wrote in message
...
snip
It's really from an agricultural standpoint that I'm asking (doing
this on behalf of a collection of allotment holders around the
country). snip


It's the categories and definitions of stuff that I'm after

I thought it would be easier to find, given that there's a lot of
work
in the area of climate change, and if we're going to measure that,
then we need to know the type of climate for a number of given
locations or areas to measure from!

.... OK; I'm not going to be able to answer your specific points,
especially on the various definitions, because there are a number of
schemes that have been developed over the recent decades (and by that
I mean at least 60-odd years), and each one has merits and drawbacks.

I'm looking at a book entitled: "The Climate of the British Isles" (a
famous publication in the 'weather' world), Ed. Chandler and Gregory.
A wealth of facts and figures - it looks quite 'dry' (sorry!) if you
flick through it quickly, but there is a wealth of information
contained therein, though unfortunately, as the book was first
published in 1976, the data will obviously not necessarily apply to
current conditions. However, the broad ideas are sound.

In the final chapter ('Regional Climates') several schemes are
discussed for climate classification, and the one that comes closest
to that which you are interested in follows from work by one of the
co-editors: S. Gregory (references contained within the book).

At page 338, he publishes a map of the British Isles, which shows
regional climates " based on the length of the growing season, annual
rainfall conditions and the seasonal incidence of rainfall ".

To use your three examples:-
Lands End

This is in his class "AMw", which translates as follows:
A = length growing season** .. of 9 or more months.
M = (precise definition in the book), but essentially .. high rainfall
does not occur frequently (high, by implication from the table, is
=1250 mm a year), yet low rainfall (again, this would seem to be
=750 mm) is infrequent or not experienced.
w = maximum rainfall in the winter half of the year.

and for Inverness something like
This is in class "BD2"
B = growing season of 7 or 8 months.
D = at least 30% probability of annual rainfall = 750 mm. [ i.e.,
these are relatively 'dry'/D areas ]
2 = maximum rainfall in second-half of the year.

and for East Anglia
This is in class "BDs" [ essentially a slight variant of Inverness ]
B = growing season of 7 or 8 months.
D = at least 30% probability of annual rainfall = 750 mm. [ i.e.,
these are relatively 'dry'/D areas ]
s = a 'weakly developed tendency for a summer rainfall maximum'.

**BTW, the 'length of growing season' is based on accumulated
temperatures, with the critical value being 6°C. The book goes into
more detail on this aspect.

I can't comment further sadly - it's not really my area of expertise,
but you get the idea of how this author has gone about things, and
also how others might approach the problem.

Incidentally, though you can purchase second-hand copies of these
books I've mentioned, in this particular case, because it's a seminal
work, I know that many public libraries will either have a copy on the
shelf, or be able to reserve a copy.

Martin.


--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023