1:45 PM - 3:15 PM
[O08-P92] Simple Snow Reproduction Experiment using a Freezer and Comparison with Natural Snow
Keywords:Artificial snow experiment equipment , Snow crystal , Yellowknife
1 Research Background and Purpose
Understanding snow crystals can be linked to understanding the upper atmosphere and weather, which can lead to improved weather forecasting. There are two approaches to understand snow crystals; observation and reproduction. As the former study, in the Kanto Snow Project, Araki(2018) investigated the relationship between the atmosphere and snow by collecting photographs of snow from people living in the Kanto region and connecting the snow crystals with the weather conditions of the day.
As a reproduction experiment, a rabbit hair was dropped in a very low temperature room, and a snow crystal was reproduced by exposing it to water vapor evaporated from a dish(Nakaya1954). This kind of study, reproducing snow, is difficult to conduct because it requires large and expensive equipment.
In addition, as an inexpensive and possible way to reproduce snow, there is a method of reproducing snow crystals using dried ice and kite strings, but there are some problems. For example, temperature control is difficult because dry ice is used, and there is a limit to types of the snow crystals that can be reproduced. Another problem is that snow crystals reproduced in this experiment are different from natural snow because kite strings are used for condensation nuclei.
Based on these, the purpose of this study was to develop a device that can reproduce various snow crystals without much difference in price from conventional devices.
2 Research method
Experiment1: Observation and Discussion of Snow Crystals with a Yellowknife from October 23-26, 2023, in a suburb of Yellowknife, Canada, snow was dropped on aluminum foil cooled to ambient temperature, observed and photographed with a hand-herd microscope, and photographs were classified according to the classification of the Kanto Snow Cystal Project. Based on these photographs, atmospheric conditions during the observation period were predicted, and the accuracy of the prediction was confirmed by comparing with actual data. When the type and shape of snow were examined, it was found that the approximate atmospheric temperature in the sky can be predicted from the shape of snow crystals. However, it was not possible to obtain detailed data on the amount of water vapor in the atmosphere over Yellowknife at the time, so the projection couldn’t be compared with the actual data.
Experiment2: Development and Study of an Artificial Snow Generator
A plastic ball with a hollow was put inside in a freezer set at a temperature of -20C, and smoke from the incense stick as a condensation nuclei was put into a freezer. A heat-resistant rubber tube was connected to a round-bottomed flask containing water, and sent water vapor was sent through it. It was intended that ice crystals would be formed in the condensation nuclei by convective flow within the plastic hemisphere using the momentum and temperature gradient of water vapor. The amount of water vapor was adjusted by changing the temperature of the water, and although some snow-like ice crystals were successfully identified, most of the ice crystals were formed on the walls of the plastic hemisphere, not in the fumes of incense put as the condensation nuclei.
3 Result and Discussion
Natural snow could be divided into certain categories with variations in the amount of moisture. On the other hand, in the case of artificial snow, even thought it was made under the same conditions, there were cases where it could not be classified into a certain type.
However, it was confirmed that the formation of ice crystals was related to temperature and the amount of water vapor in both artificial snow and natural snow. The reason why specific snow ice crystals did not form in the reproduction experiment of this study is that snow crystals are formed in micro ice and water droplet inside the clouds, and the nm-sized smoke of incense sticks could be too small.
Understanding snow crystals can be linked to understanding the upper atmosphere and weather, which can lead to improved weather forecasting. There are two approaches to understand snow crystals; observation and reproduction. As the former study, in the Kanto Snow Project, Araki(2018) investigated the relationship between the atmosphere and snow by collecting photographs of snow from people living in the Kanto region and connecting the snow crystals with the weather conditions of the day.
As a reproduction experiment, a rabbit hair was dropped in a very low temperature room, and a snow crystal was reproduced by exposing it to water vapor evaporated from a dish(Nakaya1954). This kind of study, reproducing snow, is difficult to conduct because it requires large and expensive equipment.
In addition, as an inexpensive and possible way to reproduce snow, there is a method of reproducing snow crystals using dried ice and kite strings, but there are some problems. For example, temperature control is difficult because dry ice is used, and there is a limit to types of the snow crystals that can be reproduced. Another problem is that snow crystals reproduced in this experiment are different from natural snow because kite strings are used for condensation nuclei.
Based on these, the purpose of this study was to develop a device that can reproduce various snow crystals without much difference in price from conventional devices.
2 Research method
Experiment1: Observation and Discussion of Snow Crystals with a Yellowknife from October 23-26, 2023, in a suburb of Yellowknife, Canada, snow was dropped on aluminum foil cooled to ambient temperature, observed and photographed with a hand-herd microscope, and photographs were classified according to the classification of the Kanto Snow Cystal Project. Based on these photographs, atmospheric conditions during the observation period were predicted, and the accuracy of the prediction was confirmed by comparing with actual data. When the type and shape of snow were examined, it was found that the approximate atmospheric temperature in the sky can be predicted from the shape of snow crystals. However, it was not possible to obtain detailed data on the amount of water vapor in the atmosphere over Yellowknife at the time, so the projection couldn’t be compared with the actual data.
Experiment2: Development and Study of an Artificial Snow Generator
A plastic ball with a hollow was put inside in a freezer set at a temperature of -20C, and smoke from the incense stick as a condensation nuclei was put into a freezer. A heat-resistant rubber tube was connected to a round-bottomed flask containing water, and sent water vapor was sent through it. It was intended that ice crystals would be formed in the condensation nuclei by convective flow within the plastic hemisphere using the momentum and temperature gradient of water vapor. The amount of water vapor was adjusted by changing the temperature of the water, and although some snow-like ice crystals were successfully identified, most of the ice crystals were formed on the walls of the plastic hemisphere, not in the fumes of incense put as the condensation nuclei.
3 Result and Discussion
Natural snow could be divided into certain categories with variations in the amount of moisture. On the other hand, in the case of artificial snow, even thought it was made under the same conditions, there were cases where it could not be classified into a certain type.
However, it was confirmed that the formation of ice crystals was related to temperature and the amount of water vapor in both artificial snow and natural snow. The reason why specific snow ice crystals did not form in the reproduction experiment of this study is that snow crystals are formed in micro ice and water droplet inside the clouds, and the nm-sized smoke of incense sticks could be too small.