"Graham P Davis" wrote in message
news:20150923114125.5ad899d2@home-1...
On Wed, 23 Sep 2015 02:30:27 -0700 (PDT)
xmetman wrote:

Yes today is the autumn equinox, and as Carol Kirkwood pointed out on
the Breakfast TV weather the start of the 'astronomical' autumn,
which to me is much more preferable to the 'meteorological' autumn.
They are both 'astronomical' in reality, it's just that in the days
before computers it was much easier for climaticians (?) to calculate
the mean value for a particular season by adding up just three
numbers rather than 90 which entailed a bit more work - well that's
my theory.

You may be right in it being the lazy solution but it's also the better
one as it matches the seasons better than the astronomical one.

In the northern hemisphere, the maximum temperature occurs near the end
of the third week of July and the minimum near the third week of
January. These are only a few days from the mid-point of the
meteorological seasons.

If the astronomical calendar is used, the middle of summer would be at
the end of the first week of August with mid-winter's day being at the
end of the first week of February. Also, December would be largely an
Autumn month and March would be a Winter one. The astronomical calendar
just doesn't tally with climatological reality.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
Posted with Claws: http://www.claws-mail.org/



You may find this graph of average daily max/min temperature for the period
1976 to 2005 at Wokingham of interest.

http://www.woksat.info/wwp/graav7605.gif

--
Bernard Burton

Wokingham Berkshire.

Weather data and satellite images at:
http://www.woksat.info/wwp.html



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