Quote:
Originally Posted by Drewski Canuck
Seen Pinehurst iced up a few May Long weekends now.
Until you get rid of the snow pack on the ice, the sun does not penetrate to the lake bottom to get the heat starting underneath in the shallows.
Rain can sure help, but it takes alot of rain to cause a phase change. I understand it is 84 joules of energy to take a cubic centimeter of ice to liquid state.
Drewski
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Heat is transferable from all sources. So, as the ground heats up, it transfers at least a portion of it to the lake. The only perfect insulator is a vacuum.
It takes 1 calorie to heat 1g of water 1C. There are 4.2 joules/calorie. Conservation of energy works both ways, so cooling 1 mL of water from 10C (the average temperature of a spring shower) to 0C (the temperature of ice at phase change) will transfer 42 joules of heat energy.
We need to take into account that ice is less dense than water. So 1g of water is 1 cm^3 or 1 mL. 1cm^3 of ice is 0.9g
if you want to do all the ratios, it takes approximately 7mL of water at 10C to change 1mL of ice into water. since heat is being transferred from all directions. The ice itself is not an infinite heat sink. The water underneath the ice will be at 4C and the air temperature will be above zero, it thusly will take less than 7ml of 10C rainwater to change 1g of ice into pike fishing time!!