太阳辐射和地温对冰盖下水温的影响

太阳辐射可以透射穿过雪盖和冰盖与地温一起影响冰下水温的变化，加剧冰盖底部的融解和冲蚀，使得冰盖更易于崩溃开河。基于现有理论和原型观测研究成果，建立了描述太阳辐射在雪盖、冰盖和水体中的透射和吸收规律的数学模型；利用观测数据回归分析的方法，提出了太阳辐射可见光在水体中消光系数的参数化模型；然后研究了冰下水温的变化与太阳辐射和地温的函数关系。研究证实，冰下水温随太阳净辐射和地温的增加而升高，随雪厚和冰厚的增加而下降，并且与水体与冰盖的热交换系数成反比。此外，太阳辐射的透射可能使得开河期冰盖糙率不是减小，而是增大。

Effects of solar radiation and ground temperature on water temperature under ice cover

Solar radiation can penetrate snow sheet and ice cover, together with the ground temperature, affect the change of water temperature under the ice, aggravating the melting and erosion on the bottom of the ice cover, and making the ice cover more prone to collapse and break-up. Based on the existing theory and prototype observation research results, mathematical models describing the transmission and absorption of solar radiation in snow cover, ice cover and water are established; using the method of regression analysis of observation data, a parametric model of extinction coefficient of solar radiation visible light in water is proposed; then, the functional relationship between the variation of subglacial water temperature and solar radiation and ground temperature is studied. The results show that the subglacial water temperature increases with the increase of solar net radiation and ground temperature, decreases with the increase of snow thickness and ice thickness, and is inversely proportional to the heat exchange coefficient between water body and ice cover. In addition, the transmission of solar radiation may make the roughness of ice cover not decrease, but increase.