{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T18:48:21Z","timestamp":1780339701313,"version":"3.54.1"},"reference-count":65,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,2,20]],"date-time":"2020-02-20T00:00:00Z","timestamp":1582156800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Quaternary Research Center","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}]},{"name":"Bear Fight Institute","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}]},{"name":"College of the Environment, University of Washington","award":["N\/A"],"award-info":[{"award-number":["N\/A"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Permafrost is degrading under current warming conditions, disrupting infrastructure, releasing carbon from soils, and altering seasonal water availability. Therefore, it is important to quantitatively map the change in the extent and depth of permafrost. We used satellite images of land-surface temperature to recognize and map the zero curtain, i.e., the isothermal period of ground temperature during seasonal freeze and thaw, as a precursor for delineating permafrost boundaries from remotely sensed thermal-infrared data. The phase transition of moisture in the ground allows the zero curtain to occur when near-surface soil moisture thaws or freezes, and also when ice-rich permafrost thaws or freezes. We propose that mapping the zero curtain is a precursor to mapping permafrost at shallow depths. We used ASTER and a MODIS-Aqua daily afternoon land-surface temperature (LST) timeseries to recognize the zero curtain at the 1-km scale as a \u201cproof of concept.\u201d Our regional mapping of the zero curtain over an area around the 7000 m high volcano Ojos del Salado in Chile suggests that the zero curtain can be mapped over arid regions of the world. It also indicates that surface heterogeneity, snow cover, and cloud cover can hinder the effectiveness of our approach. To be of practical use in many areas, it may be helpful to reduce the topographic and compositional heterogeneity in order to increase the LST accuracy. The necessary finer spatial resolution to reduce these problems is provided by ASTER (90 m).<\/jats:p>","DOI":"10.3390\/rs12040695","type":"journal-article","created":{"date-parts":[[2020,2,21]],"date-time":"2020-02-21T08:59:47Z","timestamp":1582275587000},"page":"695","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Toward the Detection of Permafrost Using Land-Surface Temperature Mapping"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7806-8361","authenticated-orcid":false,"given":"Jigjidsurengiin","family":"Batbaatar","sequence":"first","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alan R.","family":"Gillespie","sequence":"additional","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ronald S.","family":"Sletten","sequence":"additional","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amit","family":"Mushkin","sequence":"additional","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"},{"name":"Geological Survey of Israel, 32 Yishayahu Leibovitz St., Jerusalem 9692100, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rivka","family":"Amit","sequence":"additional","affiliation":[{"name":"Geological Survey of Israel, 32 Yishayahu Leibovitz St., Jerusalem 9692100, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dar\u00edo","family":"Trombotto Liaudat","sequence":"additional","affiliation":[{"name":"Geocryology, Instituto Argentino de Nivolog\u00eda, Glaciolog\u00eda y Ciencias Ambientales (IANIGLA), CCT CONICET Mendoza, Bajada del Cerro s\/n, P.O. Box 330, Mendoza 5500, Argentina"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6101-7215","authenticated-orcid":false,"given":"Lu","family":"Liu","sequence":"additional","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregg","family":"Petrie","sequence":"additional","affiliation":[{"name":"University of Washington, Department of Earth and Space Science and Quaternary Research Center, Box 351310, Seattle, WA 98195-1310, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1038\/nature14338","article-title":"Climate change and the permafrost carbon feedback","volume":"520","author":"Schuur","year":"2015","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1038\/s41467-018-08240-4","article-title":"Permafrost is warming at a global scale","volume":"10","author":"Biskaborn","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"French, H.M. (2007). The Periglacial Environment, John Wiley & Sons. [3rd ed.].","DOI":"10.1002\/9781118684931"},{"key":"ref_4","unstructured":"Smith, S., and Brown, J. (2009). Assessment of the Status of the Development of Standards for the Terrestrial Essential Climate Variables\u2014T7\u2014Permafrost and Seasonally Frozen Ground."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/j.earscirev.2019.04.023","article-title":"Northern Hemisphere permafrost map based on TTOP modelling for 2000\u20132016 at 1 km2 scale","volume":"193","author":"Obu","year":"2019","journal-title":"Earth-Sci. Rev."},{"key":"ref_6","first-page":"103037","article-title":"Northern Hemisphere permafrost extent: Drylands, glaciers and sea floor. Comment to the paper: Obu, J.; et al. 2019. Northern Hemisphere permafrost map based on TTOP modeling for 2000\u20132016 at 1 km2 scale","volume":"193","year":"2019","journal-title":"Earth-Sci. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1038\/d41586-019-01313-4","article-title":"Permafrost collapse is accelerating carbon release","volume":"569","author":"Turetsky","year":"2019","journal-title":"Nature"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"He, H., and Dyck, M. (2013). Application of Multiphase Dielectric Mixing Models for Understanding the Effective Dielectric Permitivity of Frozen Soils. Vadose Zone J., 12.","DOI":"10.2136\/vzj2012.0060"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e2019RG000652","DOI":"10.1029\/2019RG000652","article-title":"Space-Based Observations for Understanding Changes in the Arctic-Boreal Zone","volume":"58","author":"Duncan","year":"2020","journal-title":"Rev. Geophys."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Du, J., Watts, J.D., Jiang, L., Lu, H., Cheng, X., Duguay, C., Farina, M., Qiu, Y., Kim, Y., and Kimball, J.S. (2019). Remote Sensing of Environmental Changes in Cold Regions: Methods, Achievements and Challenges. Remote Sens., 11.","DOI":"10.3390\/rs11161952"},{"key":"ref_11","first-page":"1509","article-title":"The zero-curtain effect: Heat and mass transfer across an isothermal region in freezing soil","volume":"26","author":"Outcalt","year":"1990","journal-title":"Water Resour. Res."},{"key":"ref_12","unstructured":"Kane, D.L., and Hinkel, K.M. (2008). What dictates the occurrence of zero curtain effect?. Ninth International Conference on Permafrost, Institute of Northern Engineering, University of Alaska Fairbanks."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"145","DOI":"10.5194\/tc-12-145-2018","article-title":"Mapping permafrost landscape features using object-based image classification of multi-temporal SAR images","volume":"12","author":"Yi","year":"2018","journal-title":"Cryosphere"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"721","DOI":"10.5194\/se-5-721-2014","article-title":"Thermal characterization of the active layer at the Limnopolar Lake CALM-S site on Byers Peninsula (Livingston Island), Antarctica","volume":"5","author":"Ramos","year":"2014","journal-title":"Solid Earth"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S1571-0866(07)10012-9","article-title":"Geocryology of southern South America","volume":"Volume 11","author":"Rabassa","year":"2008","journal-title":"Late Cenozoic of Patagonia and Tierra del Fuego"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1002\/ppp.1989","article-title":"Shallow ground temperature measurements on the highest volcano on Earth, Mt. Ojos del Salado, Arid Andes, Chile","volume":"30","author":"Nagy","year":"2019","journal-title":"Permafr. Periglac."},{"key":"ref_17","first-page":"300","article-title":"Rockslides and rock avalanches in the Central Andes of Argentina and their possible association with permafrost degradation","volume":"30","author":"Baldis","year":"2019","journal-title":"Permafr. Periglac."},{"key":"ref_18","unstructured":"Obu, J., Westermann, S., K\u00e4\u00e4b, A., and Bartsch, A. (2019). Ground Temperature Map, 2000\u20132016, Andes, New Zealand and East African Plateau Permafrost, PANGAEA."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1002\/ppp.614","article-title":"Recent Contributions to the Study of Past Permafrost","volume":"19","author":"French","year":"2008","journal-title":"Permafr. Periglac."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5423","DOI":"10.1038\/s41467-018-07663-3","article-title":"Remote sensing quantifies widespread abundance of permafrost region disturbances across the Arctic and Subarctic","volume":"9","author":"Nitze","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1016\/j.rse.2017.10.016","article-title":"Information theoretic evaluation of satellite soil moisture retrievals","volume":"204","author":"Kumar","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2336","DOI":"10.1002\/2017GL072560","article-title":"Potential of satellite-based land emissivity estimates for the detection of high-latitude freeze and thaw states","volume":"44","author":"Prakash","year":"2017","journal-title":"Geophys. Res. Lett."},{"key":"ref_23","unstructured":"Kim, Y., Kimball, J., Glassy, J., and McDonald, K. (2018). MEaSUREs Northern Hemisphere Polar EASE-Grid 2.0 Daily 6 km Land Freeze\/Thaw Status from AMSR-E and AMSR2, Version 1, National Snow and Ice Data Center."},{"key":"ref_24","first-page":"F01005","article-title":"Estimating 1992\u20132000 average active layer thickness on the Alaskan North Slope from remotely sensed surface subsidence","volume":"117","author":"Liu","year":"2012","journal-title":"J. Geophys. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.isprsjprs.2018.03.026","article-title":"Mapping permafrost landscape features using object-based image classification of multi-temporal SAR images","volume":"141","author":"Wang","year":"2018","journal-title":"ISPRS J. Photogramm."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"6037","DOI":"10.1109\/TGRS.2019.2903935","article-title":"Retrieval of permafrost active layer properties using time-series P-band radar observations","volume":"57","author":"Chen","year":"2019","journal-title":"IEEE T. Geosci. Remote"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"523","DOI":"10.5194\/gmd-9-523-2016","article-title":"Simulating the thermal regime and thaw processes of ice-rich permafrost ground with the land-surface model CryoGrid 3","volume":"9","author":"Westermann","year":"2016","journal-title":"Geosci. Model Dev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4889","DOI":"10.1029\/2018GL078007","article-title":"Statistical Forecasting of Current and Future Circum-Arctic Ground Temperatures and Active Layer Thickness","volume":"45","author":"Aalto","year":"2018","journal-title":"Geophys. Res. Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2087","DOI":"10.5194\/tc-13-2087-2019","article-title":"Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis","volume":"13","author":"Tao","year":"2019","journal-title":"Cryosphere"},{"key":"ref_30","unstructured":"Wan, Z., Hook, S., and Hulley, G. (2018, April 15). MOD11A1 MODIS\/Terra Land Surface Temperature\/Emissivity Daily L3 Global 1km SIN Grid V006, Distributed by NASA EOSDIS Land Processes DAAC. Available online: https:\/\/doi.org\/10.5067\/MODIS\/MOD11A1.006."},{"key":"ref_31","unstructured":"Wan, Z., Hook, S., and Hulley, G. (2018, April 15). MYD11A1 MODIS\/Aqua Land Surface Temperature\/Emissivity Daily L3 Global 1km SIN Grid V006, Distributed by NASA EOSDIS Land Processes DAAC. Available online: https:\/\/doi.org\/10.5067\/MODIS\/MYD11A1.006."},{"key":"ref_32","unstructured":"Brown, O.B., and Minnett, P.J. (1994). MODIS Infrared Sea Surface Temperature Algorithm, University of Florida. Algorithm Theoretical Basis Document, NASA Contract Number NAS5-31361."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"D23113","DOI":"10.1029\/2012JD018506","article-title":"Quantifying uncertainties in land surface temperature (LST) and emissivity retrievals from ASTER and MODIS thermal infrared data","volume":"117","author":"Hulley","year":"2012","journal-title":"J. Geophys. Res."},{"key":"ref_34","unstructured":"NASA\/METI\/AIST\/Japan Spacesystems, and U.S.\/Japan ASTER Science Team (2019, October 01). ASTER Level 2 Surface Temperature Product, ASTER Kinetic Surface Temperature (AST_08), and Registered Radiance (AST_L1B version 3) Images from April 8, 2017 (Granule UR AST_L1B.003:2248631617), NASA EOSDIS Land Processes DAAC at the USGS Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota, Available online: https:\/\/doi.org\/10.5067\/ASTER\/AST_08.003."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"D01103","DOI":"10.1029\/2007JD008470","article-title":"A global monthly land surface air temperature analysis for 1948\u2013present","volume":"113","author":"Fan","year":"2008","journal-title":"J. Geophys. Res."},{"key":"ref_36","unstructured":"NASA JPL (2019, October 01). NASA Shuttle Radar Topography Mission Global 1 arc Second, Distributed by NASA EOSDIS Land Processes DAAC at the USGS Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota, Available online: https:\/\/doi.org\/10.5067\/MEaSUREs\/SRTM\/SRTMGL1N.003."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1175\/1520-0477(1996)077<0437:TNYRP>2.0.CO;2","article-title":"The NCEP\/NCAR 40-year re-analysis project","volume":"77","author":"Kalnay","year":"1995","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.gloplacha.2018.02.006","article-title":"Sensitivity of glaciation in the arid subtropical Andes to changes in temperature, precipitation, and solar radiation","volume":"163","author":"Vargo","year":"2018","journal-title":"Glob. Planet. Chang."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Trombotto, D.T. (2000). Survey of Cryogenic Processes, Periglacial Forms and Permafrost Conditions in South America, Revista do Instituto Geol\u00f3gico.","DOI":"10.5935\/0100-929X.20000004"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"221","DOI":"10.5194\/tc-6-221-2012","article-title":"Derivation and analysis of a high-resolution estimate of global permafrost zonation","volume":"6","author":"Gruber","year":"2012","journal-title":"Cryosphere"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1144\/gsjgs.144.1.0085","article-title":"Geology and geochemistry of the Ojos del Salado volcanic region, Chile","volume":"144","author":"Baker","year":"1987","journal-title":"J. Geol. Soc."},{"key":"ref_42","unstructured":"Schneider, U., Becker, A., Finger, P., Meyer-Christoffer, A., Rudolf, B., and Ziese, M. (2016, January 10). GPCC Full Data Reanalysis Version 7.0: Monthly Land-surface Precipitation from Rain Gauges Built on GTS Based and Historic Data; Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. Available online: https:\/\/doi.org\/10.5065\/D6000072."},{"key":"ref_43","first-page":"654","article-title":"Cryophenomena in the Cold Desert of Atacama","volume":"Volume 14","author":"Buchroithner","year":"2012","journal-title":"EGU General Assembly Conference Abstracts"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.quaint.2017.04.033","article-title":"An inventory of cryospheric landforms in the arid diagonal of South America (high Central Andes, Atacama region, Chile)","volume":"438","author":"Ulloa","year":"2017","journal-title":"Quatern. Int."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"D04102","DOI":"10.1029\/2008JD010519","article-title":"Regional cooling in a warming world: Recent temperature trends in the southeast Pacific and along the west coast of subtropical South America (1979\u20132006)","volume":"114","author":"Falvey","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_46","unstructured":"Hall, D.K., Riggs, G.A., and Salomonson, V.V. (2006). MODIS\/Terra Snow Cover 5-Min L2 Swath 500m. Version 5."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.rse.2008.11.007","article-title":"The ASTER spectral library version 2.0","volume":"113","author":"Baldridge","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"2753","DOI":"10.1080\/014311698214497","article-title":"Classification-based emissivity for land surface temperature measurement from space","volume":"19","author":"Snyder","year":"1998","journal-title":"Int. J. Remote Sens."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1016\/j.rse.2006.06.026","article-title":"New refinements and validation of the MODIS land-surface temperature\/emissivity products","volume":"112","author":"Wan","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.rse.2013.08.027","article-title":"New refinements and validation of the Collection-6 MODIS land-surface temperature\/emissivity products","volume":"140","author":"Wan","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_51","unstructured":"Ackerman, S.A., and Frey, R. (2019, December 10). MODIS Atmosphere L2 Cloud Mask Product (35_L2). NASA MODIS Adaptive Processing System at the Goddard Space Flight Center, Greenbelt, MD, USA. Available online: http:\/\/dx.doi.org\/10.5067\/MODIS\/MYD35_L2.006."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1080\/0143116031000116417","article-title":"Quality assessment and validation of the MODIS global land surface temperature","volume":"25","author":"Wan","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"20180161","DOI":"10.1098\/rsta.2018.0161","article-title":"Optical properties of ice and snow","volume":"377","author":"Warren","year":"2019","journal-title":"Philos. T. Roy. Soc. A"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"99","DOI":"10.3189\/S0022143000015756","article-title":"Solar-heating rates and temperature profiles in Antarctic snow and ice","volume":"39","author":"Brandt","year":"1993","journal-title":"J. Glaciol."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"24235","DOI":"10.1029\/94JB00579","article-title":"Measurements of thermal infrared spectral reflectance of frost, snow, and ice","volume":"99","author":"Salisbury","year":"1994","journal-title":"J. Geophys. Res."},{"key":"ref_56","first-page":"F02S03","article-title":"Responses of permafrost to climate change and their environmental significance, Qinghai-Tibet Plateau","volume":"112","author":"Cheng","year":"2007","journal-title":"J. Geophys. Res. Earth"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1657\/AAAR00C-13-128","article-title":"Temperature-dependent adjustments of the permafrost thermal profiles on the Qinghai-Tibet Plateau, China","volume":"47","author":"Changwei","year":"2015","journal-title":"Arct. Antarct. Alp. Res."},{"key":"ref_58","first-page":"F04018","article-title":"Quantifying landscape differences across the Tibetan plateau: Implications for topographic relief evolution","volume":"113","author":"Tapponnier","year":"2008","journal-title":"J. Geophys. Res-Earth"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"2207","DOI":"10.1109\/TGRS.2006.872081","article-title":"On the blending of the Landsat and MODIS surface reflectance: Predict daily Landsat surface reflectance","volume":"44","author":"Gao","year":"2006","journal-title":"IEEE Trans. Geosci. Remote. Sens."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"4563","DOI":"10.1002\/2016JD024835","article-title":"Extreme temperature and precipitation events in March 2015 in central and northern Chile","volume":"121","author":"Barrett","year":"2016","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"98","DOI":"10.2136\/sh1989.4.0098","article-title":"Classification of Permafrost Soils","volume":"30","author":"Moore","year":"1989","journal-title":"Soil Horiz."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1002\/2014JF003415","article-title":"An enhanced model of the contemporary and long-term (200 ka) sublimation of the massive subsurface ice in Beacon Valley, Antarctica","volume":"120","author":"Liu","year":"2015","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1797","DOI":"10.1029\/2017JF004535","article-title":"Thermal regime and properties of soils and ice-rich permafrost in Beacon Valley, Antarctica","volume":"123","author":"Liu","year":"2018","journal-title":"J. Geophys. Res. Earth"},{"key":"ref_64","doi-asserted-by":"crossref","unstructured":"Gillespie, A.R., Batbaatar, J., Sletten, R.S., Trombotto, D., O\u2019Neal, M., Hanson, B., and Mushkin, A. (2017). Monitoring and mapping soil ice\/water phase transitions in arid regions. Geological Society of America Abstracts with Programs, Geological Society of America.","DOI":"10.1130\/abs\/2017AM-303402"},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1002\/ppp.688","article-title":"Thermal state of permafrost and active layer in Central Asia during the International Polar Year","volume":"21","author":"Zhao","year":"2010","journal-title":"Permafr. Periglac."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/4\/695\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T08:59:30Z","timestamp":1760173170000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/4\/695"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,20]]},"references-count":65,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,2]]}},"alternative-id":["rs12040695"],"URL":"https:\/\/doi.org\/10.3390\/rs12040695","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,2,20]]}}}