A One-dimensional Land Surface Model Adaptable to Intensely Cold Regions and its Applications in Eastern Siberia

抄録

A one-dimensional land surface model has been developed to estimate water and energy fluxes between the atmosphere and ground surfaces. The model includes three submodels; vegetation, snow cover, and soil. In order to adapt the model to intensely cold regions, the snow cover submodel can consider depth hoar by means of effective temperature gradient. This submodel can calculate profiles of snow temperature, density, and liquid water content using meteorological data inputs; the model structure is simple having snow layers with the same thickness. The ratio of fallen snow amount to rain amount is given as a function of wet-bulb temperature. The model has been applied to a GAME-Siberia site in the Central Yakutia, Russia. Since we do not have complete data sets in midwinter, the model has been validated through whole winter simulations at several routine stations first. Snow depth and snow-cover period are simulated reasonably. Next, fluxes have been estimated using 1998 data at the GAME plain taiga site, compared with the observed fluxes. Diurnal and seasonal changes of fluxes are simulated reasonably. The calculated snow cover disappearance date is earlier than the observed day.