关键词: 粒雪层;热学性质;活动层温度;活动层(季节变化层)

Abstract:

Based on detailed data on density and temperature in a shallow (about 20m deep) borehole at 1043m a.s.l.on the Law Dome Ice Cap, Antarctica, thermal properties and temperature distribution of snow/ firn in the active layer are discussed. Refering to the review of works on thermal properties of snow by Yen (1981), we suggest that the relationship between thermal conductivity (λ) and density (ρ) may be expressed by a formula, λ= 0.0784+2.697 ρ2. Then the heat transfer equation in an ununifrom medium, i.e.with variable thermal parameters, is applied and solved analytically by two approaches, laminar structure and vertical movement models.Comparison of calculated and measured temeratures indicates that the first model is bettr to describe the actual temperature distribution in snow / firn layer on a glacier, but the latter is more convenient to use because of its simplicity .The difference between calculated and measured temperatures is mainly due to the determination of boundary conditions.