Regional climate models (RCMs), as applied within the HighNoon project, use glacier areas and glacier volumes in combination with mass and energy balance models and therefore allow a dynamical coupling of glaciers with the climate. To provide the required glacier data to the climate modelers, UNIGE collected glacier outlines from various databases and compiled a comprehensive inventory of the best available glacier data for the entire HighNoon modeling domain. For certain regions in the western Himalayas that have not been covered by the global glacier databases until today, new outlines were created by remote sensing techniques. In some parts of the Himalayas, however, the data quality remains poor and is associated with larger uncertainties. Glacier areas were aggregated per gridbox of the REMO RCM and delivered to MPI (figure below).
Currently, glacier volumes are estimated by applying different methods, such as ice-thickness modeling, slope dependent thickness estimations, and volume-area scaling. Related uncertainties are estimated by combining the different volume-estimation approaches. The topographic glacier parameters required for some of these methods were determined by fusing the collected glacier outlines with the SRTM DEM and the ASTER GDEM. First results are consistent with findings from previous studies, but the uncertainties are estimated to be about ±30% due to the quality of the input data as well as methodological issues.
Source: UNIGE, August 29, 2011