Question

Why does not all the now all the snow on the mountains melt to water after winter is over?

Answer 1

Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when snow does melt, it is not because of the sunlight. Snow does not melt on a spring day because of the sun’s heat. It melts because of the warm air from the sea.

After snow becomes ice, a different problem arises. Clean ice absorbs about two-thirds of the sunlight that hits it - but ice is transparent enough for the light to penetrate quite a long way (10 metres or more) before the absorption takes place.

And snow on mountains does not melt all at once because every kilogram of snow requires 33600 J of heat energy in order to form water at 0 degree celcius.