In years of heavy snow pack in the mountains it is sometimes desirable to induce
ID: 1532191 • Letter: I
Question
In years of heavy snow pack in the mountains it is sometimes desirable to induce early melting of the snow, rather than wait until it all melts suddenly and causes floods. It has been suggested that a way to accomplish this might be to have planes fly over the snow fields and sprinkle them with black soot. What do you think of this idea? Would it work?
a. No, it would not work because sunlight has very little effect on how fast the snow melts. b. Yes, it would work because the soot would decrease the specific heat capacity of the snow. c. Yes, it would probably work because the black surface would be a better absorber of sunlight than would the white snow. d. No, it would not work because it is infrared radiation and not visible radiation which melts the snow. e. Yes, it would work because the soot would raise the melting point of the snow.Explanation / Answer
Soot is impure form of carbon which appear black in colour. If black soot is sprinkled over vast masses of snow, the white colour of ice is darkened by the layers formed by soot.
The major reason that ice covered areas are cold, is that, white colour is a good reflector of sunlight and hence does not absorb the heat. When this ice is covered with black coloured soot, it starts absorbing solar heat, as black colour is a good absorber of heat and causes the snow to melt faster.
So, (C) Yes, it would probably work because the black surface would be a better absorber of sunlight than would the white snow.