A one dimensional model has been developed to simulate all-around snow metamorphism using meteorological data. This model takes into account the heat balance at snow surface and the heat conduction in snow as well as the liquid water flow and the densification, and calculates time series of profiles of temperature, liquid water content, snow density and solid impurities density. Improvements were made on parameterization of the compactive viscosity coefficient of wet snow and the thermal conductivity. Albedo decrease by impurities and liquid water in snow was considered for albedo parameterization.

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An inspection of the snow metamorphism model (Yamazaki et al. 1991) was performed. Calculated diurnal variation patterns of profiles of snow temperature, water content and other components were in agreement with observations at Zao Bodaira, Yamagata prefecture. Moreover, snow metamorphism was simulated for 90 days with the meteorological data and snow pit observations at the Institute of Low Temperature Science, Hokkaido university, and the meteorological data at Sapporo District Meteorological Observatory. It was found that the model was able to simulate long period variations of albedo, snow depth, snow water-equivalent and snow density profile.

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According to Sato (1990), sublimation rates were studied both theoretically and experimentally for the collected blowing snow in a net type collector.
Calculations based on the heat balance of the collected snow were made to examine the dependency of the sublimation rate on the following parameters: temperature and relative humidity of the air, and transfer coefficient for sensible heat, which is close to that for water vapor. The dependences are analogous to the case of a Cyclone type collector shown in Sato (1990).
From the measurements of sublimation rates in a cold room, it was found that the error in the mass flux measurment with the net type collector, caused by the sublimation of the collected blowing snow, is under that for the Cyclone type collector.
The transfer coefficient for sensible heat (water vapor) was evaluated from the measured sublimation rates. The transfer coefficient increases with the length of collected snow and with the decrease in its density. The transfer coefficient is directly proportional to the ambient wind speed.
As a result of this study charts were presented to give the sublimation rate under various meteorological conditions (air temperature, humidity, and wind speed).

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Rime, a kind of icing, on trees on high mountains, is widely known as a beautiful creation of nature in winter. However, because the climatic conditions necessary to produce icing are not so frequently satisfied, the incidence of such icing is limited to the western regions of Japan, like Mt. Unzen in Nagasaki prefecture, famous for rime.
The present study was conducted to make it possible to see indoor artifical icing throughout the year. In this study cooled wet air at temperatures of -5 and -10°C at a wind velocity of 5, 10 and 15 m/s was forced to flow through an acrylic resin pipe of 30 mm diameter in which a needle and a small wooden stick were mounted as bases for the icing to grow on. Mists from an ultrasonic humidifier were used to wet the cooled air. Using these facilities the relations between the test conditions and the characteristics of icing produced were investigated.
Various types of icing, hard rime, soft rime, glaze and air hoar were produced artificially by controlling the test conditions. The shapes and the growth speed of icing changed with the test conditions and some of the relations between them were clarified. The catch ratio in the present experiment was remarkably low in comparison with other researchers' data.

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[in Japanese]

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