A simple physics-based improvement to the positive degree day model
Meltwater is important to understanding glacier health and dynamics. Since melt measurements are uncommon, ice ablation estimates are often based on models including the positive degree day (PDD) model. The PDD estimate is popular since it only requires air temperature as input, but suffers from the...
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Cambridge University Press
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ftdoajarticles:oai:doaj.org/article:3ccecca28b2c41c99ca55470e64362e3 2023-05-15T16:21:26+02:00 A simple physics-based improvement to the positive degree day model VICTOR C. TSAI XIAOZHOU RUAN 2018-08-01T00:00:00Z https://doi.org/10.1017/jog.2018.55 https://doaj.org/article/3ccecca28b2c41c99ca55470e64362e3 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143018000552/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.55 0022-1430 1727-5652 https://doaj.org/article/3ccecca28b2c41c99ca55470e64362e3 Journal of Glaciology, Vol 64, Pp 661-668 (2018) energy balance glacier ablation phenomena melt-surface Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2018 ftdoajarticles https://doi.org/10.1017/jog.2018.55 2023-03-12T01:30:59Z Meltwater is important to understanding glacier health and dynamics. Since melt measurements are uncommon, ice ablation estimates are often based on models including the positive degree day (PDD) model. The PDD estimate is popular since it only requires air temperature as input, but suffers from the lack of physical motivation of an energy-balance model. We present a physics-based alternative to the PDD model that still only takes air/surface temperature as input. The model resembles the PDD model except accounting for time lags in ablation when cold ice needs to be warmed. The model is expressed as a differential equation with a single extra parameter related to the efficiency of heating a near-surface layer of ice. With zero thickness, the model reduces to the PDD model, providing a physical basis for the PDD model. Applying the model to data from Greenland, it improves modestly upon the PDD model, with the main improvement being better prediction of early season melting. This new model is a useful compromise, with some of the physics of more realistic models and the simplicity of a PDD model. The model should improve estimates of meltwater production and help constrain PDD parameters when empirical calibration is challenging. Article in Journal/Newspaper glacier Greenland Journal of Glaciology Directory of Open Access Journals: DOAJ Articles Greenland Journal of Glaciology 64 246 661 668 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
energy balance glacier ablation phenomena melt-surface Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
energy balance glacier ablation phenomena melt-surface Environmental sciences GE1-350 Meteorology. Climatology QC851-999 VICTOR C. TSAI XIAOZHOU RUAN A simple physics-based improvement to the positive degree day model |
topic_facet |
energy balance glacier ablation phenomena melt-surface Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Meltwater is important to understanding glacier health and dynamics. Since melt measurements are uncommon, ice ablation estimates are often based on models including the positive degree day (PDD) model. The PDD estimate is popular since it only requires air temperature as input, but suffers from the lack of physical motivation of an energy-balance model. We present a physics-based alternative to the PDD model that still only takes air/surface temperature as input. The model resembles the PDD model except accounting for time lags in ablation when cold ice needs to be warmed. The model is expressed as a differential equation with a single extra parameter related to the efficiency of heating a near-surface layer of ice. With zero thickness, the model reduces to the PDD model, providing a physical basis for the PDD model. Applying the model to data from Greenland, it improves modestly upon the PDD model, with the main improvement being better prediction of early season melting. This new model is a useful compromise, with some of the physics of more realistic models and the simplicity of a PDD model. The model should improve estimates of meltwater production and help constrain PDD parameters when empirical calibration is challenging. |
format |
Article in Journal/Newspaper |
author |
VICTOR C. TSAI XIAOZHOU RUAN |
author_facet |
VICTOR C. TSAI XIAOZHOU RUAN |
author_sort |
VICTOR C. TSAI |
title |
A simple physics-based improvement to the positive degree day model |
title_short |
A simple physics-based improvement to the positive degree day model |
title_full |
A simple physics-based improvement to the positive degree day model |
title_fullStr |
A simple physics-based improvement to the positive degree day model |
title_full_unstemmed |
A simple physics-based improvement to the positive degree day model |
title_sort |
simple physics-based improvement to the positive degree day model |
publisher |
Cambridge University Press |
publishDate |
2018 |
url |
https://doi.org/10.1017/jog.2018.55 https://doaj.org/article/3ccecca28b2c41c99ca55470e64362e3 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Journal of Glaciology |
genre_facet |
glacier Greenland Journal of Glaciology |
op_source |
Journal of Glaciology, Vol 64, Pp 661-668 (2018) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143018000552/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.55 0022-1430 1727-5652 https://doaj.org/article/3ccecca28b2c41c99ca55470e64362e3 |
op_doi |
https://doi.org/10.1017/jog.2018.55 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
246 |
container_start_page |
661 |
op_container_end_page |
668 |
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1766009430591143936 |