Wednesday, March 04, 2009

Winter: What makes it cold out?

<<< CAUTION: SCIENCE AHEAD >>>
Ok, this is gonna sound strange, but I'm not buying the whole explanation of what makes winter cold. Yep, this is explained in probably 4th grade science, but I've been thinking about it lately and I'm just not buying it.
Ok, first the myth...
Some people believe that winter is caused when the earth is further away from the sun. Bzzz. Wrong. In actuality, The earth is closer (only by a little relatively speaking) during the (northern hemisphere's) winter months.
So the next logical question... then why is it always colder in the winter time?
The answer, is due to the earth's tilt. The Earth is tilted 23.44 degrees. Also called the "Axial Tilt" (wikipedia here). And yes, there is a slight wobble, but we won't get into that now.
So, When we are in the summer months, the earth's top (north) is tilted towards the sun, which means it will have MORE sunlight during the daytime, and thus be warmer. Vice Versa, in the southern hemisphere, the earth is tilted away from the sun, so it has shorter days, and less sunlight - thus colder.
Summer and Winter also has to do with the angle of the sunlight hitting the earth too. During the winter, the light hits the earth at a larger angle, whereas in the summer it hits it more face on or directly. You can see some charts and illustrations on this wiki page here.
Ok, I understand all that.
But here's what I don't quite get...
Why the "extreme" temperature shifts from day to day? So for the most part, the temps can be averaged out to lets say "10-15 degrees" (I'm guesstimating). In other words, one day it might be 35º the next it could be 42º or even 28º (a 15º difference).
But as an example here, last weekend (Sat) it was around 50 degrees. I had to crack my window to get some fresh air as I was driving. Then on Sunday night, we got hit with about 8-10 inches of snow, and the temps were in the low 20's! That's a 30º difference in a matter of a day or so!
Our earth's axis sure didn't change during that time! So what caused that temp shift so drastically? To top it off, This coming Saturday, we're supposed to be back up into the 60's!
So, I want to know why or what causes these temperature shifts?
Is it simply the wind patterns? The Jet Stream? A passing rain storm/snow storm? What kind of wind pattern can shift a patch of cold air that far from the north down to the south in a matter of a few hours? Wouldn't you think it would be a fierce windstorm?
Also...
It seems the more drastic temp changes are around spring and fall, ie: if it's summer time, and a 95º day, chances are that the next day will be around 95º too, and not 75º. So why is it more windy (if that's the answer) during the spring and fall?
If anyone can point to a 4th grader who knows this answer, please do. OR better yet a web link that expains this, I'd appreciate it :)
(I tried googling it briefly, but most of the hits came up with temperature shifts due to global warming.) I'm talking about Temp shifts from day to day.

2 comments:

veronica said...

ya know... my daughter and i were just talking about this the other day.. i'll have to read her your post.

:)

Totl said...

"But as an example here, last weekend (Sat) it was around 50 degrees. I had to crack my window to get some fresh air as I was driving. Then on Sunday night, we got hit with about 8-10 inches of snow, and the temps were in the low 20's! That's a 30º difference in a matter of a day or so!
Our earth's axis sure didn't change during that time! So what caused that temp shift so drastically?"

Hello. Im going to take a stab at this. However I do not have your location weather tables or any information about where you are but this is great news. The reason that this is great news is this will make perfect sense to you. Here is what causes such a drastic change in the weather on those praticular days. First you explained it was a relativity fair tempurature like 50 degrees out side even had to crack the window. However if it would have been below 32 degrees you would have not noticed this and this is why. The hotter the day the colder the night is going to be when the axis tilt is further away from the sun. Follow this durring the day the sun warms the earth. Water from the earth heats and warms and forms into little tiny water particles. These particles bind together in billions to form fog. This fog mixes with air or wind to form what we call clouds. Due to the earth axis being further away from the sun in the winter time when we revolve facing away from the sun there is not enough heat from the sun to keep the particles mist. These particles begain to freeze very quickly and thus form snow over night and tempurtures drop quickly as the sun rises in the morning the wind tempuratures increase and a great morning cold rolls thru the valleys. I hope that answers your question. this is true any where you live at some point at some time this is how its formed