The thermal structure of the Recovery Glacier drainage basin, Antarctica, derived from three-dimensional numerical flow modelling
The basal conditions of the ice sheet are of crucial importance for the dynamics of the ice, as they determine the sliding at the ice base. Since the base is hardly accessible for in situ observations, indirect measurements of the basal properties are of great interest. The bed reflectivity derived...
| Main Authors: | , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2015
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/42743/ https://www.igsoc.org/symposia/2015/cambridge/proceedings/proceedings.html https://hdl.handle.net/10013/epic.49350 |
| Summary: | The basal conditions of the ice sheet are of crucial importance for the dynamics of the ice, as they determine the sliding at the ice base. Since the base is hardly accessible for in situ observations, indirect measurements of the basal properties are of great interest. The bed reflectivity derived from the radar-measured bed returned power (BRP) has been widely used to distinguish between wet and dry basal areas of a glacier. As the BRP depends on the loss due to englacial dielectric attenuation, which itself is primarily a function of ice temperature, the vertical thermal structure within the ice must be known along the radar profiles. In January 2014 an airborne radio-echo sounding campaign of the Alfred Wegener Institute was carried out in the Recovery Glacier drainage area. The newly derived ice thickness measurements have been incorporated into the Bedmap2 datasets for ice thickness and bedrock elevation replacing data in the so far unmapped area. In addition to the original Bedmap2 geometry this new geometry is used for numerical ice flow simulations using the Parallel Ice Sheet Model (PISM). Simulations are carried out across a broad range of datasets for present-day boundary conditions for the Antarctic ice sheet. Here we present our analysis of the thermal structure of the Antarctic ice sheet based on the model results with a strong focus on the Recovery Glacier area. We compare our results with simplified 1-D vertical heat transport assumptions and discuss the implications for radar bed returned power estimates. |
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