Subject: Re: TWEETERS digest 728
Date: Jul 17 00:50:46 1996
From: "Jack Bowling" - jcbowling at mindlink.bc.ca




>>PERIOD III 1000-1100 Winds shift slightly westward, but still
>> in the 40+ knot range, at 1009, when the
>> skies break in a manner I've never seen
>> before: it was like a chemistry
>> experiments in high school, in which two
>> drops of clarifying agent into the
>> solution produces instant clarity. The
>> trailing feeder bands dissipated in a
>> matter of seconds. The blue sky left
>> behind was the most intense Anderson and
>> I have ever seen. Areas like Windmill
>> Point, the barrier islands, Buckroe,
>> the high span at Fisherman Island looked
>> like miniature toys that one might reach
>> out and touch. No haze or pollution
>> marred the view for the next several

This is a great description of the subsidence zone in the wake of a
hurricane. The strongest upward motion in a hurricane is in the east or
northeast quadrants, with a compensating strong downward region of subsidence
(subsiding air) in the west or southwest quadrants. This subsiding air
leads to rapid dissipation of cloud, and given the scrubbing of aerosols
that have already taken place with the passage of the hurricane, leads to
the crystal clear air in this zone. I am not sure if there is any
"tropopause folding" in this situation (the tropopause is the boundary between
the lower troposphere where the weather occurs and the higher stratosphere
which holds all the ozone) which occurs when there is a drastic lowering of
of the tropopause under srongly subsident conditions. If there were, this
could also lead to a bluer sky since ozone is highly reactive and would
"clean up" a lot of the free radicals floating around in the upper troposphere.
I'm gonna have to get me a seat on one of those spotter planes one day.

- Jack
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*Jack Bowling *
*Prince George, BC *
*jcbowling at mindlink.bc.ca *
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