{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:39:56Z","timestamp":1760240396375,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,5,31]],"date-time":"2019-05-31T00:00:00Z","timestamp":1559260800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100012258","name":"Polar Knowledge Canada","doi-asserted-by":"publisher","award":["grant #NST-1718-0024."],"award-info":[{"award-number":["grant #NST-1718-0024."]}],"id":[{"id":"10.13039\/100012258","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The Canadian Arctic Archipelago (CAA) presents unique challenges to the determination of melt onset (MO) using remote sensing data. High spatial resolution data is required to discern melt onset among the islands and narrow waterways of the region. Current passive microwave retrievals use daily averaged 19 GHz and 37 GHz data from the multi-channel microwave radiometer (SMMR) and\/or the special sensor microwave\/imager (SSM\/I). The development of a new passive microwave melt onset method capable of using higher resolution data is desirable. The new passive microwave melt onset method described here, named the Dynamic Threshold Variability Method (DTVM), uses higher resolution data from the 37 GHz vertically-polarized channel from the advanced microwave scanning radiometers (AMSR-E and AMSR-2). The DTVM MO detection methodology differs from previously presented passive microwave Arctic MO methods in that it does not use a fixed threshold of a brightness temperature parameter. Instead, the DTVM determines MO dates based on the distribution of dates corresponding to the exceedance of a range of brightness temperature variability thresholds. The method also uses swath data instead of daily averaged brightness temperatures, which is found to lead to improved melt detection. Two current passive microwave MO methods are compared and evaluated for applicability in the CAA alongside the DTVM. The DTVM provides MO dates at a higher spatial resolution than earlier methods in addition to higher correlation with MO dates from surface air temperature (SAT) reanalyses. It is found that, for some years, MO dates in the CAA exhibit a latitudinal dependence, while in other years the MO dates in the CAA are relatively uniform across the domain.<\/jats:p>","DOI":"10.3390\/rs11111304","type":"journal-article","created":{"date-parts":[[2019,5,31]],"date-time":"2019-05-31T11:59:56Z","timestamp":1559303996000},"page":"1304","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Passive Microwave Melt Onset Retrieval Based on a Variable Threshold: Assessment in the Canadian Arctic Archipelago"],"prefix":"10.3390","volume":"11","author":[{"given":"Stephen","family":"Marshall","sequence":"first","affiliation":[{"name":"Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K. Andrea","family":"Scott","sequence":"additional","affiliation":[{"name":"Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2761-4809","authenticated-orcid":false,"given":"Randall K.","family":"Scharien","sequence":"additional","affiliation":[{"name":"Department of Geography, University of Victoria, Victoria, BC V8P 5C2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3679","DOI":"10.1002\/2013JC009672","article-title":"Surface energy budget of landfast sea ice during the transitions from winter to snowmelt and melt pond onset: The importance of net longwave radiation and cyclone forcings","volume":"119","author":"Else","year":"2014","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1349","DOI":"10.1007\/s00382-011-1196-9","article-title":"Onset and end of the summer melt season over sea ice: Thermal structure and surface energy perspective from SHEBA","volume":"39","author":"Persson","year":"2012","journal-title":"Clim. Dyn."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"355","DOI":"10.3189\/172756411795931714","article-title":"Arctic sea-ice melt in 2008 and the role of solar heating","volume":"52","author":"Perovich","year":"2011","journal-title":"Ann. Glaciol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2499","DOI":"10.1002\/2015JC011588","article-title":"Sea ice melt onset associated with lead opening during the spring\/summer transition near the North Pole","volume":"121","author":"Vivier","year":"2016","journal-title":"J. Geophys. Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"L19505","DOI":"10.1029\/2007GL031480","article-title":"Increasing solar heating of the Arctic Ocean and adjacent seas, 1979\u20132005: Attribution and role in the ice-albedo feedback","volume":"34","author":"Perovich","year":"2007","journal-title":"Geophys. Res. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1002\/2016EF000495","article-title":"Skillful spring forecasts of September Arctic sea ice extent using passive microwave sea ice observations","volume":"5","author":"Petty","year":"2017","journal-title":"Earth\u2019s Future"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"C12024","DOI":"10.1029\/2009JC005436","article-title":"Recent changes in Arctic sea ice melt onset, freezeup, and melt season length","volume":"114","author":"Markus","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2008JC004730","article-title":"Changing sea ice melt parameters in the Canadian Arctic Archipelago: Implications for the future presence of multiyear ice","volume":"113","author":"Howell","year":"2008","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.rse.2016.03.003","article-title":"Detection of melt onset over the northern Canadian Arctic Archipelago sea ice from RADARSAT, 1997\u20132014","volume":"178","author":"Mahmud","year":"2016","journal-title":"Remote. Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.rse.2013.11.004","article-title":"Extending the QuikSCAT record of seasonal melt-freeze transitions over Arctic sea ice using ASCAT","volume":"141","author":"Mortin","year":"2014","journal-title":"Remote. Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"C08004","DOI":"10.1029\/2012JC008001","article-title":"Mapping of seasonal freeze-thaw transitions across the pan-Arctic land and sea ice domains with satellite radar","volume":"117","author":"Mortin","year":"2012","journal-title":"J. Geophys. Res. Ocean."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9063","DOI":"10.1029\/2018JD028676","article-title":"Arctic Sea Ice Melt Onset Timing From Passive Microwave-Based and Surface Air Temperature-Based Methods","volume":"123","author":"Bliss","year":"2018","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"24033","DOI":"10.1029\/2000JD000171","article-title":"An improved method for determining snowmelt onset dates over Arctic sea ice using scanning multichannel microwave radiometer and special sensor microwave\/imager data","volume":"106","author":"Drobot","year":"2001","journal-title":"J. Geophys. Res."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Tedesco, M. (2007). Snowmelt detection over the Greenland ice sheet from SSM\/I brightness temperature daily variations. Geophys. Res. Lett., 34.","DOI":"10.1029\/2006GL028466"},{"key":"ref_15","first-page":"105","article-title":"Microwave remote sensing, sea ice and arctic climate","volume":"8","author":"Barber","year":"2005","journal-title":"Phys. Can."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1109\/TGRS.1987.289815","article-title":"Seasonal and regional variations of active\/passive microwave signatures of sea ice","volume":"GE-25","author":"Livingstone","year":"1987","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"49","DOI":"10.5194\/tc-13-49-2019","article-title":"Version 2 of the EUMETSAT OSI SAF and ESA CCI sea ice concentration climate data records","volume":"13","author":"Lavergne","year":"2019","journal-title":"Cryosphere"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1002\/qj.2527","article-title":"A comparison of the regional Arctic System Reanalysis and the global ERA-Interim Reanalysis for the Arctic","volume":"142","author":"Bromwich","year":"2016","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"C02303","DOI":"10.1029\/2005JC003384","article-title":"Sea ice remote sensing using AMSR-E 89 GHz channels","volume":"113","author":"Spreen","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_20","unstructured":"Paynter, C. (2018, December 20). Oceanetic 908 Drifter Buoy Sensor Description. Available online: https:\/\/wiki.oceannetworks.ca\/download\/attachments\/38076681\/Oceanetic+908+Drifter+Buoy+Sensor+Description.pdf."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Bliss, A.C., Miller, J.A., and Meier, W.N. (2017). Comparison of passive microwave-derived early melt onset records on Arctic sea ice. Remote. Sens., 9.","DOI":"10.3390\/rs9030199"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2089","DOI":"10.5194\/tc-8-2089-2014","article-title":"Snowmelt onset over Arctic sea ice from passive microwave satellite data: 1979\u20132012","volume":"8","author":"Bliss","year":"2014","journal-title":"Cryosphere"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"27753","DOI":"10.1029\/98JC02416","article-title":"Observation of perennial Arctic sea ice melt and freeze-up using passive microwave data","volume":"103","author":"Smith","year":"1998","journal-title":"J. Geophys. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3571","DOI":"10.1002\/hyp.1034","article-title":"Seasonal charcaterization of microwave emissions from snow-covered first-year sea ice","volume":"15","author":"Harouche","year":"2001","journal-title":"Hydrol. Process."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1175\/1520-0442(2000)013<0896:VISATO>2.0.CO;2","article-title":"Variations in surface air temperature observations in the Arctic, 1979-97","volume":"13","author":"Rigor","year":"2000","journal-title":"J. Clim."},{"key":"ref_26","first-page":"522","article-title":"Recent changes in pan-Arctic melt onset from satellite passive microwave measurements","volume":"10","author":"Wang","year":"2013","journal-title":"Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.rse.2004.05.001","article-title":"Estimating the time of melt onset and freeze onset over Arctic sea ice area using active and passive microwave data","volume":"92","author":"Belchansky","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1216","DOI":"10.1002\/2013GL058951","article-title":"Changes in Arctic melt season and implications for sea ice loss","volume":"41","author":"Stroeve","year":"2014","journal-title":"Geophys. Res. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"(2008). Mulit-year sea-ice conditions in the western Canadian Arctic Archipelago region of the Northwest Passage: 1968\u20132008. Atmos. Ocean., 46, 229\u2013242.","DOI":"10.3137\/ao.460203"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6636","DOI":"10.1002\/2016GL069330","article-title":"Melt onset over Arctic sea ice controlled by atmospheric moisture transport","volume":"43","author":"Mortin","year":"2016","journal-title":"Geophys. Res. Lett."},{"key":"ref_31","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_32","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.rse.2007.02.033","article-title":"On detection of the thermophysical state of landfast first-year sea ice using in-situ microwave emission during spring melt","volume":"111","author":"Hwang","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"891","DOI":"10.5194\/tc-8-891-2014","article-title":"The microwave emissivity variability of snow covered first-year sea ice from late winter to early summer: a model study","volume":"8","author":"Willmes","year":"2014","journal-title":"Cryosphere"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/11\/1304\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:55:11Z","timestamp":1760187311000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/11\/1304"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,5,31]]},"references-count":33,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2019,6]]}},"alternative-id":["rs11111304"],"URL":"https:\/\/doi.org\/10.3390\/rs11111304","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2019,5,31]]}}}