If you live in a very cold area, you may have seen the depth of a bank of snow shrink even though temperatures remain below the melting point of water. how might you account for this observation?

To answer the question above, if the day sky is clear it collects radiation. If air is dry snow sublimates faster. If both cases overlap it disappears faster where ever coldest. Thank you for posting your question here. I hope my answer helps. 

Magma  is composed of molten rock and is  stored  in the earth's crust. lava is  magma  that reaches the surface of our planet through a volcano vent.