{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T00:01:22Z","timestamp":1773273682368,"version":"3.50.1"},"reference-count":58,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2021,3,12]],"date-time":"2021-03-12T00:00:00Z","timestamp":1615507200000},"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>For summer-accumulation-type glaciers, the glaciological literature is lacking studies on determining the snow line altitude (SLA) from optical images at the end of the summer as an indicator of the equilibrium line altitude (ELA). This paper presents a workflow for extracting the SLA from Landsat images based on the variation in the albedo with the altitude in the central line area of glaciers. The correlation of &gt;0.8 at the 99% confidence level between the retrieved SLAs with ELAs derived from the interpolation of ground-based, mass balance measurements indicated that the workflow can be applied to derive the SLA from end-of-summer satellite data as an indicator of ELA. The ELA was under-estimated by the calculated SLA. The relationship between the end-of-summer SLA and the ELA depends on the intensity of glacier melting. Subsequently, the workflow was applied to the seven glaciers in the Eastern Tien Shan Mountains, and a time series of the SLA was obtained using 12 end-of-summer Landsat scenes from 1994 to 2016. Over the whole study period, a mean SLA of 4011.6 \u00b1 20.7 m above sea level (a.s.l.) was derived for the seven investigated glaciers, and an increasing SLA was demonstrated. The increase in SLAs was consistent for the seven glaciers from 1994 to 2016. Concerning the spatial variability, the east\u2013west difference was prominent, and these differences exhibited a decreasing trend. The average SLA of each glacier is more influenced by its morpho-topographic variables. The interannual variations in the average SLA are mainly driven by the increasing summer air temperature, and the high correlation with the cumulative summer solid precipitation reflects the characteristics of the summer-accumulation-type glaciers.<\/jats:p>","DOI":"10.3390\/rs13061080","type":"journal-article","created":{"date-parts":[[2021,3,14]],"date-time":"2021-03-14T23:52:06Z","timestamp":1615765926000},"page":"1080","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Changes in the End-of-Summer Snow Line Altitude of Summer-Accumulation-Type Glaciers in the Eastern Tien Shan Mountains from 1994 to 2016"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4672-8059","authenticated-orcid":false,"given":"Xiaoying","family":"Yue","sequence":"first","affiliation":[{"name":"State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Zhongqin","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"},{"name":"College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730000, China"}]},{"given":"Jun","family":"Zhao","sequence":"additional","affiliation":[{"name":"College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730000, China"}]},{"given":"Huilin","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Puyu","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]},{"given":"Lin","family":"Wang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,3,12]]},"reference":[{"key":"ref_1","unstructured":"Stocker, T.F., Qin, D., Plattner, G.K., Tignor, M.M.B., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P.M. (2013). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press."},{"key":"ref_2","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_3","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1038\/s41586-019-1071-0","article-title":"Global glacier mass changes and their contributions to sea-level rise from 1961 to 2016","volume":"568","author":"Zemp","year":"2019","journal-title":"Nature."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Rastner, P., Prinz, R., Notarnicola, C., Nicholson, L., Sailer, R., Schwaizer, G., and Paul, F. (2019). On the Automated Mapping of Snow Cover on Glaciers and Calculation of Snow Line Altitudes from Multi-Temporal Landsat Data. Remote Sens., 11.","DOI":"10.3390\/rs11121410"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"539","DOI":"10.3189\/172756505781829106","article-title":"Using remote-sensing data to determine equilibrium-line altitude and mass-balance time series validation on three French glaciers, 1994\u20132002","volume":"51","author":"Rabatel","year":"2005","journal-title":"J. Glaciol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"307","DOI":"10.3189\/002214308784886063","article-title":"25 years (1981\u20132005) of equilibrium-line altitude and mass-balance reconstruction on Glacier Blanc, French Alps, using remote-sensing methods and meteorological data","volume":"54","author":"Rabatel","year":"2008","journal-title":"J. Glaciol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1017\/jog.2016.113","article-title":"Spatio-temporal changes in glacier wide mass balance quantified by optical remote sensing on 30 glaciers in the French Alps for the period 1983\u20132014","volume":"62","author":"Rabatel","year":"2016","journal-title":"J. Glaciol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1657\/1938-4246-41.2.174","article-title":"Satellite derived equilibrium lines in Northern Patagonia Icefield, Chile and Their Implications to Glacier Variations","volume":"41","author":"Barcaza","year":"2009","journal-title":"Arct. Antarct. Alp. Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1027","DOI":"10.3189\/2012JoG12J027","article-title":"Can the snowline be used as an indicator of the equilibrium line and mass balance for glaciers in the outer tropics?","volume":"58","author":"Rabatel","year":"2012","journal-title":"J. Glaciol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"419","DOI":"10.5194\/tc-5-419-2011","article-title":"Landsat TM and ETM+ Derived Snowline Altitudes in the Cordillera Huayhuash and Cordillera Raura, Peru, 1986\u20132005","volume":"5","author":"Mcfadden","year":"2011","journal-title":"Cryosphere"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1007\/s00704-016-1775-0","article-title":"Recent trends in annual snowline variations in the northern wet outer tropics: Case studies from southern Cordillera Blanca, Peru","volume":"129","author":"Veettil","year":"2017","journal-title":"Theor. Appl. Climatol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1002\/joc.722","article-title":"Interannual variation in end-of summer snowlines of the southern Alps of New Zealand, and relationships with southern Hemisphere atmospheric circulation and sea surface temperature patterns","volume":"22","author":"Clare","year":"2002","journal-title":"Int. J. Climatol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1455","DOI":"10.5194\/tc-7-1455-2013","article-title":"Changes in glacier equilibrium-line altitude in the western Alps from 1984 to 2010 evaluation by remote sensing and modeling of the morpho-topographic and climate controls","volume":"7","author":"Rabate","year":"2013","journal-title":"Cryosphere"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"104","DOI":"10.3189\/S0260305500000471","article-title":"Characterization of snow and ice reflectance zones on glaciers using Landsat Thematic Mapper data","volume":"9","author":"Hall","year":"1987","journal-title":"Ann. Glaciol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.gloplacha.2006.11.032","article-title":"Snow zonation on Hielo Patag\u00f3nico Sur, Southern Patagonia, derived from Landsat 5 TM data","volume":"59","author":"Rau","year":"2007","journal-title":"Glob. Planet. Chang."},{"key":"ref_16","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":"Crypsphere"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1016\/j.rse.2003.10.016","article-title":"Estimating fractional snow cover from MODIS using normalized difference snow index","volume":"89","author":"Salomonson","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/S0921-8181(99)00032-6","article-title":"Spectral mixture analysis of Landsat thematic mapper images applied to the detection of the transient snowline on tropical Andean glaciers","volume":"22","author":"Klein","year":"1999","journal-title":"Glob. Planet. Chang."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"359","DOI":"10.5194\/tc-8-359-2014","article-title":"Glacial area, lake areas, and snow lines from 1975 to 2012: Status of the Cordillera Vilcanota, including the Quelccaya Ice Cap, northern central Andes, Peru","volume":"8","author":"Hanshaw","year":"2014","journal-title":"Crypsphere"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/j.gloplacha.2014.03.012","article-title":"Temporal and spatial changes in Western Himalayan firn line altitudes from 1998 to 2009","volume":"118","author":"Guo","year":"2014","journal-title":"Glob. Planet. Chang."},{"key":"ref_21","first-page":"1594","article-title":"Spatial-temporal variation of glacier resources in Chinese Tianshan Mountains since 1959","volume":"72","author":"Xing","year":"2017","journal-title":"Acta Geogr. Sinica"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.quaint.2013.08.035","article-title":"Rapid decrease of observed mass balance in the Urumqi Glacier No. 1, Tianshan Mountains, central Asia","volume":"349","author":"Zhang","year":"2014","journal-title":"Quat. Int."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1016\/j.atmosres.2017.12.007","article-title":"Detection of spatio-temporal variability of air temperature and precipitation based on long-term meteorological station observations over Tianshan Mountains, Central Asia","volume":"203","author":"Xu","year":"2018","journal-title":"Atmos. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1038\/ngeo2513","article-title":"Substantial glacier mass loss in the Tian Shan over the past 50 years","volume":"8","author":"Farinotti","year":"2015","journal-title":"Nat. Geosci."},{"key":"ref_25","first-page":"258","article-title":"Characteristics of precipitation in the source area of the Urumqi River Basin","volume":"14","author":"Yang","year":"1992","journal-title":"J. Glaciol. Geocryol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s12583-011-0194-5","article-title":"Mechanisms and Simulation of Accelerated Shrinkage of Continental Glaciers A Case Study of Urumqi Glacier No. 1 in Eastern Tianshan, Central Asia","volume":"22","author":"Li","year":"2011","journal-title":"J. Earth Sci."},{"key":"ref_27","first-page":"61","article-title":"Characteristics of Mass Balance of Summer\u2014Accumulation Type Glaciers in the Himalayas and Tibetan Plateau","volume":"32","author":"Ageta","year":"1996","journal-title":"Zeitschrift F\u00fcr Gletscherkunde und Glazialgeologie"},{"key":"ref_28","unstructured":"Tachikawa, T., Kaku, M., Iwasaki, A., Gesch, D., Oimoen, M., Zhang, Z., Danielson, J., Krieger, T., Curtis, B., and Haase, J. (2011). ASTER Global Digital Elevation Model Version 2\u2014Summary of Validation Results. NASA Land Processes."},{"key":"ref_29","unstructured":"World Glacier Monitoring Service (WGMS) (2013). Global Glacier Change Bulletin No. 1\u20133 (2013\u20132017), World Glacier Monitoring Service."},{"key":"ref_30","unstructured":"World Glacier Monitoring Service (WGMS) (2013). Glacier Mass Balance Bulletins Vols 4\u201312 (1994\u20132012), World Glacier Monitoring Service."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Zemp, M., Hoelzle, W., and Haeberli, W. (2009). Six decades of glacier mass-balance observations a review of the worldwide monitoring network. Ann. Glaciol., 101\u2013111.","DOI":"10.3189\/172756409787769591"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"649","DOI":"10.3189\/172756501781831783","article-title":"Quantifying the effects of climate and surface change on glacier mass balance","volume":"47","author":"Elsberg","year":"2001","journal-title":"J. Glaciol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2361","DOI":"10.5194\/tc-13-2361-2019","article-title":"Long-range terrestrial laser scanning measurements of annual and intra-annual mass balances for Urumqi Glacier No. 1, eastern Tien Shan, China","volume":"13","author":"Xu","year":"2019","journal-title":"Cryosphere."},{"key":"ref_34","first-page":"925","article-title":"Study on energy-water-mass balance and the hydrological flow model in a glacierized catchment of Tianshan mountain","volume":"38","author":"Kang","year":"1993","journal-title":"Chin. Sci. Bull."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Wang, P., Li, Z., Schneider, C., Li, H., Hamm, A., Jing, S., Xu, C., Li, H., Yue, X., and Yang, M. (2020). A test study of an energy and mass balance model application to a site on Urumqi Glacier No. 1, Chinese Tian Shan. Water, 12.","DOI":"10.3390\/w12102865"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1017\/jog.2017.57","article-title":"Spatial and temporal variations of the surface albedo and other factors influencing Urumqi Glacier No. 1 in Tien Shan, China","volume":"63","author":"Yue","year":"2017","journal-title":"J. Glaciol."},{"key":"ref_37","first-page":"1124","article-title":"An improved topographic correction approach for satellite image","volume":"10","author":"Hang","year":"2005","journal-title":"J. Image Graph."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/S0034-4257(99)00043-7","article-title":"Anisotropic reflection of melting glacier ice: Measurements and parameterizations","volume":"70","author":"Greuell","year":"1999","journal-title":"Remote Sens. Environ."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"9661","DOI":"10.1029\/2000JD900718","article-title":"Surface albedo measurements over snow blue ice in thematic mapper bands 2 and 4 Dronning Maud Land, Antarctica","volume":"106","author":"Reijmer","year":"2001","journal-title":"J. Geophys. Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2091","DOI":"10.1080\/014311699212362","article-title":"Narrowband to broadband conversion of Landsat TM glacier albedos","volume":"20","author":"Knap","year":"1999","journal-title":"Int. J. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"491","DOI":"10.3189\/172756503781830395","article-title":"Temporal and spatial variation of the surface albedo of Morteratschgletscher, Switzerland, as derived from 12 Landsat images","volume":"49","author":"Klok","year":"2003","journal-title":"J. Glaciol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.coldregions.2016.02.006","article-title":"Spatial ditribution of surface albedo at the Forni Glacier (Stelvio National Park, Central Italian Alpa)","volume":"125","author":"Fugazza","year":"2016","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3293","DOI":"10.1080\/014311699211345","article-title":"Comparison of Landsat TM-derived and ground based albedos of Haut Glacier d\u2019Arolla, Switzerland","volume":"20","author":"Knap","year":"1999","journal-title":"Int. J. Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3454","DOI":"10.1002\/hyp.9883","article-title":"Spatial and temporal variations of albedo on nine glaciers in western China from 2000 to 2011","volume":"28","author":"Wang","year":"2014","journal-title":"Hydrol. Process."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"397","DOI":"10.5194\/tc-13-397-2019","article-title":"Change detection of bare-ice albedo in the Swiss Alps","volume":"13","author":"Naegeli","year":"2019","journal-title":"Cryosphere"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/j.cageo.2012.10.014","article-title":"An automatic method to create flow lines for determination of glacier length: A pilot study with Alaskan glaciers","volume":"52","author":"Paul","year":"2013","journal-title":"Comput. Geosci."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"110","DOI":"10.3389\/feart.2020.00110","article-title":"Variation in Albedo and its Relationship with Surface Dust at Urumqi Glacier No. 1 in Tien Shan, China","volume":"8","author":"Yue","year":"2020","journal-title":"Front. Earth Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1007\/s12665-016-5551-3","article-title":"Analyses of recent observations of Urumqi Glacier No. 1, Chinese Tianshan Mountains","volume":"75","author":"Wang","year":"2016","journal-title":"Environ. Earth Sci."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.3189\/2014JoG13J221","article-title":"Limitations in identifying the equilibrium-line altitude from the optical remote-sensing derived snowline in the Tien Shan, China","volume":"60","author":"Wu","year":"2014","journal-title":"J. Glaciol."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1657\/AAAR00C-13-303","article-title":"Variations in firn line altitude and firn zone area on Qiyi Glacier, Qilian Mountains, over the period of 1990 to 2011","volume":"47","author":"Guo","year":"2015","journal-title":"Arct. Antact. Alp. Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2820","DOI":"10.1007\/s11434-011-4621-x","article-title":"Changes in physical features of Glacier No. 1 of the Tianshan Mountains in response to climate change","volume":"56","author":"Li","year":"2011","journal-title":"Chin. Sci. Bull."},{"key":"ref_52","first-page":"825","article-title":"Variations in the equilibrium line altitude of Urumqi Glacier No.1, Tianshan Mountains, over the past 50 years","volume":"58","author":"Dong","year":"2013","journal-title":"Chinese. Sci. Bull."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"3810","DOI":"10.1007\/s11434-010-4167-3","article-title":"Variations in equilibrium line altitude of the Qiyi Glacier, Qilian Mountains, over the past 50 years","volume":"55","author":"Wang","year":"2010","journal-title":"Chin. Sci. Bull."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.gloplacha.2006.07.002","article-title":"Distributed modelling of the regional climatic equilibrium line altitude of glaciers in the European Alps","volume":"56","author":"Zemp","year":"2007","journal-title":"Glob. Planet. Chang."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.coldregions.2018.08.006","article-title":"Detailed comparison of glaciological and geodetic mass balances for Urumqi Glacier No.1, eastern Tien Shan, China, from 1981 to 2015","volume":"155","author":"Xu","year":"2018","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_56","first-page":"137","article-title":"A review of snow and ice albedo and the development of a new physically based broadband albedo parameterization","volume":"115","author":"Gardner","year":"2010","journal-title":"J. Geophys. Res."},{"key":"ref_57","unstructured":"Cuffey, K.M., and Paterson, W.S.B. (2010). The Physical of Glacier, Elsevier. [4nd ed.]."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Zhao, Y., Zhao, J., Yue, X., and Wang, Y. (2021, March 01). Comparison of Remote Sensing Extraction Methods for Glacier Firn Line- Considering Urumqi Glacier No.1 as the Experimental Area. Available online: https:\/\/www.e3s-conferences.org\/articles\/e3sconf\/abs\/2020\/78\/e3sconf_iseese2020_04024\/e3sconf_iseese2020_04024.html.","DOI":"10.1051\/e3sconf\/202021804024"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/6\/1080\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:34:52Z","timestamp":1760160892000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/6\/1080"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,12]]},"references-count":58,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2021,3]]}},"alternative-id":["rs13061080"],"URL":"https:\/\/doi.org\/10.3390\/rs13061080","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,12]]}}}