"An overview of physical processes in the North Water","volume":"49","author":"Ingram","year":"2002","journal-title":"Deep-Sea Res. Pt II"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1080\/07055900.2001.9649673","article-title":"Physical processes within the North Water (NOW) polynya","volume":"39","author":"Barber","year":"2001","journal-title":"Atmos. Ocean"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4887","DOI":"10.1016\/S0967-0645(02)00168-6","article-title":"The International North Water Polynya Study (NOW): A brief overview","volume":"49","author":"Deming","year":"2002","journal-title":"Deep-Sea Res. Pt II"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1080\/07055900.2001.9649685","article-title":"Sea-ice and meteorological conditions in Northern Baffin Bay and the North Water polynya between 1979 and 1996","volume":"39","author":"Barber","year":"2001","journal-title":"Atmos. Ocean"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1080\/07055900.2001.9649684","article-title":"On the relationship between spatial patterns of sea-ice type and the mechanisms which create and maintain the North Water (NOW) polynya","volume":"39","author":"Mundy","year":"2001","journal-title":"Atmos. Ocean"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1080\/07055900.2001.9649683","article-title":"Ocean circulation within the North Water polynya of Baffin Bay","volume":"39","author":"Melling","year":"2001","journal-title":"Atmos. Ocean"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"187","DOI":"10.3137\/ao.410301","article-title":"The formation and maintenance of the North Water polynya","volume":"41","author":"Yao","year":"2003","journal-title":"Atmos. Ocean"},{"key":"ref_12","unstructured":"Riggs, G., Hall, D., and Salomonson, V. (2006). MODIS Sea Ice Products User Guide to Collection 5, National Snow and Ice Data Center, University of Colorado."},{"key":"ref_13","unstructured":"Cavalieri, D.J., Markus, T., and Comiso, J.C. (2014). AMSR-E\/Aqua Daily L3 6.25 km 89 GHz Brightness Temperature Polar Grids. Version 3. 2002\u20132011, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_14","unstructured":"Cavalieri, D.J., Markus, T., and Comiso, J.C. (2014). AMSR-E\/Aqua Daily L3 12.5 km Brightness Temperature, Sea Ice Concentration, & Snow Depth Polar Grids. Version 3. 2002\u20132011, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Spreen, G., Kaleschke, L., and Heygster, G. (2008). Sea ice remote sensing using AMSR-E 89 GHz channels. J. Geophys. Res., 113.","DOI":"10.1029\/2005JC003384"},{"key":"ref_16","unstructured":"Cavalieri, D.J., Parkinson, C.L., Gloersen, P., and Zwally, H. (1996). Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM\/I-SSMIS Passive Microwave Data. 1978\u20132014, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_17","unstructured":"Cavalieri, D.J., Gloersen, P., Zwally, H., Maslanik, J., and Stroeve, J. (1999). Near-Real-Time DMSP SSMIS Daily Polar Gridded Brightness Temperatures. 2015, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_18","unstructured":"Maslanik, J., and Stroeve, J. (1999). Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations. 2015, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_19","unstructured":"Maslanik, J., and Stroeve, J. (2004). DMSP SSM\/I-SSMIS Daily Polar Gridded Brightness Temperatures. Version 4. 1992\u20132014, NASA National Snow and Ice Data Center Distributed Active Archive Center."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"C07030","DOI":"10.1029\/2010JC006586","article-title":"Mapping of sea ice production in the Arctic coastal polynyas","volume":"116","author":"Tamura","year":"2011","journal-title":"J. Geophys. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3574","DOI":"10.1002\/2013JC009749","article-title":"Improved mapping of sea ice production in the Arctic Ocean using AMSR-E thin ice thickness algorithm","volume":"119","author":"Iwamoto","year":"2014","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"15803","DOI":"10.1029\/1999JC900081","article-title":"Deriving long-term time series of sea ice cover from satellite passive-microwave multisensor data sets","volume":"104","author":"Cavalieri","year":"1999","journal-title":"J. Geophys. Res. Oceans"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.1109\/TGRS.2004.825587","article-title":"Sea ice surface temperature product from MODIS","volume":"42","author":"Hall","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","unstructured":"Ackerman, S., Frey, R., Strabala, K., Liu, Y., Gumley, L., Baum, B., and Menzel, P. (2010). Discriminating Clear-Sky from Cloud with MODIS Algorithm Theoretical Basis Document (MOD35), Technical Report for MODIS Cloud Mask Team, Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin. Version 6.1."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1002\/qj.828","article-title":"The ERA-Interim reanalysis: Configuration and performance of the data assimilation system","volume":"137","author":"Dee","year":"2011","journal-title":"Q. J. R. Meteor. Soc."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"044002","DOI":"10.1088\/1748-9326\/9\/4\/044002","article-title":"Less winter cloud aids summer 2013 Arctic sea ice return from 2012 minimum","volume":"9","author":"Liu","year":"2014","journal-title":"Environ. Res. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"25753","DOI":"10.1029\/96JC02242","article-title":"Thin ice thickness from satellite thermal imagery","volume":"101","author":"Yu","year":"1996","journal-title":"J. Geophys. Res."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Yu, Y., and Lindsay, R. (2003). Comparison of thin ice thickness distributions derived from RADARSAT Geophysical Processor System and advanced very high resolution radiometer data sets. J. Geophys. Res., 108.","DOI":"10.1029\/2002JC001319"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Drucker, R., Martin, S., and Moritz, R. (2003). Observations of ice thickness and frazil ice in the St. Lawrence Island polynya from satellite imagery, upward looking sonar, and salinity\/temperature moorings. J. Geophys. Res., 108.","DOI":"10.1029\/2001JC001213"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"S196","DOI":"10.5589\/m10-012","article-title":"Cross-validation of polynya monitoring methods from multisensor satellite and airborne data: a case study for the Laptev Sea","volume":"36","author":"Willmes","year":"2010","journal-title":"Can. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3306","DOI":"10.1109\/TGRS.2012.2219539","article-title":"Improvement and sensitivity analysis of thermal thin-ice retrievals","volume":"51","author":"Adams","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.5194\/tc-9-1063-2015","article-title":"Thin-ice dynamics and ice production in the Storfjorden polynya for winter seasons 2002\/2003-2013\/2014 using MODIS thermal infrared imagery","volume":"9","author":"Willmes","year":"2015","journal-title":"Cryosphere"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2027","DOI":"10.5194\/tc-9-2027-2015","article-title":"Long-term coastal-polynya dynamics in the Southern Weddell Sea from MODIS thermal-infrared imagery","volume":"9","author":"Paul","year":"2015","journal-title":"Cryosphere"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1757","DOI":"10.1175\/JTECH2113.1","article-title":"Estimation of thin ice thickness and detection of fast ice from SSM\/I Data in the Antarctic Ocean","volume":"24","author":"Tamura","year":"2007","journal-title":"J. Atmos. Oceanic Technol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"L07606","DOI":"10.1029\/2007GL032903","article-title":"Mapping of sea ice production for Antarctic coastal polynyas","volume":"35","author":"Tamura","year":"2008","journal-title":"Geophys. Res. Lett."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Willmes, S., Adams, S., Schr\u00f6der, D., and Heinemann, G. (2011). Spatio-temporal variability of polynya dynamics and ice production in the Laptev Sea between the winters of 1979\/80 and 2007\/08. Polar Res., 30.","DOI":"10.3402\/polar.v30i0.5971"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Adams, S., Willmes, S., Heinemann, G., Rozman, P., Timmermann, R., and Schr\u00f6der, D. (2011). Evaluation of simulated sea-ice concentrations from sea-ice\/ocean models using satellite data and polynya classification methods. Polar Res., 30.","DOI":"10.3402\/polar.v30i0.7124"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"4473","DOI":"10.1029\/94JC02278","article-title":"A method to estimate subpixel-scale coastal polynyas with satellite passive microwave data","volume":"100","author":"Markus","year":"1995","journal-title":"J. Geophys. Res."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"409","DOI":"10.3189\/172756407782871585","article-title":"Polynya Signature Simulation Method polynya area in comparison to AMSR-E 89 GHz sea-ice concentrations in the Ross Sea and off the Ad\u00e9lie Coast, Antarctica, for 2002\u201305: First results","volume":"46","author":"Kern","year":"2007","journal-title":"Ann. Glaciol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"5042","DOI":"10.3390\/rs70505042","article-title":"Spatial feature reconstruction of cloud-covered areas in daily MODIS composites","volume":"7","author":"Paul","year":"2015","journal-title":"Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"L12706","DOI":"10.1029\/2006GL025723","article-title":"Upper-air temperatures around Greenland: 1964\u20132005","volume":"33","author":"Box","year":"2006","journal-title":"Geophys. Res. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Overland, J.E., Francis, J.A., Hanna, E., and Wang, M. (2012). The recent shift in early summer Arctic atmospheric circulation. Geophys. Res. Lett., 39.","DOI":"10.1029\/2012GL053268"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1002\/wea.660","article-title":"Winter 2009\/2010 temperatures and a record-breaking North Atlantic Oscillation index","volume":"66","author":"Osborn","year":"2011","journal-title":"Weather"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1600","DOI":"10.1002\/2013GL059185","article-title":"Greenland ice sheet melt from MODIS and associated atmospheric variability","volume":"41","author":"Hall","year":"2014","journal-title":"Geophys. res. lett."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Hanna, E., Cropper, T.E., Jones, P.D., Scaife, A.A., and Allan, R. (2014). Recent seasonal asymmetric changes in the NAO (a marked summer decline and increased winter variability) and associated changes in the AO and Greenland Blocking Index. Int. J. Climatol., 35.","DOI":"10.1002\/joc.4157"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"L02502","DOI":"10.1029\/2010GL045662","article-title":"Sea ice response to an extreme negative phase of the Arctic Oscillation during winter 2009\/2010","volume":"38","author":"Stroeve","year":"2011","journal-title":"Geophys. Res. Lett."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"383","DOI":"10.3189\/S0022143000012089","article-title":"Ice conditions of an Arctic polynya: North Water in winter","volume":"32","author":"Steffen","year":"1986","journal-title":"J. Glaciol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4746","DOI":"10.1175\/2007MWR2326.1","article-title":"Low-level jets, orographic effects, and extreme events in Nares Strait: A model-based mesoscale climatology","volume":"136","author":"Samelson","year":"2008","journal-title":"Mon. Wea. Rev."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1631","DOI":"10.1175\/BAMS-83-11-1631","article-title":"NCEP-DOE AMIP-II Reanalysis (R-2)","volume":"83","author":"Kanamitsu","year":"2002","journal-title":"Bull. Amer. Meteor. Soc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2588","DOI":"10.1175\/JCLI-D-13-00014.1","article-title":"Evaluation of seven different atmospheric reanalysis products in the Arctic","volume":"27","author":"Lindsay","year":"2014","journal-title":"J. Climate"},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Kwok, R., Toudal Pedersen, L., Gudmandsen, P., and Pang, S.S. (2010). Large sea ice outflow into the Nares Strait in 2007. Geophys. Res. Lett., 37.","DOI":"10.1029\/2009GL041872"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/12\/15807\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:52:52Z","timestamp":1760215972000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/12\/15807"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,11,27]]},"references-count":51,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2015,12]]}},"alternative-id":["rs71215807"],"URL":"https:\/\/doi.org\/10.3390\/rs71215807","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,11,27]]}}}