"Bernard Burton" wrote in message


The pressure at any level in the atmosphere is governed by the weight of air
above that level. For a given volume, there are more molecules, thus more
mass, when the air is cooler, and less mass when it is warmer. High pressure
then comes about due to a cold anomaly at some level in the atmosphere
above. For the global scale mid-latitude surface high pressure,
tropospheric air descends over these regions, thus warming the troposphere
there, and the cold anomaly must lie above this, and indeed is found in the
lower stratosphere.

Let us not forget our good friend Mr Coriolis shall we?


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