Naked Science Forum

Life Sciences => The Environment => Topic started by: Gary Staab on 20/01/2009 09:10:25

Title: Why does it seem to get colder at sunrise?
Post by: Gary Staab on 20/01/2009 09:10:25

Gary Staab asked the Naked Scientists:
   
Why does it seem that the temperature drops just at sunrise? or is this just a matter of perception?

What do you think?

Title: Why does it seem to get colder at sunrise?
Post by: Chemistry4me on 20/01/2009 09:21:37

Quote from: Paul. on 17/01/2009 16:13:17

The daily lows are normally recorded around dawn, and the daily highs around two hours after midday.

So it is not a perception.

Title: Why does it seem to get colder at sunrise?
Post by: paul.fr on 20/01/2009 19:27:07

If you imagine that you have had a clear, cloud free night, then from the sun setting to rising the earth has been losing heat. So during the night the earth has been radiating heat and cooling down, the air at low levels has also been cooling. So the coldest part of the day should be that time which the earth has been losing more heat that it gained.

As stated above, the coldest part of the day is usually around dawn, or more accurately about an hour after dawn.

Title: Why does it seem to get colder at sunrise?
Post by: Karsten on 24/01/2009 17:37:12

Could the rising sun also cool you a bit more due to increased evaporation? The moment the sun shines whatever is wet will evaporate and cool whatever it sits on?