Experimental Studies on the Relation between the Rate of Sublimation and Intensity of Irradiated Radiation on Snow Surface

Abstract

The experiments on the relation between the rate of sublimation from snow surface and intensity of irradiated radiation or wind velocity to the snow surface are carrid out in the low temperature room that a uniform air temperature and a uniform humidity is keeped up respectively -15°C and 5457%, and by using snow that snow density and the diameter of a granule of snow is respectively 0. 390.41 (g/cm3) and below 0.42mm.In the text, the experimental apparatus of the low temperature room is shown in Fig. 1, and the snow vessel of sublimation is shown in Fig. 2.As the radiation source, the Yoko Electric Light were used, and the radiation and the solar radiation are distributed by the same energy quantity from short to long-wave radiation.Results of experiments : (1) The rate of subrimation increase quickly with the intensity of irradiated radiation. In Fig. 4 of text, it is shown by solid curve based on the open circle*, and it is given by E= (4e-3.828R +20R+2.7U-2.5) ×10-7… (1) when U>0.5 (m/s), where E (g/cm2sec), U (m/s) and R (cal/cm2min) are respectively the rate of subrimation, the wind velocity and the intensity of irradiated radiation.(2) The rate of sublimation with radiation ER are found to be not concerned with wind velocity (Let it be assumed that the rate of sublimation is the sum of the both of the rate of sublimation with wind velocity EW and radiation ER). In Fig. 6 of the text, it is shown by the open curcle*, and it is given by ER= (e-3.828R + 5R-1) ·4 × 10-7 … (2) (3) The ratio of LER to R (1-r), η are shown by percentage in Fig. 7 of the test, whore L and r are respectively the latent heat of sublimation and albedo of snow surface. η is calculated by assuming r=0.7 for the value of albedo.* The soled circle and the open square in Fig. 4 and 6 are the values masured by radiation of colour photo-light and heater of nicrom wire respectively.