On Fri, 23 Apr 2004 08:32:01 +0100, Mike Tullett
wrote:

On Fri, 23 Apr 2004 01:03:04 +0100, Dave Ludlow wrote in
m
snip
...The colour boundaries look odd too. As you say - bring back
isopleth maps. I do think this is potentially a very useful source,
though, once such problems are ironed out.

Yes, I didn't mean to complain about the idea of mapped averages
because I've always thought the previous implementation was good.
IMO, the only thing that needed changing was the addition of some
*light* colouring to help the eye when following the isopleths round
and through which the lines could still be seen.

As for the the values chosen for the colour boundaries, in many cases
they are simply awful. A colour key with linear (or if necessary,
logarithmic) values would have been better, using round figures as
much as possible. If ordnance survey maps were drawn in the same way,
they wouldn't be much use to most people...

Cheers

--
Dave

"Joe, Bedford." wrote in message
...

"Joe, Bedford." wrote in message
...

"Alastair McDonald" k
wrote
in message ...

Never mind lowland Southern England. What about the whole of Scotland.
Look at the Annual Mean Maximum Temperature map;
http://www.metoffice.com/climate/uk/...00/tmax/17.gif
and nearly all of Scotland is coloured blue which the key says is 2.4C!

No wonder visiting Sasenachs arriving in May expect to find the Pentland
Hills covered in snow!

Cheers, Alastair.



It actually says between 2.3 and 10.3 (bit of a range) I gather it means
the
peaks average 2.3 at the least.



That should read 2.4 not 2.3.

The blue that I was referring to covers from 2.4 to 12.3C. ie the boundary
between dark blue and blue is very unclear. I suppose I should not really
complain on chauvanistic grounds. Scotland is coloured blue and white,
whereas England is in red and white. But from a scientific POV would it
not be better if a scale of colours from -2C to +30C was chosen and
used consistently on all the temperature maps. The lowest colour (dark
blue) could be labelled 'below -2C' and the highest colour (dak red)
could be labelled 'above 30C.'

If that led to Scotland (and Northern Ireland) being coloured orange
in summer, surely no one would object :-?

Cjeers, Alastair.

The message
from Dave Ludlow contains these words:


I'm not sure about the science of it but I much preferred the old
contoured mapped averages. It's very hard for me to see the boundaries
between similar colours on these new maps (shades or red or blue),
particularly where are several colour changes in a small area.

And for the 10% of males who, like myself, are colourblind - they are
quite meaningless.

Phil.

From the Kyle of Sutherland - 175 feet AMSL (NH616916)
(40 miles north of Inverness)

But, Julian,
what do you make of the boundaries used between different colours?
These are, presumably, rounded figures which approximate to quint boundaries
.... is this cartographically acceptable these days, is it a whim of the
compilers who perhaps don't give a damn what is and
is not normal practice, or is it, ahem, best described otherwise
in private? Or am I plain out of date?

Philip Eden

Perish the thought! I agree that a bit of human intervention to align the
boundaries between the categories to whole numbers would make the maps much
easier to interpret. There is one specific problem; because roughly equal areas
fall into each 'bin' or category, it is impossible to tell which locations have
the extreme values for any chosen variable. For example, the deep red shading
on the temperature maps always extends across a wide area; which area is
warmest. Which mountain top is (assumed to be ) coldest? Which locations are
driest in any given month? As the key specifies the extreme value in each case,
it would be nice to know (MO - just place a cross on the maps to indicate, if
you cannot change the boundaries). .

I suspect that someone in the climate division ( Nat. Climate Information
Centre) might be following this dialogue...?

I still think that the maps represent an advance for climatology on the web
because of the amount of detail they show - such a novelty on climate sites.

Julian Mayes, West Molesey, Surrey.