Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier
Glaciological ablation is computed from point-scale data at a few ablation stakes that are usually regressed as a function of elevation and averaged over the area-elevation distribution of a glacier. This method is contingent on a tight control of elevation on local ablation. However, in debris-cove...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2019-10-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143019000480/type/journal_article |
| _version_ | 1811155815600488448 |
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| author | Sunil Singh Shah Argha Banerjee Harish Chandra Nainwal R. Shankar |
| author_facet | Sunil Singh Shah Argha Banerjee Harish Chandra Nainwal R. Shankar |
| author_sort | Sunil Singh Shah |
| collection | DOAJ |
| description | Glaciological ablation is computed from point-scale data at a few ablation stakes that are usually regressed as a function of elevation and averaged over the area-elevation distribution of a glacier. This method is contingent on a tight control of elevation on local ablation. However, in debris-covered glaciers, systematic and random spatial variations of debris thickness modify the ablation rates. We propose and test a method to compute sub-debris ablation where stake data are interpolated as a function of debris-thickness alone and averaged over the debris-thickness distribution at different parts of the glacier. We apply this method on Satopanth Glacier located in Central Himalaya utilising ~1000 ablation measurements obtained from a network of up to 56 stakes during 2015–2017. The estimated mean sub-debris ablation ranges between 1.5±0.2 to 1.7±0.3 cm d−1. We show that the debris-thickness-dependent regression describes the spatial variability of the sub-debris ablation better than the elevation dependent regression. The uncertainties in ablation estimates due to the corresponding uncertainties in the measurement of ablation and debris-thickness distribution, and those due to interpolation procedures are estimated using Monte Carlo methods. Possible biases due to a finite number of stakes used are also investigated. |
| first_indexed | 2024-04-10T04:41:02Z |
| format | Article |
| id | doaj.art-b0323c49439a49a7b6489795a5e2b868 |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:41:02Z |
| publishDate | 2019-10-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-b0323c49439a49a7b6489795a5e2b8682023-03-09T12:40:49ZengCambridge University PressJournal of Glaciology0022-14301727-56522019-10-016575976910.1017/jog.2019.48Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacierSunil Singh Shah0Argha Banerjee1https://orcid.org/0000-0002-6007-0719Harish Chandra Nainwal2R. Shankar3Department of Geology, HNB Garhwal University, Srinagar, Uttarakhand, IndiaEarth and Climate Science, Indian Institute of Science Education and Research, Pune, IndiaDepartment of Geology, HNB Garhwal University, Srinagar, Uttarakhand, IndiaThe Institute of Mathematical Sciences, Chennai, IndiaGlaciological ablation is computed from point-scale data at a few ablation stakes that are usually regressed as a function of elevation and averaged over the area-elevation distribution of a glacier. This method is contingent on a tight control of elevation on local ablation. However, in debris-covered glaciers, systematic and random spatial variations of debris thickness modify the ablation rates. We propose and test a method to compute sub-debris ablation where stake data are interpolated as a function of debris-thickness alone and averaged over the debris-thickness distribution at different parts of the glacier. We apply this method on Satopanth Glacier located in Central Himalaya utilising ~1000 ablation measurements obtained from a network of up to 56 stakes during 2015–2017. The estimated mean sub-debris ablation ranges between 1.5±0.2 to 1.7±0.3 cm d−1. We show that the debris-thickness-dependent regression describes the spatial variability of the sub-debris ablation better than the elevation dependent regression. The uncertainties in ablation estimates due to the corresponding uncertainties in the measurement of ablation and debris-thickness distribution, and those due to interpolation procedures are estimated using Monte Carlo methods. Possible biases due to a finite number of stakes used are also investigated.https://www.cambridge.org/core/product/identifier/S0022143019000480/type/journal_articleDebris-covered glaciersglacier mass balancemelt-surfacesupraglacial debris |
| spellingShingle | Sunil Singh Shah Argha Banerjee Harish Chandra Nainwal R. Shankar Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier Journal of Glaciology Debris-covered glaciers glacier mass balance melt-surface supraglacial debris |
| title | Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier |
| title_full | Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier |
| title_fullStr | Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier |
| title_full_unstemmed | Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier |
| title_short | Estimation of the total sub-debris ablation from point-scale ablation data on a debris-covered glacier |
| title_sort | estimation of the total sub debris ablation from point scale ablation data on a debris covered glacier |
| topic | Debris-covered glaciers glacier mass balance melt-surface supraglacial debris |
| url | https://www.cambridge.org/core/product/identifier/S0022143019000480/type/journal_article |
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