Monitoring of heat exchanges in thesnowpack of Foxfonna glacier, Spitzbergen,Svalbard.
(2022) FYSK02 20212Combustion Physics
Department of Physics
- Abstract
- The processes of meltwater storage in firn and the impact of refreezing on firn-coveredglaciers have been investigated on the Greenland ice-sheet. On Svalbard, climate changepromotes the disappearance of firn on glaciers. This thesis project aims to monitor theheat exchanges between the snowpack and the ice surface on a non firn-covered glacier,on Foxfonna, Spitzbergen, Svalbard, and to draw the picture of the events occurring inthe snowpack over a melting season, from May to July 2021.This report has two aims. First, to highlight the evolution of snow properties; bulk den-sity, heat flow,Snow Water Equivalent(SWE, amount of water that would result from themelting of 1m2surface area of that snowpack), and albedo, during melting, and... (More)
- The processes of meltwater storage in firn and the impact of refreezing on firn-coveredglaciers have been investigated on the Greenland ice-sheet. On Svalbard, climate changepromotes the disappearance of firn on glaciers. This thesis project aims to monitor theheat exchanges between the snowpack and the ice surface on a non firn-covered glacier,on Foxfonna, Spitzbergen, Svalbard, and to draw the picture of the events occurring inthe snowpack over a melting season, from May to July 2021.This report has two aims. First, to highlight the evolution of snow properties; bulk den-sity, heat flow,Snow Water Equivalent(SWE, amount of water that would result from themelting of 1m2surface area of that snowpack), and albedo, during melting, and attemptsto do so during the formation of superimposed ice, e.g. refreezing of meltwater on theglacier ice. Second, to model the snow melt using local weather data and to compare themodelled results with the observed melt, measured periodically throughout the fieldworkperiod. Snow pits were dug to measure the snow temperature and density, and to observethe evolution of the snowpack properties. In the snow pits, the focus was set on the snowmetamorphism, albedo, water content and stakes measurements. Finally, stakes measure-ments were realized to assess the growth of superimposed ice.The weather data indicates a sudden warming on the 2ndof June, which rendered thesnowpack isothermal (0°C over the entire column), as observed from the snow temper-ature. The already established melt became stronger as a result of this warm event, asobserved in the snow depth data. The snow melt modelled from the 6thto the 11thofJune indicates results diverging from the actual snow melt by 95%. Nonetheless, themodel describes the main physics of the system, as it predicts that melting must occur, asexpected. The divergence between the modelled and the observed melt can be attributedto the use of weather stations located away from the site. As snow melted, the bulkdensity increased, resulting in a stronger heat flow within the snowpack over time. Theinter-comparison of the SWE and the bulk density can reveal that snow metamorphismoccurred, or that snow has accumulated on the glacier. Such inter-comparison was suc-cessfully carried out at the beginning of the fieldwork, revealing the accumulation of snowby some wind, in accordance with the snow depth and albedo data. Besides this one event,the SWE data did not reveal any clear trend over time, perhaps because of the interplaybetween the progressive melt, which should make it decrease, and the advection of waterfrom up-glacier snow, which would make the SWE increase. Likely the location of the gridin a bowl prevented the analyses of the SWE data. Finally, the formation of superimposedice was detected at the very end of the fieldwork. Its formation has been prevented bythe fact that snowpack became suddenly isothermal by this warm event. With the coldcontent of the snowpack being entirely removed, not much refreezing occurred. (Less)
- Popular Abstract
- Refreezing of meltwater in snow and firn is known to have a major impact on the mass and energy budget of glaciers. In the Arctic, it is sometimes the primary accumulation process of some glaciers. It is a major heating process, as the refreezing of 1g of water releases enough latent heat to raise the temperature of 160g of snow by 1°C.
Superimposed Ice is a layer of ice formed by the percolation of meltwater onto the sub-zero temperature glacier ice. The meltwater can percolate and transfer heat deep into the snow and the firn cover, and even reach the glacier ice surface, where the refreezing removes some of the cold content of the ice by latent release. As a fraction of the meltwater remains captured in the snow, this process may... (More) - Refreezing of meltwater in snow and firn is known to have a major impact on the mass and energy budget of glaciers. In the Arctic, it is sometimes the primary accumulation process of some glaciers. It is a major heating process, as the refreezing of 1g of water releases enough latent heat to raise the temperature of 160g of snow by 1°C.
Superimposed Ice is a layer of ice formed by the percolation of meltwater onto the sub-zero temperature glacier ice. The meltwater can percolate and transfer heat deep into the snow and the firn cover, and even reach the glacier ice surface, where the refreezing removes some of the cold content of the ice by latent release. As a fraction of the meltwater remains captured in the snow, this process may buffer the sea level rise caused by the increased glacier melt. The processes of meltwater storage in firn and the impact of
refreezing on firn-covered glaciers have been investigated on the Greenland ice sheet. On Svalbard, climate change promotes the disappearance of firn on glaciers. Gaining further knowledge about superimposed ice and the refreezing processes on a firn-free glacier is crucial for understanding and predicting the future of Arctic glaciers.
This thesis aims to monitor the heat exchanges through the snowpack on the firn-free Foxfonna glacier, Spitzbergen, Svalbard, over the melting season May-July 2021. Weather data were gathered, for multiple reasons. First, to link the weather conditions to the observed snow processes. Second, to model the snowmelt. The modelled results were compared with field data. The evolution of the snow processes as it melts was assessed by making snow pits and measuring temperature and density. The snow and the weather data
reveals that the weather and snow conditions were not appropriate for the SI formation. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9076352
- author
- Desjonquères, Thibault LU
- supervisor
- organization
- course
- FYSK02 20212
- year
- 2022
- type
- M2 - Bachelor Degree
- subject
- keywords
- Glaciers, Glaciology, Svalbard, Geophysics, Superimposed Ice, Foxfonna, Geology.
- language
- English
- id
- 9076352
- date added to LUP
- 2022-04-06 15:52:10
- date last changed
- 2022-04-06 15:52:10
@misc{9076352,
abstract = {{The processes of meltwater storage in firn and the impact of refreezing on firn-coveredglaciers have been investigated on the Greenland ice-sheet. On Svalbard, climate changepromotes the disappearance of firn on glaciers. This thesis project aims to monitor theheat exchanges between the snowpack and the ice surface on a non firn-covered glacier,on Foxfonna, Spitzbergen, Svalbard, and to draw the picture of the events occurring inthe snowpack over a melting season, from May to July 2021.This report has two aims. First, to highlight the evolution of snow properties; bulk den-sity, heat flow,Snow Water Equivalent(SWE, amount of water that would result from themelting of 1m2surface area of that snowpack), and albedo, during melting, and attemptsto do so during the formation of superimposed ice, e.g. refreezing of meltwater on theglacier ice. Second, to model the snow melt using local weather data and to compare themodelled results with the observed melt, measured periodically throughout the fieldworkperiod. Snow pits were dug to measure the snow temperature and density, and to observethe evolution of the snowpack properties. In the snow pits, the focus was set on the snowmetamorphism, albedo, water content and stakes measurements. Finally, stakes measure-ments were realized to assess the growth of superimposed ice.The weather data indicates a sudden warming on the 2ndof June, which rendered thesnowpack isothermal (0°C over the entire column), as observed from the snow temper-ature. The already established melt became stronger as a result of this warm event, asobserved in the snow depth data. The snow melt modelled from the 6thto the 11thofJune indicates results diverging from the actual snow melt by 95%. Nonetheless, themodel describes the main physics of the system, as it predicts that melting must occur, asexpected. The divergence between the modelled and the observed melt can be attributedto the use of weather stations located away from the site. As snow melted, the bulkdensity increased, resulting in a stronger heat flow within the snowpack over time. Theinter-comparison of the SWE and the bulk density can reveal that snow metamorphismoccurred, or that snow has accumulated on the glacier. Such inter-comparison was suc-cessfully carried out at the beginning of the fieldwork, revealing the accumulation of snowby some wind, in accordance with the snow depth and albedo data. Besides this one event,the SWE data did not reveal any clear trend over time, perhaps because of the interplaybetween the progressive melt, which should make it decrease, and the advection of waterfrom up-glacier snow, which would make the SWE increase. Likely the location of the gridin a bowl prevented the analyses of the SWE data. Finally, the formation of superimposedice was detected at the very end of the fieldwork. Its formation has been prevented bythe fact that snowpack became suddenly isothermal by this warm event. With the coldcontent of the snowpack being entirely removed, not much refreezing occurred.}},
author = {{Desjonquères, Thibault}},
language = {{eng}},
note = {{Student Paper}},
title = {{Monitoring of heat exchanges in thesnowpack of Foxfonna glacier, Spitzbergen,Svalbard.}},
year = {{2022}},
}