Glaciodyn (Canada) IPY Project: Weather station data collected on the Belcher Glacier, Devon Island Ice Cap, 2008-2009
Field measurements were necessary to initialize, force, and validate the surface energy balance model for the Belcher Glacier. Hourly and daily averages of air temperature, relative humidity, wind speed and direction, net radiation, and surface elevation were recorded over the 2008 summer (June-Sept...
| Main Authors: | , , , |
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| Format: | Dataset |
| Language: | English |
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Canadian Cryospheric Information Network
2011
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.5443/10933 https://www.polardata.ca/pdcsearch/?doi_id=10933 |
| Summary: | Field measurements were necessary to initialize, force, and validate the surface energy balance model for the Belcher Glacier. Hourly and daily averages of air temperature, relative humidity, wind speed and direction, net radiation, and surface elevation were recorded over the 2008 summer (June-September) by two automatic weather stations (AWS) on the glacier centerline at elevations of 500 m and 900 m. All instruments were installed 2 m above the surface. In August 2009, the AWSs were re-programmed to record bi-hourly and daily averages of all meteorological variables to preserve battery power and memory. The AWSs are serviced annually. A total of 25 ablation stakes were drilled into the ice in May 2008 at 100 m elevation intervals between 500 m and 1100 m, and also at 250 m spacing on lateral transects at 500 m and 900 m elevation. These stakes were surveyed weekly in the 2008 summer, and once again in the spring of 2009. Snow pits were dug twice weekly at 900 m elevation to record the temperature and density of distinct horizons within the snowpack. : Purpose: This project ultimately aimed to run a distributed surface energy balance model coupled with a sub-surface snow model to investigate spatial and temporal variations in surface melt water production on the Belcher Glacier. Detailed measurements of meteorological variables and snow surface properties were collected in the summer (June-September) of 2008 in order to initialize, force, and validate the model. The Belcher Glacier is a major outlet glacier of the Devon Island ice cap and accounts for approximately half of the iceberg calving loss from the ice cap (~15% of the total mass loss). This is a contribution to an International Polar Year (IPY) project, aiming to investigate the hypothesis that hydrologically driven changes in ice flow will increase the rate of mass loss by iceberg calving, and how these dynamics will respond to future climate warming. : Summary: In the summer of 2008 (June 2 to September 14), detailed measurements of meteorological conditions and glacier surface properties were conducted in the Belcher Glacier catchment (718 km2), Devon Island Ice Cap, Nunavut, Canada. These measurements were used to force and validate a distributed surface energy balance model to calculate the surface energy balance and ablation rates. Spatially-averaged total water equivalent (w.e.) ablation was 677 mm w.e. and estimated runoff was 3.9 x (10+8) m3. Net radiation was the main source of energy over the study period (87%), followed by the sensible heat flux. Net longwave radiation and the latent heat flux represented an overall energy loss from the surface. Modeled melt season duration lasted from June 17 to August 15, and the majority of ablation occurred in two main periods, from June 26 to July 18, and from July 27 to August 14. Snowfall and lower air temperatures limited ablation between these dates and after August 15. Periods of high ablation were associated with positive air temperatures and high net shortwave radiation receipts, linked to regional high pressure. Periods of minimum ablation occurred when receipts were reduced (e.g. following summer snowfall) and when air temperatures were negative, associated with tracking low pressure systems. The largest changes in both the net surface energy balance and ablation rates were linked to changes in surface albedo associated with snowpack removal and ice melt. |
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