Numerical modeling of Glacier d'Argentiere and its historic front variations
A numerical glacier model has been developed for Glacier d'Argentiere (France) in order to study its relation with climate and investigate possible causes forthe observed variations in the terminus record since the beginning of the Little Ice Age. At first results are presented from a basic sensitivity investigation,with plots of steady state glacier length versus perturbations in mass balance and glacier reaction with respect to sinusoidal net balance oscillations. An attemptis then made to simulate the historic front variations. The mass balance history of the glacier is constructed assuming a linear relationship with (i) summertemperature anomalies and (ii) mean annual temperature anomalies for Basel dating back to the beginning of the 16th century. Although model run (ii) turnsout to yield better agreement with the observations, both simulations have in common that the observed glacier retreat comes too late. Improved simulationscan only be obtained assuming an additional negative mass balance perturbation of around 0.1 m/year over roughly the last 150 years. These results indicatethat the assumption of a linear relationship between summer temperature and the glacier's mass balance may not be valid anymore when extrapolated to pastenvironments. This might be evidence of additional micrometeorological and glacier surface conditions prevailing in valleys at maximum glacier extent, thatare not absorbed well in the climatic records.