Wednesday, January 16, 2008

Why doesn't the coldest day happen on the shortest day?











Have you ever wondered why the shortest day (winter solstice around December 21st) isn't usually the coldest day of the year? Techincally it's because of the latent heat release of the earth. But in order to understand how this works I want you to think of the atmosphere as a bank account. I know it sounds weird, but keep reading!

During the summer we are gaining more energy and heat from the sun than we're giving back out. In other words, we're adding money to our bank account. Once we have a nice little savings in the bank, winter rolls around. When the winter solstice arrives we're taking in only a little heat and giving off much more. So, our bank account starts running in the red.

It's not until the middle of January (almost a month after the solstice) that we begin to see things turn around. Nowadays we're still giving off more heat than we're getting in return...so we're still in the process of cooling. Once we reach the end of January the sun will get high enough in the sky to prevent us from operating in the red. From this point on, we'll begin that surplus that will take us straight into summer.

4 comments:

Anonymous said...

Very interesting! Thanks Eric!

tony said...

Eric, do u think loves park will get more than rockford, or less, since we are a bit north of rockford. Snow wise that is.

Cassi said...

Thanks Eric. That analogy worked really well for me.

Candice said...

That was really interesting. I'm always the one that wants to know when the warm up will begin! Bring on summer (ok, I know that's a little premature).