Mass balance glaciers
The mass balance of certain glaciers is measured in the field by obtaining data in the spring and autumn. This data is used to calculate the winter balance (accumulation) and summer balance (melting), which are then added together to produce the net balance, the annual state of health of the glacier between two consecutive autumn measurements. The mass balance primarily depends on precipitation in the winter and temperature in the summer, but calving and marine melting are also important for some glaciers which terminate in the sea.
Mass balance is measured in the field for only a few glaciers in Svalbard, which are located almost exclusively along the west coast of Spitsbergen. The Norwegian Polar Institute is currently measuring the mass balance of four glaciers in the Kongsfjord area: Austre Brøggerbreen (since 1967), Midtre Lovénbreen (since 1968), Kongsvegen (since 1987) and Kronebreen/Holtedahlfonna (since 2003).
The Norwegian Polar Institute and the University of Oslo are cooperating concerning the taking of mass balance measurements on Etonbreen, an arm of Austfonna. Austfonna is the largest ice cap in Svalbard and has been monitored using a weather station and annual mass balance measurements since 2004. Extensive, gently sloping formations and relatively easy access make Austfonna ideal for the calibration and validation of satellite data and climate models with relevance to the larger ice masses of Greenland and Antarctica. As part of the CryoVEX programme of the European Space Agency (ESA), regular programmes have been carried out using coordinated aerial and ground-based readings for comparison with satellite data. The mass balances from Etonbreen on Austfonna form part of the climate monitoring being carried out under MOSJ with annual updates.