| MadSci Network: Physics |
What can happen is that the ultraviolet (UV) sunlight passes through the thin layer of ice/snow and heats the ground or whatever underneath and is absorbed. The ground (or concrete say) releases some of the light as infrared (IR) or heat. For thicker layers of snow/ice the sunlight is reflected back almost entirely as visible and UV light and has no melting effect. This is the same effect that makes beach sand or black-top hot in the summer. On overcast days, the UV light that reaches the surface of the earth is greatly reduced by the clouds which scatter much of the UV back into space. Sincerely, Tom "Get Me a Tan" Cull
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