The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling

The sensitivity of the mass balance of the Greenland ice sheet to climate change is studied with an energy-balance model of the ice/snow surface, applied at 200 m elevation intervals for four characteristic regions of the ice sheet. Solar radiation, longwave radiation, turbulent heat fluxes and refr...

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Main Author: Oerlemans, J.
Format: Article in Journal/Newspaper
Language:English
Published: 1991
Subjects:
Online Access:https://dspace.library.uu.nl/handle/1874/22284
id ftunivutrecht:oai:dspace.library.uu.nl:1874/22284
record_format openpolar
spelling ftunivutrecht:oai:dspace.library.uu.nl:1874/22284 2023-07-23T04:19:23+02:00 The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling Oerlemans, J. 1991 image/pdf https://dspace.library.uu.nl/handle/1874/22284 en eng 0959-6836 https://dspace.library.uu.nl/handle/1874/22284 info:eu-repo/semantics/OpenAccess Natuur- en Sterrenkunde energy-balance modelling Greenland ice sheet mass balance climate change orbital effects Holocene Article 1991 ftunivutrecht 2023-07-01T23:20:35Z The sensitivity of the mass balance of the Greenland ice sheet to climate change is studied with an energy-balance model of the ice/snow surface, applied at 200 m elevation intervals for four characteristic regions of the ice sheet. Solar radiation, longwave radiation, turbulent heat fluxes and refreezing of melt water in the snow pack are treated separately. The daily cycle is fully resolved. For the climatology chosen as input (mainly from work by A. Ohmura), the, mean specific balance produced by the model is 0.079 m/yr (water equivalent). Comparing this with the total accumulation, 0.313 m/yr, it, is obvious that the ablation is quite large. However, a 1 K decrease of the imposed annual mean temperature leads to a specific balance of 0.147 m/yr, a 1 K increase to 0.003 m/yr. Because of this large sensitivity, it appears that the present state of balance cannot be determined from climatological data. The calculations show that changes in the earth's orbit during the Holocene must have had a significant effect on the mean specific balance of the Greenland ice sheet. The balance was smaller than today during most of the last 10 000 years, probably by as much as 0.05 m/yr. Further experimentation showed that the changes in the specific balance can be related to changes in summer insolation. The difference between a typical high latitude minimum in insolation (e.g., 25 000 BP) and a high latitude maximum in insolation (e.g., 10 000 BP) is equivalent to the effect of a 2 K difference in annual mean temperature. So when considering mass balance changes for a particular glacier during the Holocene, it is important to consider the orbital and climatic effects separately, because they may work in the same or in the opposite direction, depending on the location. In a warmer world, ablation will increase, but this will be compensated to some extent by increased snowfall. For a uniform warming of 1 K, and including a precipitation rate proportional to maximum possible atmospheric water content, the model predicts a ... Article in Journal/Newspaper glacier Greenland Ice Sheet Utrecht University Repository Greenland
institution Open Polar
collection Utrecht University Repository
op_collection_id ftunivutrecht
language English
topic Natuur- en Sterrenkunde
energy-balance modelling
Greenland ice sheet
mass balance
climate change
orbital effects
Holocene
spellingShingle Natuur- en Sterrenkunde
energy-balance modelling
Greenland ice sheet
mass balance
climate change
orbital effects
Holocene
Oerlemans, J.
The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
topic_facet Natuur- en Sterrenkunde
energy-balance modelling
Greenland ice sheet
mass balance
climate change
orbital effects
Holocene
description The sensitivity of the mass balance of the Greenland ice sheet to climate change is studied with an energy-balance model of the ice/snow surface, applied at 200 m elevation intervals for four characteristic regions of the ice sheet. Solar radiation, longwave radiation, turbulent heat fluxes and refreezing of melt water in the snow pack are treated separately. The daily cycle is fully resolved. For the climatology chosen as input (mainly from work by A. Ohmura), the, mean specific balance produced by the model is 0.079 m/yr (water equivalent). Comparing this with the total accumulation, 0.313 m/yr, it, is obvious that the ablation is quite large. However, a 1 K decrease of the imposed annual mean temperature leads to a specific balance of 0.147 m/yr, a 1 K increase to 0.003 m/yr. Because of this large sensitivity, it appears that the present state of balance cannot be determined from climatological data. The calculations show that changes in the earth's orbit during the Holocene must have had a significant effect on the mean specific balance of the Greenland ice sheet. The balance was smaller than today during most of the last 10 000 years, probably by as much as 0.05 m/yr. Further experimentation showed that the changes in the specific balance can be related to changes in summer insolation. The difference between a typical high latitude minimum in insolation (e.g., 25 000 BP) and a high latitude maximum in insolation (e.g., 10 000 BP) is equivalent to the effect of a 2 K difference in annual mean temperature. So when considering mass balance changes for a particular glacier during the Holocene, it is important to consider the orbital and climatic effects separately, because they may work in the same or in the opposite direction, depending on the location. In a warmer world, ablation will increase, but this will be compensated to some extent by increased snowfall. For a uniform warming of 1 K, and including a precipitation rate proportional to maximum possible atmospheric water content, the model predicts a ...
format Article in Journal/Newspaper
author Oerlemans, J.
author_facet Oerlemans, J.
author_sort Oerlemans, J.
title The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
title_short The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
title_full The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
title_fullStr The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
title_full_unstemmed The mass balance of the Greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
title_sort mass balance of the greenland ice sheet: sensitivity to climate change as revealed by energy-balance modelling
publishDate 1991
url https://dspace.library.uu.nl/handle/1874/22284
geographic Greenland
geographic_facet Greenland
genre glacier
Greenland
Ice Sheet
genre_facet glacier
Greenland
Ice Sheet
op_relation 0959-6836
https://dspace.library.uu.nl/handle/1874/22284
op_rights info:eu-repo/semantics/OpenAccess
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