Förbättrade prognoser av massförlust från arktiska glaciärer genom optimering av rutiner för beräkning av återfrysning av smältvatten i firn

Tidsperiod: 2015-01-01 till 2018-12-31

Projektledare: Veijo Pohjola

Medarbetare: Regine Hock, Rickard Pettersson

Finansiär: Vetenskapsrådet

Bidragstyp: Projektbidrag

Budget: 3 550 000 SEK

There are several forms of uncertainties in the predictive modeling of glacial mass balance. One of these uncertainties is to what degree melt water will refreeze, advect latent heat into, and stay as a heat and a water storage in the porous firn packs in Arctic glaciers and ice fields. Our aim is to improve the knowledge of the processes active within the refreezing of water in firn, and deliver an improved parameterization scheme to be used in higher order models. We will collect atmospheric data from an automatic weather station, and monitor firn temperatures within a test plot on a high altitude snow field on Svalbard. We will further map a 3D distribution of ice lenses in the plot, and repeat the mapping in subsequent years. This will form input into a firn-hydrology and energy balance model utilized to find the best setting of the parameterization for the density increase and the latent heat advection emanating from the refreezing within the firn pack. We will test the new parameterization on test sites with other climatic characteristics, as well as on long time scale data sets using data from ice cores. We will use the atmospheric model WRF to downscale ERA data for input, and to test our refreezing schemes. Ultimately the improved schemes for refreezing will be included in higher order climate and earth system models.