On Monday, February 17, 2014 3:59:03 PM UTC, exmetman wrote:
You've all entirely missed the point I was making in my original post. I did provide evidence that Stern was talking out of his arse, and from evidence provided by the UKMO, but of course my post has ended up being hijacked and ended up in the land of phantom posts never to see the light of day. I suppose, I only myself to blame, for trying to comment on a subject so heated (parden the pun) as global warming...

Sorry Bruce. Missed this. Your point appears to have been well-made.

In article ,
Alastair McDonald writes:
But isn't the CET just a massaged set for a (small) region of the
UK? OTOH, it is longer but is it accurate?

Enormous effort was devoted to making it as accurate as possible.
Obviously the earliest part of the series is less accurate than the
rest. Gordon Manley's two seminal papers describing how he derived the
values can be found online. See:

http://www.rmets.org/sites/default/files/qj53manley.pdf
http://www.rmets.org/sites/default/files/qj74manley.pdf

As the Wikipedia article about the series says:

"The earliest years of the series, from 1659 to October 1722 inclusive,
for the most part only have monthly means given to the nearest degree or
half a degree, though there is a small 'window' of 0.1 degree precision
from 1699 to 1706 inclusive. This reflects the number, accuracy,
reliability and geographical spread of the temperature records that were
available for the years in question."

and

"Although best efforts have been made by Manley and subsequent
researchers to quality control the series, there are data problems in
the early years, with some non-instrumental data used. These problems
account for the lower precision to which the early monthly means were
quoted by Manley. Parker et al. (1992) [1] addressed this by not using
data prior to 1772, since their daily series required more accurate data
than did the original series of monthly means..."

So I think, even if you're very cautious, you can rely on the values
from at worst 1772 to be high accurate.
--
John Hall "He crams with cans of poisoned meat
The subjects of the King,
And when they die by thousands G.K.Chesterton:
Why, he laughs like anything." from "Song Against Grocers"

"John Hall" wrote in message
...


So I think, even if you're very cautious, you can rely on the values
from at worst 1772 to be high accurate.

Yes, but how good was the data the the series is based on? It was not from
Met Office approved sites, like that since 1910. Manley, and later Parker,
have done a lot of good work, but you can't make a silk purse out of a sow's
ear.

Cheers, Alastair.

I for one feel that the CET series is the one he should be using but...

The Met Office, bless 'em, have now muddied the waters so much with additional datasets for both rainfall and temperature, that we just don't know where he's getting his data!

But why these datasets only extend back to 1910 in a country that boasts a wealth of meteorological data especially from the Victorian era beat me!

On Tue, 18 Feb 2014 20:53:08 -0800 (PST)
exmetman wrote:

I for one feel that the CET series is the one he should be using
but...

The Met Office, bless 'em, have now muddied the waters so much with
additional datasets for both rainfall and temperature, that we just
don't know where he's getting his data!

But why these datasets only extend back to 1910 in a country that
boasts a wealth of meteorological data especially from the Victorian
era beat me!

This might help explain the reason for the different rainfall datasets
but, than again, it might not:
http://metofficenews.wordpress.com/2...-they-tell-us/

I confess that I don't quite follow this statement, "However, because
it is a digital series it is shorter than the EWP – the number of rain
gauges with data in our electronic archive decreases rapidly by the
early 20th Century." What in tarnation does the the fact that it is a
digital series have to do with its length? There could well be a good
reason for it being shorter but I don't see that this is it.

--
Graham P Davis, Bracknell, Berks. Mail: 'newsman' not 'newsboy'.
"Welcome to the year of the whores. People around the globe celebrate."
- BBC News subtitle

In article ,
Alastair McDonald writes:

"John Hall" wrote in message
.. .


So I think, even if you're very cautious, you can rely on the values
from at worst 1772 to be high accurate.

Yes, but how good was the data the the series is based on? It was
not from Met Office approved sites, like that since 1910. Manley,
and later Parker, have done a lot of good work, but you can't
make a silk purse out of a sow's ear.

There were a lot of very careful observers much earlier than 1910, but
of course the questions of the quality of the thermometers and the
exposure of the instrument are important ones. One of the main problems
is that the use of Stevenson screens only became standard towards the
end of the 19th century, before then the less good Glaisher stand being
used. Even earlier, there would have been no stand at all, of course.
But Manley was well aware of the problems, and spent many decades
overcoming them. To see how he did this I recommend reading the papers
to which I have provided the links.

There's also the point that the CET series has been adopted as a
standard by modern climatologists, and they wouldn't have done that were
they not convinced of its validity. Some of them will have investigated
the quality of the series much more thoroughly than it's practical for
you or I to do.
--
John Hall "He crams with cans of poisoned meat
The subjects of the King,
And when they die by thousands G.K.Chesterton:
Why, he laughs like anything." from "Song Against Grocers"

On Wednesday, February 19, 2014 10:27:06 AM UTC, John Hall wrote:
In article ,

Alastair McDonald writes:



"John Hall" wrote in message

.. .





So I think, even if you're very cautious, you can rely on the values

from at worst 1772 to be high accurate.



Yes, but how good was the data the the series is based on? It was

not from Met Office approved sites, like that since 1910. Manley,

and later Parker, have done a lot of good work, but you can't

make a silk purse out of a sow's ear.



There were a lot of very careful observers much earlier than 1910, but

of course the questions of the quality of the thermometers and the

exposure of the instrument are important ones. One of the main problems

is that the use of Stevenson screens only became standard towards the

end of the 19th century, before then the less good Glaisher stand being

used. Even earlier, there would have been no stand at all, of course.

But Manley was well aware of the problems, and spent many decades

overcoming them. To see how he did this I recommend reading the papers

to which I have provided the links.



There's also the point that the CET series has been adopted as a

standard by modern climatologists, and they wouldn't have done that were

they not convinced of its validity. Some of them will have investigated

the quality of the series much more thoroughly than it's practical for

you or I to do.

--

John Hall "He crams with cans of poisoned meat

The subjects of the King,

And when they die by thousands G.K.Chesterton:

Why, he laughs like anything." from "Song Against Grocers"

Philip Eden's comments around the inhomogeneities in the "new" CET, since Manley's death and around the MetO becoming "self-appointed guardians" of the series, need to be read in conjunction with any QA of the CET series. It is the longest temperature series in the world, but it is manifestly not the same series that Gordon Manley left.

http://www.climate-uk.com/page5.html

Another area where multiple sets of data for what is the same thing cause confusion is how temperature is visualised on the BBC weather maps, they display from one set of data (ie temperature in towns and cities), and then often speak of temperatures from another set (in the countryside) you aren't privvy to see.

I am very cynical how statistics are used not to clarify but to confuse, so if someone complains that you didn't get the temperature right last night it was far colder.. Argh that's because you were looking at the temperature in towns and cities!

"exmetman" wrote in message
...
Another area where multiple sets of data for what is the same thing cause
confusion is how temperature is visualised on the BBC weather maps, they
display from one set of data (ie temperature in towns and cities), and then
often speak of temperatures from another set (in the countryside) you aren't
privvy to see.

I am very cynical how statistics are used not to clarify but to confuse, so
if someone complains that you didn't get the temperature right last night it
was far colder.. Argh that's because you were looking at the temperature in
towns and cities!

================================================

It is impossible to put an accurate temperature for every town, village and
farm on a map of the UK. People who live in hill top farms have to use
their gumption and deduce that their temperatures will be lower than those
forecast for nearby low lying towns.

Cheers, Alastair.

"John Hall" wrote in message
...

There's also the point that the CET series has been adopted as a
standard by modern climatologists, and they wouldn't have done that were
they not convinced of its validity. Some of them will have investigated
the quality of the series much more thoroughly than it's practical for
you or I to do.

I suspect its adoption by climatologists is because it is unique, not it
because it is accurate. Since it is unique we don't have anything to compare
all the values with. And where it casts up anomallies, we are relying on the
value judgements of Manley and Parker to decide whether to ignore or
incorporate them.

Cheers, Alastair.