Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet
This study aims to demonstrate that the spatial and seasonal effects of daily temperature variability in positive degree-day (PDD) models play a decisive role in shaping the modeled surface mass balance (SMB) of continental-scale ice masses. Here we derive monthly fields of daily temperature standar...
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ftcopernicus:oai:publications.copernicus.org:tc20717 2023-05-15T16:26:39+02:00 Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet Rogozhina, I. Rau, D. 2018-09-27 application/pdf https://doi.org/10.5194/tc-8-575-2014 https://tc.copernicus.org/articles/8/575/2014/ eng eng doi:10.5194/tc-8-575-2014 https://tc.copernicus.org/articles/8/575/2014/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-8-575-2014 2020-07-20T16:25:08Z This study aims to demonstrate that the spatial and seasonal effects of daily temperature variability in positive degree-day (PDD) models play a decisive role in shaping the modeled surface mass balance (SMB) of continental-scale ice masses. Here we derive monthly fields of daily temperature standard deviation (SD) across Greenland from the ERA-40 (European Centre for Medium-Range Weather Forecasts 40 yr Reanalysis) reanalysis spanning from 1958 to 2001 and apply these fields to model recent surface responses of the Greenland Ice Sheet (GIS). Neither the climate data set analyzed nor in situ measurements taken in Greenland support the range of commonly used spatially and temporally uniform SD values (~ 5 °C). In this region, the SD distribution is highly inhomogeneous and characterized by low values during summer months (~ 1 to 2.5 °C) in areas where most surface melting occurs. As a result, existing SMB parameterizations using uniform, high SD values fail to capture both the spatial pattern and amplitude of the observed surface responses of the GIS. Using realistic SD values enables significant improvements in the modeled regional and total SMB with respect to existing estimates from recent satellite observations and the results of a high-resolution regional model. In addition, this resolves large uncertainties associated with other major parameters of a PDD model, namely degree-day factors. The model appears to be nearly insensitive to the choice of degree-day factors after adopting the realistic SD distribution. Text Greenland Ice Sheet Copernicus Publications: E-Journals Greenland The Cryosphere 8 2 575 585 |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
This study aims to demonstrate that the spatial and seasonal effects of daily temperature variability in positive degree-day (PDD) models play a decisive role in shaping the modeled surface mass balance (SMB) of continental-scale ice masses. Here we derive monthly fields of daily temperature standard deviation (SD) across Greenland from the ERA-40 (European Centre for Medium-Range Weather Forecasts 40 yr Reanalysis) reanalysis spanning from 1958 to 2001 and apply these fields to model recent surface responses of the Greenland Ice Sheet (GIS). Neither the climate data set analyzed nor in situ measurements taken in Greenland support the range of commonly used spatially and temporally uniform SD values (~ 5 °C). In this region, the SD distribution is highly inhomogeneous and characterized by low values during summer months (~ 1 to 2.5 °C) in areas where most surface melting occurs. As a result, existing SMB parameterizations using uniform, high SD values fail to capture both the spatial pattern and amplitude of the observed surface responses of the GIS. Using realistic SD values enables significant improvements in the modeled regional and total SMB with respect to existing estimates from recent satellite observations and the results of a high-resolution regional model. In addition, this resolves large uncertainties associated with other major parameters of a PDD model, namely degree-day factors. The model appears to be nearly insensitive to the choice of degree-day factors after adopting the realistic SD distribution. |
format |
Text |
author |
Rogozhina, I. Rau, D. |
spellingShingle |
Rogozhina, I. Rau, D. Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
author_facet |
Rogozhina, I. Rau, D. |
author_sort |
Rogozhina, I. |
title |
Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
title_short |
Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
title_full |
Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
title_fullStr |
Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
title_full_unstemmed |
Vital role of daily temperature variability in surface mass balance parameterizations of the Greenland Ice Sheet |
title_sort |
vital role of daily temperature variability in surface mass balance parameterizations of the greenland ice sheet |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-8-575-2014 https://tc.copernicus.org/articles/8/575/2014/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-8-575-2014 https://tc.copernicus.org/articles/8/575/2014/ |
op_doi |
https://doi.org/10.5194/tc-8-575-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
2 |
container_start_page |
575 |
op_container_end_page |
585 |
_version_ |
1766015583380307968 |