Bulk volumetric liquid water content in a seasonal snowpack: modeling its dynamics in different climatic conditions. (December 2015) - Avanzi, Francesco
Highlights: We model the bulk volumetric liquid water content in snow using a simple model. We evaluate model performances using data from three sites in Japan. We evaluate the performances of a coupled melt–freeze degree–hour approach. The estimations of average volumetric liquid water content agree with data. The model correctly predict approximate wetness conditions in a non-calibration site. Abstract: We focus on the dynamics of volumetric liquid water content in seasonal snow covers. This is a key variable describing the fate of snowpacks during the melting season. However, its measurement and/or prediction by means of models at high spatial and temporal resolutions is still difficult due to both practical and theoretical reasons. To overcome these limitations in operational applications, we test the capability of a one-dimensional model to predict the dynamics of bulk volumetric liquid water content during a snow season. Multi-year data collected in three experimental sites in Japan are used as an evaluation. These sites are subjected to different climatic conditions. The model requires the calibration of one or two parameters, according to the degree of detail used. Either a simple temperature-index or a coupled melt–freeze temperature-index approach are considered to predict melting and/or melt–freeze dynamics of liquid water. Results show that, if melt–freeze dynamics are modeled, median absolute differences between data and predictions are consistently lower than 1 vol% at the sites where data of liquid water content are available. In addition, we find also that the model predicts correctly a dry condition in 80% of the observed cases at a site where calibration data are scarce. At the same site, observed isothermal conditions of the snow cover at 0 °C correspond to predictions of bulk volumetric liquid water content that are greater than 0.