Evaluation of predicted soil frost and snow metamorphism by means of WINTEX and LAPP data

Snow cover and soil frost are important conditions affecting atmospheric humidity, and temperature in high latitudes. The hydro-thermodynamic soil-vegetation scheme (HTSVS) among other processes considers soil frost and snow-metamorphism. Using observed meteorological data collected during the WINTEX and LAPP program for two stations i.e. Sodanklya (Finland) and Marsta (Finland), HTSVS is evaluated. HTSVS was initialized by observed snow and soil temperature. Observed short-wave downward radiation, air temperature, precipitation, wind, and pressure data as well as parameterized long-wave downward radiation were used to force HTSVS. The model was run from March 12 thru May 30, 1997. Sensitivity analysis was carried out by varying various parameters and using different parameterization of long wave downward radiation alternatively. In the first month, snow height was slightly underpredicated, while towards the end of the snow season the model tends to slightly overestimate snow height. The results show that the model is sensitive to the parameterization of long-wave downward radiation. The offline evaluation of the modified HTSVS by using WINTEX and LAPP is still ongoing. More stations will be evaluated to gain better insight to models deficits and for model improvement in the future.