Air temps, water temps, and radiational cooling

Merrymeeting · 10-21-2008, 09:34 AM

I've been tracking the nighttime temps VERY closely this week. Normally we close up our foundationless, unheated camp on Columbus Day weekend. But for many reasons were unable to finish this year and will be completing the job this weekend.

When I saw the forecast for some nights in the mid-20's this week, I began fretting about pipes freezing. But I consoled myself by reasoning that this cold would be short in duration, that the inside of the house would remain warmer from residual daytime heat (though several pipes are exposed underneath), and most importantly, the radiated heat from the lake would keep localized temps higher.

I am surprised to see the low recordings on the Black Cat Weather site. Despite being surrounded by water in the high-50's, the nighttime temps have still gone into the high 20's. Not what I would have expected with all that "heat" around it.

I know these clear, cool nights result in radiational cooling where the cold drops from above. But it is still surprising that it has such a dramatic effect so close to the water.

CLA, can you give us a lesson on the interaction between all these conflicting micro-layers during this season of change?

Thanks!

10-21-2008, 09:34 AM	#1
Merrymeeting Senior Member Join Date: Mar 2003 Location: Merrymeeting Lake, New Durham Posts: 2,224 Thanks: 302 Thanked 798 Times in 367 Posts	Air temps, water temps, and radiational cooling I've been tracking the nighttime temps VERY closely this week. Normally we close up our foundationless, unheated camp on Columbus Day weekend. But for many reasons were unable to finish this year and will be completing the job this weekend. When I saw the forecast for some nights in the mid-20's this week, I began fretting about pipes freezing. But I consoled myself by reasoning that this cold would be short in duration, that the inside of the house would remain warmer from residual daytime heat (though several pipes are exposed underneath), and most importantly, the radiated heat from the lake would keep localized temps higher. I am surprised to see the low recordings on the Black Cat Weather site. Despite being surrounded by water in the high-50's, the nighttime temps have still gone into the high 20's. Not what I would have expected with all that "heat" around it. I know these clear, cool nights result in radiational cooling where the cold drops from above. But it is still surprising that it has such a dramatic effect so close to the water. CLA, can you give us a lesson on the interaction between all these conflicting micro-layers during this season of change? Thanks!