{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T00:12:29Z","timestamp":1773101549976,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T00:00:00Z","timestamp":1625702400000},"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>Recent observations of rising snow lines and reduced snow-covered areas on glaciers during the October 2020\u2013January 2021 period in the Nepal\u2013China region of Mount Everest in Landsat and Sentinel imagery highlight observations that significant ablation has occurred in recent years on many Himalayan glaciers in the post-monsoon and early winter periods. For the first time, we now have weather stations providing real-time data in the Mount Everest region that may sufficiently transect the post-monsoon snow line elevation region. These sensors have been placed by the Rolex National Geographic Perpetual Planet expedition. Combining in situ weather records and remote sensing data provides a unique opportunity to examine the impact of the warm and dry conditions during the 2020 post-monsoon period through to the 2020\/2021 winter on glaciers in the Mount Everest region. The ablation season extended through January 2021. Winter (DJF) ERA5 reanalysis temperature reconstructions for Everest Base Camp (5315 m) for the 1950\u2013February 2021 period indicate that six days in the January 10\u201315 period in 2021 fell in the top 1% of all winter days since 1950, with January 13, January 14, and January 12, being the first, second, and third warmest winter days in the 72-year period. This has also led to the highest freezing levels in winter for the 1950\u20132021 period, with the January 12\u201314 period being the only period in winter with a freezing level above 6000 m.<\/jats:p>","DOI":"10.3390\/rs13142692","type":"journal-article","created":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T10:42:17Z","timestamp":1625740937000},"page":"2692","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Observations of Winter Ablation on Glaciers in the Mount Everest Region in 2020\u20132021"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9498-9125","authenticated-orcid":false,"given":"Mauri","family":"Pelto","sequence":"first","affiliation":[{"name":"Department of Environmental Science, Nichols College, Dudley, MA 01571, USA"}]},{"given":"Prajjwal","family":"Panday","sequence":"additional","affiliation":[{"name":"Department of Environmental Science, Nichols College, Dudley, MA 01571, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6295-1870","authenticated-orcid":false,"given":"Tom","family":"Matthews","sequence":"additional","affiliation":[{"name":"Department of Geography and Environment, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK"}]},{"given":"Jon","family":"Maurer","sequence":"additional","affiliation":[{"name":"Department of Geography and Planning, Appalachian State University, Boone, NC 28607, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0598-6393","authenticated-orcid":false,"given":"L. Baker","family":"Perry","sequence":"additional","affiliation":[{"name":"Department of Geography and Planning, Appalachian State University, Boone, NC 28607, USA"}]}],"member":"1968","published-online":{"date-parts":[[2021,7,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1016\/j.oneear.2020.10.019","article-title":"Six Decades of Glacier Mass Changes around Mt. Everest Are Revealed by Historical and Contemporary Images","volume":"3","author":"King","year":"2020","journal-title":"One Earth"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"407","DOI":"10.5194\/tc-11-407-2017","article-title":"Spatial variability in mass loss of glaciers in the Everest region, central Himalayas, between 2000 and 2015","volume":"11","author":"King","year":"2017","journal-title":"Cryosphere"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1331","DOI":"10.1029\/2018JF004838","article-title":"Heterogeneous Influence of Glacier Morphology on the Mass Balance Variability in High Mountain Asia","volume":"124","author":"Brun","year":"2019","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1016\/j.oneear.2020.10.011","article-title":"Precipitation Characteristics and Moisture Source Regions on Mt. Everest in the Khumbu, Nepal","volume":"3","author":"Perry","year":"2020","journal-title":"One Earth"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1769","DOI":"10.5194\/tc-7-1769-2013","article-title":"The cryosphere seasonal and annual mass balances of Mera and Pokalde Glaciers (Nepal Himalaya) since 2007","volume":"7","author":"Wagnon","year":"2013","journal-title":"Cryosphere"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1017\/jog.2020.88","article-title":"Reanalysing the 2007\u201319 glaciological mass-balance series of Mera Glacier, Nepal, Central Himalaya, using geodetic mass balance","volume":"67","author":"Wagnon","year":"2021","journal-title":"J. Glaciol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Pelto, M. (2017). Recent Climate Change Impacts on Mountain Glaciers, Available online: https:\/\/www.wiley.com\/en-us\/Recent+Climate+Change+Impacts+on+Mountain+Glaciers-p-9781119068112.","DOI":"10.1002\/9781119068150"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Racoviteanu, A.E., Rittger, K., and Armstrong, R. (2019). An Automated Approach for Estimating Snowline Altitudes in the Karakoram and Eastern Himalaya from Remote Sensing. Front. Earth Sci., 7.","DOI":"10.3389\/feart.2019.00220"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"101718","DOI":"10.1016\/j.isci.2020.101718","article-title":"Into Thick(er) Air? Oxygen Availability at Humans\u2019 Physiological Frontier on Mount Everest","volume":"23","author":"Matthews","year":"2020","journal-title":"iScience"},{"key":"ref_10","unstructured":"European Spatial Agency (ESA) (2015). Sentinel-2 User Handbook, Available online: https:\/\/sentinel.esa.int\/documents\/247904\/685211\/Sentinel-2_User_Handbook."},{"key":"ref_11","unstructured":"(2021, March 18). Landsat 8 OLI\/TIRS Digital Object Identifier, Available online: https:\/\/www.usgs.gov\/centers\/eros\/science\/usgs-eros-archive-landsat-archives-landsat-8-oli-operational-land-imager-and?qt-science_center_objects=0#qt-science_center_objects."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1127","DOI":"10.5194\/tc-5-1127-2011","article-title":"Utility of late summer transient snowline migration rate on Taku Glacier, Alaska","volume":"5","author":"Pelto","year":"2011","journal-title":"Cryosphere"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"649","DOI":"10.3189\/2013JoG12J221","article-title":"Identification of snow ablation rate, ELA, AAR and net mass balance using transient snowline variations on two Arctic glaciers","volume":"59","author":"Mernild","year":"2013","journal-title":"J. Glaciol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3189\/2013AoG62A083","article-title":"Estimating glacier snow accumulation from backward calculation of melt and snowline tracking","volume":"54","author":"Hulth","year":"2013","journal-title":"Ann. Glaciol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1899","DOI":"10.5194\/tc-12-1899-2018","article-title":"Multi-decadal mass balance series of three Kyrgyz glaciers inferred from modelling constrained with repeated snow line observations","volume":"12","author":"Barandun","year":"2018","journal-title":"Cryosphere"},{"key":"ref_16","unstructured":"Zeller, J. (2020). Automated Classification of Supraglacial Surface Facies for Snow Line Altitude Monitoring Using the Google Earth Engine. [Master\u2019s Thesis, University of Zurich]."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"E1870","DOI":"10.1175\/BAMS-D-19-0198.1","article-title":"Going to Extremes: Installing the World\u2019s Highest Weather Stations on Mount Everest","volume":"101","author":"Matthews","year":"2020","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1999","DOI":"10.1002\/qj.3803","article-title":"The ERA5 global reanalysis","volume":"146","author":"Hersbach","year":"2020","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1229","DOI":"10.5194\/tc-9-1229-2015","article-title":"Weak precipitation, warm winters and springs impact glaciers of south slopes of Mt. Everest (central Himalaya) in the last 2 decades (1994\u20132013)","volume":"9","author":"Salerno","year":"2015","journal-title":"Cryosphere"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1105","DOI":"10.5194\/tc-9-1105-2015","article-title":"Modelling glacier change in the Everest region, Nepal Himalaya","volume":"9","author":"Shea","year":"2015","journal-title":"Cryosphere"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41598-019-41657-5","article-title":"Glacier ablation and temperature indexed melt models in the Nepalese Himalaya","volume":"9","author":"Litt","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1017\/jog.2017.30","article-title":"Contrasted surface mass balances of debris-free glaciers observed between the southern and the inner parts of the Everest region (2007\u20132015)","volume":"63","author":"Sherpa","year":"2017","journal-title":"J. Glaciol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Stumm, D., Joshi, S.P., Gurung, T.R., and Silwal, G. (2020). Mass balances of Yala and Rikha Samba Glacier, Nepal from 2000 to 2017. Earth Syst. Sci. Data Discuss.","DOI":"10.5194\/essd-2020-272"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1297","DOI":"10.5194\/tc-8-1297-2014","article-title":"Tracing glacier changes since the 1960s on the south slope of Mt. Everest (central Southern Himalaya) using optical satellite imagery","volume":"8","author":"Thakuri","year":"2014","journal-title":"Cryosphere"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Bocchiola, D., Bombelli, G.M., Camin, F., and Ossi, P.M. (2020). Field Study of Mass Balance, and Hydrology of the West Khangri Nup Glacier (Khumbu, Everest). Water, 12.","DOI":"10.5194\/egusphere-egu2020-17753"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1017\/jog.2019.37","article-title":"Mass balance of Trambau Glacier, Rolwaling region, Nepal Himalaya: In-situ observations, long-term reconstruction and mass-balance sensitivity","volume":"65","author":"Sunako","year":"2019","journal-title":"J. Glaciol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"349","DOI":"10.5194\/tc-5-349-2011","article-title":"Multi-decadal mass loss of glaciers in the Everest area (Nepal Himalaya) derived from stereo imagery","volume":"5","author":"Bolch","year":"2011","journal-title":"Cryosphere"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"648","DOI":"10.3189\/2012JoG11J061","article-title":"Elevation changes of glaciers revealed by multitemporal digital elevation models calibrated by GPS survey in the Khumbu region, Nepal Himalaya, 1992-2008","volume":"58","author":"Nuimura","year":"2012","journal-title":"J. Glaciol."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Bisset, R.R., Dehecq, A., Goldberg, D.N., Huss, M., Bingham, R.G., and Gourmelen, N. (2020). Reversed Surface-Mass-Balance Gradients on Himalayan Debris-Covered Glaciers Inferred from Remote Sensing. Remote. Sens., 12.","DOI":"10.3390\/rs12101563"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"eaav7266","DOI":"10.1126\/sciadv.aav7266","article-title":"Acceleration of ice loss across the Himalayas over the past 40 years","volume":"5","author":"Maurer","year":"2019","journal-title":"Sci. Adv."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41467-021-23073-4","article-title":"Health and sustainability of glaciers in High Mountain Asia","volume":"12","author":"Miles","year":"2021","journal-title":"Nat. Commun."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/14\/2692\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:27:50Z","timestamp":1760164070000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/14\/2692"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,7,8]]},"references-count":31,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2021,7]]}},"alternative-id":["rs13142692"],"URL":"https:\/\/doi.org\/10.3390\/rs13142692","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,7,8]]}}}