Surface energy balance of seasonal snow cover for snow-melt estimation in N–W Himalaya

[摘要] This study describes time series analysis of snow-melt,radiation data and energy balance for a seasonal snow cover at Dhundi field station of SASE,which lies in Pir Panjal range of the N –W Himalaya,for a winter season from 13 January to 12 April 2005.The analysis shows that mean snow surface temperature remains very close to the melting temperature of snow.It was found close to -1°C for the complete observational period which makes the snow pack at Dhundi moist from its beginning.The average air temperature over this period was found to be 3.5°C with hourly average variation from -5.5°C to 13°C. The snow surface at this station received a mean short wave radiation of 430 W m−2, out of which 298 W m−2 was re flected back by the snow surface with mean albedo value of 0.70. The high average temperature and more absorption of solar radiation resulted in higher thermal state of the snowpack which was further responsible for faster and higher densification of the snowpack. Net radiation energy was the major component of surface energy budget with a mean value of 83 W m−2. Bulk transfer model was used to calculate turbulent fluxes. The net energy was utilized for satisfying cold content and snow-melt by using measured snow surface temperature and density of snow pack. The mean square error between calculated and measured daily snow-melt was found to be approximately 6.6 mm of water equivalent.

[学科分类] 天文学(综合)

[关键词] Surface energy balance;turbulent flux;radiation energy;snow-melt;data analysis;hydrology;modeling.