Application of a minimal model to Kongsvegen and Kronebreen

Abstract

The long-term behaviour of the Kongsvegen-Kronebreen system is studied with a minimal glacier model, based on heavily parameterized representations of the surface mass balance and calving flux. Kongsvegen is about 27 km long, surging glacier, coupled to the larger calving glacier Kronebreen of about 50 km. The model is driven by a climate reconstruction from 1300 AD onwards, based on ice-core data from Lomonosovfonna and climate records from Longyearbyen. The model is calibrated to match the systems observed length in 1936, before Kongsvegens last surge occurred. We find that the climate variations are not able to produce the retreat observed after the surge, and conclude that an increased calving flux accounts for the observed retreat. If climatic conditions will remain as they were for the period 1990-2007, Kronebreen will reach a steady state around 2160, after it has lost 21% of its volume in 2005. For the RCP8.5 scenario by the IPCC, the equilibrium line will rise with 1.16 m yr -1, resulting in an accelerated volume loss resulting in 41% loss in the year 2200 compared to 2005, and ultimately the glacier disappears several hundreds of years later.