mawingho
Topic Author
Posts: 41
Joined: Sun Jul 22, 2012 4:23 pm

Meteorology Prevailing Wind

Tue Aug 28, 2012 5:18 pm

"Air flow from high-pressure area to a low-pressure area, but other effects resulting from the rotation of the earth modify its direction of flow. The result is that air flows anticlockwise around high-pressure area and clockwise around low-pressure areas in the southern hemisphere. (The direction of flow is reversed in the northern hemisphere.)"

I asked someone a question related to the above sentence, and he said the wind flow from north pole to equator while the earth is rotating.

If this is true, then the air flow should be clockwise in southern hemisphere since the air flow from H to L.

I also see this page in my book, http://www.scidacreview.org/0701/images/climate2.jpg

I don't know why the direction of prevailing wind is flow like this (many arrows on the earth with different directions in different layers)

I hope someone can help me out.

Thank you very much in advance.
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Meteorology Prevailing Wind

Tue Aug 28, 2012 10:53 pm

Quoting mawingho (Thread starter):
I asked someone a question related to the above sentence, and he said the wind flow from north pole to equator while the earth is rotating.

Not really. The general pattern looks like this;


Air will always flow from high to low pressure. However, due to Coriolis forces (a result of earth's rotation), any flow to the north or south will get bent. The combined effect of the bending on all the air flowing into the low from different directions is rotation. Since the direction of the Coriolis force depends on whether you're going towards or away from the equator, the rotation directions are opposite on each side of the equator.

Tom.
 
LH707330
Posts: 1491
Joined: Fri Jun 15, 2012 11:27 pm

RE: Meteorology Prevailing Wind

Wed Aug 29, 2012 3:09 am

Quoting tdscanuck (Reply 1):

Are those surface winds? How does the air get back to the highs?
 
iFlyLOTs
Posts: 493
Joined: Fri Apr 06, 2012 6:45 pm

RE: Meteorology Prevailing Wind

Wed Aug 29, 2012 4:05 am

Quoting LH707330 (Reply 2):
Are those surface winds? How does the air get back to the highs?

If I remember my meteorology class correctly, the upper level looks somewhat opposite, it would be an upper level low where the high is and an upper level high where the low is.



"...stay hungry, stay foolish" -Steve Jobs
 
mawingho
Topic Author
Posts: 41
Joined: Sun Jul 22, 2012 4:23 pm

RE: Meteorology Prevailing Wind

Wed Aug 29, 2012 3:24 pm

So the air current near the jet stream is just a Ferrel Cell?
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: Meteorology Prevailing Wind

Thu Aug 30, 2012 1:20 am

Quoting mawingho (Reply 4):

So the air current near the jet stream is just a Ferrel Cell?

The Ferrel cells are between the polar and Hadley (equatorial) cells. The jet streams runs around near the upper part of the Ferrel cells but the jet streams can move around pretty widely while the Ferrel cells don't move much.

Tom.

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