An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America
We describe a method to calculate regional snow line elevations and annual equilibrium line altitudes (ELAs) from daily MODIS imagery (MOD02QKM) on large glaciers and icefields in western North America. An automated cluster analysis of the cloud-masked visible and near-infrared bands at 250 m resolu...
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2013
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Online Access: | https://doi.org/10.5194/tc-7-667-2013 http://www.the-cryosphere.net/7/667/2013/tc-7-667-2013.pdf https://doaj.org/article/969a82fbe0f642229c521dd07bf46cd5 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:969a82fbe0f642229c521dd07bf46cd5 2023-05-15T18:32:21+02:00 An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America J. M. Shea B. Menounos R. D. Moore C. Tennant 2013-04-01 https://doi.org/10.5194/tc-7-667-2013 http://www.the-cryosphere.net/7/667/2013/tc-7-667-2013.pdf https://doaj.org/article/969a82fbe0f642229c521dd07bf46cd5 en eng Copernicus Publications doi:10.5194/tc-7-667-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/667/2013/tc-7-667-2013.pdf https://doaj.org/article/969a82fbe0f642229c521dd07bf46cd5 undefined The Cryosphere, Vol 7, Iss 2, Pp 667-680 (2013) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2013 fttriple https://doi.org/10.5194/tc-7-667-2013 2023-01-22T18:58:51Z We describe a method to calculate regional snow line elevations and annual equilibrium line altitudes (ELAs) from daily MODIS imagery (MOD02QKM) on large glaciers and icefields in western North America. An automated cluster analysis of the cloud-masked visible and near-infrared bands at 250 m resolution is used to delineate glacier facies (snow and ice) for ten glacierized regions between 2000–2011. For each region and season, the maximum observed value of the 20th percentile of snow-covered pixels (ZS(20)) is used to define a regional ELA proxy (ELAest). Our results indicate significant increases in the regional ELA proxy at two continental sites (Peyto Glacier and Gulkana Glacier) over the period of observation, though no statistically significant trends are identified at other sites. To evaluate the utility of regional ELA proxies derived from MOD02QKM imagery, we compare standard geodetic estimates of glacier mass change with estimates derived from historical mass balance gradients and observations of ZS(20) at three large icefields. Our approach yields estimates of mass change that more negative than traditional geodetic approaches, though MODIS-derived estimates are within the margins of error at all three sites. Both estimates of glacier mass change corroborate the continued mass loss of glaciers in western North America. Between 2000 and 2009, the geodetic change approach yields mean annual rates of surface elevation change for the Columbia, Lillooet, and Sittakanay icefields of −0.29 ± 0.05, −0.26 ± 0.05, and −0.63 ± 0.17 m a−1, respectively. This study provides a new technique for glacier facies detection at daily timescales, and contributes to the development of regional estimates of glacier mass change, both of which are critical for studies of glacier contributions to streamflow and global sea level rise. Article in Journal/Newspaper The Cryosphere Unknown Ela ENVELOPE(9.642,9.642,63.170,63.170) The Cryosphere 7 2 667 680 |
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Open Polar |
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fttriple |
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English |
topic |
geo envir |
spellingShingle |
geo envir J. M. Shea B. Menounos R. D. Moore C. Tennant An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
topic_facet |
geo envir |
description |
We describe a method to calculate regional snow line elevations and annual equilibrium line altitudes (ELAs) from daily MODIS imagery (MOD02QKM) on large glaciers and icefields in western North America. An automated cluster analysis of the cloud-masked visible and near-infrared bands at 250 m resolution is used to delineate glacier facies (snow and ice) for ten glacierized regions between 2000–2011. For each region and season, the maximum observed value of the 20th percentile of snow-covered pixels (ZS(20)) is used to define a regional ELA proxy (ELAest). Our results indicate significant increases in the regional ELA proxy at two continental sites (Peyto Glacier and Gulkana Glacier) over the period of observation, though no statistically significant trends are identified at other sites. To evaluate the utility of regional ELA proxies derived from MOD02QKM imagery, we compare standard geodetic estimates of glacier mass change with estimates derived from historical mass balance gradients and observations of ZS(20) at three large icefields. Our approach yields estimates of mass change that more negative than traditional geodetic approaches, though MODIS-derived estimates are within the margins of error at all three sites. Both estimates of glacier mass change corroborate the continued mass loss of glaciers in western North America. Between 2000 and 2009, the geodetic change approach yields mean annual rates of surface elevation change for the Columbia, Lillooet, and Sittakanay icefields of −0.29 ± 0.05, −0.26 ± 0.05, and −0.63 ± 0.17 m a−1, respectively. This study provides a new technique for glacier facies detection at daily timescales, and contributes to the development of regional estimates of glacier mass change, both of which are critical for studies of glacier contributions to streamflow and global sea level rise. |
format |
Article in Journal/Newspaper |
author |
J. M. Shea B. Menounos R. D. Moore C. Tennant |
author_facet |
J. M. Shea B. Menounos R. D. Moore C. Tennant |
author_sort |
J. M. Shea |
title |
An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
title_short |
An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
title_full |
An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
title_fullStr |
An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
title_full_unstemmed |
An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America |
title_sort |
approach to derive regional snow lines and glacier mass change from modis imagery, western north america |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/tc-7-667-2013 http://www.the-cryosphere.net/7/667/2013/tc-7-667-2013.pdf https://doaj.org/article/969a82fbe0f642229c521dd07bf46cd5 |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Ela |
geographic_facet |
Ela |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 7, Iss 2, Pp 667-680 (2013) |
op_relation |
doi:10.5194/tc-7-667-2013 1994-0416 1994-0424 http://www.the-cryosphere.net/7/667/2013/tc-7-667-2013.pdf https://doaj.org/article/969a82fbe0f642229c521dd07bf46cd5 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-7-667-2013 |
container_title |
The Cryosphere |
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7 |
container_issue |
2 |
container_start_page |
667 |
op_container_end_page |
680 |
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