BS: weather question

Subject: BS: weather question
From: GUEST,leeneia
Date: 21 Feb 06 - 12:05 PM

I'm reading a book called "Meteorology Demystified." It's pretty good, but like every other book on weather I have read, it fails to explain to me why some air masses are high pressure and some are low.

For example, it says that there are low-pressure regions at the equator and and 60 degrees north and south. The equator would be a hot region and 60 N and S would be cool to cold. So how can they both be low-pressure? Can somebody explain this to me?

Subject: RE: BS: weather question
From: Dave (the ancient mariner)
Date: 21 Feb 06 - 12:11 PM

This site might help you...http://www.usatoday.com/weather/wstorm0.htm

Subject: RE: BS: weather question
From: Paul Burke
Date: 22 Feb 06 - 06:03 AM

Remember it's relative temperature difference that generates high and low pressure areas. If the ground, or sea, is warmer than the air up above, the air is heated and pressure drops. If the ground is cooler, it cools the air and pressure rises. It's not surprising that the ground is hot at the equator, but at higher latitudes, there is an interaction between the air and ground/ sea. As it goes north, the air cools faster than the sea- water holds heat better than air does. Also, the ground takes time to cool after the summer, and to warm up again after the winter, so the pressure pattern over a large land mass will be alter depending on the season.

Subject: RE: BS: weather question
From: Keith A of Hertford
Date: 22 Feb 06 - 06:20 AM

High pressure is where air is descending.
Because it warms and compresses on the way down, water vapour does not condense so you expect dry weather.
Low pressure just the reverse.

Subject: RE: BS: weather question
From: Keith A of Hertford
Date: 22 Feb 06 - 07:02 AM

why have you never wanted to be a member Leenia?

Just curious. Tell me to mind my business.

Keith.

Subject: RE: BS: weather question
From: GUEST,leeneia
Date: 22 Feb 06 - 10:48 AM

I am a member. Apparently my anti-virus software keeps removing my cookie.
--------
Thanks for the link, Dave. That and the other posts are helping. High-pressure air is descending air.

Subject: RE: BS: weather question
From: Bill D
Date: 22 Feb 06 - 11:04 AM

AV software is not supposed to mess with cookies..(that's not its job)

cookie control is 'usually' just a matter of settings in your browser. Someplace there will be a way to tell it "don't fret about my cookies to Mudcat when you are protecting me against all those others".

If you know where your cookies are stored, it should be quick to go to the menu and fix it.