In reply to Alex Caliostro's message of Mon, 03 Oct 2005 15:52:21 -0600: Master, [snip] >the conventional explanation involves the westernly flow of the upper >atmosphere which moves clockwise around the ridges and windershins around >the troughs -- the resulting sinusoid westernlies may number 3 to 5 waves >around the hemisphere > >ah, but, grasshopper, i believe you seek a greater truth [snip] Thank you for your efforts, but grasshopper has just found the greater truth. The conventional explanation of the World's weather machine as a hot air engine is completely wrong. It is in fact a steam engine. The partial pressure of water vapor at 30 ºC is 31.8 mmHg (See http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/watvap.html). When this moisture laden air cools at high altitude the partial vapor pressure drops to near zero. That means a drop in pressure of about 30 mmHg, which is about the difference in pressure between high and low pressure regions. The surrounding air then tries to rush in to fill the ensuing void. When this happens above water, vapor from just above the water surface is swept along with it, and carried up to high altitudes, where it also condenses, perpetuating the pressure differential.
Since water vapor is responsible for the pressure differential, it stands to reason that where the pressure differential is greatest, most water vapor will be involved, hence from the deepest lows comes the most rain. This also tallies with observation. This also teaches something else: The deepest low cannot exceed the maximum partial pressure of water vapor at the surface temperature. IOW as the partial vapor pressure goes up, the low gets deeper, which implies that with the higher temperatures brought by global warming, deeper lows and hence more severe storms are to be expected. Regards, Robin van Spaandonk In a town full of candlestick makers, everyone lives in the light, In a town full of thieves, there is only one candle, and everyone lives in the night.
