"Alastair McDonald" k wrote
in message ...
What caught my eye about the November figures was that although the
temperature record rose steadily the rainfall was more erratic. If the
cause
was the dreaded global warming then one might expect both figures to climb
slowly.

snip

Averaging the two sets of figures we get for Nov and Dec;
Period 1961-70 1971-80 1981-90 1991-2000
CET 4.9ºC 6.0 5.9 7.0
RR(E&W) 97mm 92 93 117

This seems to me to provide no clearer a message than the two months seen
separately. What I think it proves is that the climate is chaotic ...

snip

I don't think it does at all. I really am sorry that you choose to dismiss
my cautious explanatory suggestions without a word.

Philip Eden

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
.. .

"Alastair McDonald" k wrote
in message ...
What caught my eye about the November figures was that although the
temperature record rose steadily the rainfall was more erratic. If the
cause
was the dreaded global warming then one might expect both figures to climb
slowly.

snip

Averaging the two sets of figures we get for Nov and Dec;
Period 1961-70 1971-80 1981-90 1991-2000
CET 4.9ºC 6.0 5.9 7.0
RR(E&W) 97mm 92 93 117

This seems to me to provide no clearer a message than the two months seen
separately. What I think it proves is that the climate is chaotic ...

snip

I don't think it does at all. I really am sorry that you choose to dismiss
my cautious explanatory suggestions without a word.

Sorry, I'm afraid I didn't even read them. I'll reply again, with the
correct average for 1991-2000 CET this time!

Cheers, Alastair.

Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
.. .
I've now calculated 10-year mean monthly sea-level pressure for
each month, and from these we can get some indication of whether
changes in our monthly climate can be related to changes in circulation
... or not, as the case may be.


[Snip summary]

Period 1961-70 1971-80 1981-90 1991-2000
CET 6.2ºC 6.6 6.8 7.2
RR(E&W) 105mm 87 85 128
SSS(E&W) 57hr 69 63 60
Icelandic Low1004mb 1000 1002 999
Azores High 1020 1023 1020 1022
55N05Wppp 1009 1012 1012 1008
UK Flow dirn 260º 270 240 230
UK pr gradient 5.2mb 12.5 8.8 9.8
Westerliness I 5.2mb 12.0 7.7 8.1
Southerliness I 0.1mb 0.2 1.7 2.8

[Snip key]

To me, these fairly crude indicators reveal nothing unexpected.

Thinks "Are you going to say anything interesting then? Need I read what
follows?"

The rise in decadal temperature is consistent with the increase in
the southerliness index, probably plus a contribution from the
mean flow strength (the small westerliness index in the cold 1960s
suggests more frequent easterlies). Rainfall varies with mean
pressure at 55N05W though doubtless there are other
contributory factors. Sunshine was highest with a strong gradient
and a low southerliness index, as one might expect.

The period 1965-77 was quite cold and very sunny indeed;
this period had actually had a negative southerliness index ...
quite exceptional for an autumn/winter month averaged over
such a long period.

Summarising, you are saying that the increase in temperature is
due to more southerly winds bringing air from warmer climes. But
what is causing more sutherly winds?

The forcing factors which may be responsible for the circulation
changes are, of course, another kettle of fish.

I assumed you meant by that, you were thinking that the forcing
factors could be anthropogenic greenhouse gasses, but possibly
it was naive of me to think that the most obvious cause would be
the one you would find most attractive.

"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
.. .
Here is the same exercise for December ... a month which
has not exhibited a gradual warming trend over the last
four decades. It is one of the very few months of the year
when the 90s were cooler than the 80s and 70s:

Period 1961-70 1971-80 1981-90 1991-2000
CET 3.5ºC 5.4 5.0 4.7
RR(E&W) 88mm 96 101 106
SSS(E&W) 48hr 42 43 45
Icelandic Low1003mb 999 996 996
Azores High 1021 1022 1022 1022
55N05Wppp 1010.7 1010.2 1010.6 1009.6
UK Flow dirn 260º 250 240 230
UK pr gradient 7.0mb 11.2 10.2 9.9
Westerliness I 7.3mb 11.2 9.8 9.6
Southerliness I 0.5mb 2.5 2.6 3.0

So the pressure gradient and the westerliness index
(not really independent, of course) seem to correlate
with the mean temperature, while the southerliness
index seems to be less important than it was in
November.

Warmth is no longer correlated with the Southerlies. Why?
You have four columns of figure and ten rows of values. What
are the odds that more than one pair of the columns will match?

It is probably significant that winter
southerlies can range from very mild to very cold
whereas November southerlies are more often very
mild than they are very cold. The pressure at
55N 05W seems only loosely linked to mean rainfall ...
the gradually backing of the flow (southwesterlies are
probably wetter than westerlies ...?) may also be
important.

I said I was sorry that I had ignored your comments. All I can
say now I have read them is sorry again! I am not convinced
you have anything very profound to say here. The matches
you are making could easily have occurred by chance.

There is an overall trend towards higher temperatures and
higher rainfall, so I suspect that the main driving force is
global warming, which is being hidden in a chaotic system.

Chaotic can be used as a mathematical term to describe the
output of a system where the positive feedback is so great
that the system becomes unstable. There are two levels of
instability. The lower level is when the system oscilates, either
at a pure frequency or more likely following a 'strange attractor'
which is an oscillation which gets very close to but never
actually passes through the same point twice. That's why
it is called strange! Where more positive feedack is applied
the sytem output is 'white noise.' White noise is a term used
to describe a signal which appears to be entirely random. At
a recent meeting of the Royal Society, Professor Hoskins
described the behaviour of water vapour as random. I suspect
that the white noise he is seeing is in fact due to chaotic. Get
rid of the water vapour from the air and temperatures would
rise smoothly as greenhouse gases increase.

For a bit of fun I averaged the November aand December figures
without bothering about the diference in days. I also have
added figures for 2001-10 using the average of 2001 and 2002.

November
Period 1961-70 1971-80 1981-90 1991-2000 2001-10
CET 6.2ºC 6.6 6.8 7.2
8.0
RR(E&W) 105mm 87 85 128 153.1

December
Period 1961-70 1971-80 1981-90 1991-2000 2001-10
CET 3.5ºC 5.4 5.0 4.7
4.7
RR(E&W) 88mm 96 101 106 95.5

November and December average
Period 1961-70 1971-80 1981-90 1991-2000 2001-10
CET 4.9ºC 6.0 5.9 6.0
6.4
RR(E&W) 97mm 92 93 117 124.3

The N & D Ave. shows a rising trend in both CET and RR with
the hint of a steeper climb as we reach this decade. The danger
signs are there, if you care to look.

Cheers, Alastair.

Chaotic can be used as a mathematical term to describe the
output of a system where the positive feedback is so great
that the system becomes unstable. There are two levels of
instability. The lower level is when the system oscilates, either
at a pure frequency or more likely following a 'strange attractor'
which is an oscillation which gets very close to but never
actually passes through the same point twice. That's why
it is called strange! Where more positive feedack is applied
the sytem output is 'white noise.'
I find yr description of a chaotic system virtually unrecognisable and almost beyond
comment.However,'strange attractors' were so named because of their 'exotic' topological structure
in phase space,as opposed to the limit cycle or fixed point attractors previously known.

White noise is a term used
to describe a signal which appears to be entirely random. At
a recent meeting of the Royal Society, Professor Hoskins
described the behaviour of water vapour as random. I suspect
that the white noise he is seeing is in fact due to chaotic. Get
rid of the water vapour from the air and temperatures would
rise smoothly as greenhouse gases increase.
I find yr view of the climate system virtually unrecognisable and almost beyond comment.
Are you the A B Macdonald in the discussion section postscript to the published version of Hoskin's
talk (Proc.Trans.R.Soc.London A ,2003,p1959)?I would read Hoskin's paper carefully.After that read
an article by Tim Palmer,Weather ,1993, p314," A non linear dynamical perspective on climate change
".Hopefully,this would put yr views on dynamical systems,climate change etc on a sounder footing.
I don't suppose any amount of advice wld change the general tone of yr remarks to Philip,

--
regards,
david

"Waghorn" wrote in message
...
Chaotic can be used as a mathematical term to describe the
output of a system where the positive feedback is so great
that the system becomes unstable. There are two levels of
instability. The lower level is when the system oscilates, either
at a pure frequency or more likely following a 'strange attractor'
which is an oscillation which gets very close to but never
actually passes through the same point twice. That's why
it is called strange! Where more positive feedack is applied
the sytem output is 'white noise.'
I find yr description of a chaotic system virtually unrecognisable and
almost beyond
comment.However,'strange attractors' were so named because of their 'exotic'
topological structure
in phase space,as opposed to the limit cycle or fixed point attractors
previously known.

Well, until you come up with an alternative description I will
stick with mine. Of course you are correct about strange attractors
being a subset of attractors, but in a very simple explanation I am
not sure it is neccessary to draw the distinction.

White noise is a term used
to describe a signal which appears to be entirely random. At
a recent meeting of the Royal Society, Professor Hoskins
described the behaviour of water vapour as random. I suspect
that the white noise he is seeing is in fact due to chaotic. Get
rid of the water vapour from the air and temperatures would
rise smoothly as greenhouse gases increase.
I find yr view of the climate system virtually unrecognisable and almost
beyond comment.
Are you the A B Macdonald in the discussion section postscript to the
published version of Hoskin's
talk (Proc.Trans.R.Soc.London A ,2003,p1959)?I would read Hoskin's paper
carefully.After that read
an article by Tim Palmer,Weather ,1993, p314," A non linear dynamical
perspective on climate change
".Hopefully,this would put yr views on dynamical systems,climate change etc
on a sounder footing.

I am A B McDonald, and as such have not only read his paper
but also heard it delivered at the meeting. As I recall he restated
the conventional wisdom regarding abrupt climate change which
has been unable to find an answer to the problem of how it
occurs. In these circumstances I feel no guilt about presenting
alternative views, nor simplifications which may provide pointers
to the correct solutions.

I look forward to reading Tim Palmer's article in Weather when
I can get hold of a copy.

I don't suppose any amount of advice wld change the general tone of yr
remarks to Philip,

I did not pick this fight with Philip. He criticised me for not
commenting on his posts and I have now done so. He is not
slow to point out my errors when I post points with which he does
not agree. What is sauce for the goose is surely sauce for the
gander!

Cheers, Alastair.