Distributed modelling of melting on Antizana Glacier 15, Ecuador
Abstract
The surface energy balance of Ecuador's glaciers is particularly sensitive to their surface albedo whose variations are closely linked to solid precipitation occurrence. In order to assess distributed albedo values at the glacier scale, an automatic digital camera was installed on the frontal moraine of Antizana Glacier 15. The images from this camera were processed to obtain the relative variation of albedo. Over the period March 15, 2002 April 1, 2003, a distributed surface energy balance model was applied using as input the meteorological dataset recollected locally at the glacier surface and the albedo maps. Despite the restricted number of good quality photographs due to the important cloudiness at the study site, the model allows accurate computations of the monthly ablation and of the annual specific mass balance. Simulations show that gradients of ablation with altitude are mostly explained by albedo variations. Over the ablation area the computed ablation agrees fairly well with the field measurements. However, in the accumulation area, computed turbulent heat fluxes are overestimated and are responsible for a large difference between computed and observed ablation. Finally the model is simplified to a 1-D model taking into account only the albedo and temperature lapse rate with altitude. This operational model is successfully tested over the 1995-2005 period.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.C33C1302W
- Keywords:
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- 0720 Glaciers;
- 0764 Energy balance;
- 0798 Modeling;
- 1827 Glaciology (0736;
- 0776;
- 1863);
- 1895 Instruments and techniques: monitoring