Is it time to replace the CET?

[PersianPaladin]

In these days where records seem to be continuously broken and the old mean-ranges prior to 1971 are increasingly looking less relevant; should we be scrapping the CET as an average record of temperatures for England and Wales? After all, it may be the longest running temperature series in the UK but surely there are serious issues with its representativeness for England; particularly as climate change accentuates the difference between western and eastern regions and the monthly mean baseline grows ever higher?

What are your thoughts on a WOET? (Whole Of England temperature series). Or would this simply be a waste of time?

[Frozen Lands]

In these days where records seem to be continuously broken and the old mean-ranges prior to 1971 are increasingly looking less relevant; should we be scrapping the CET as an average record of temperatures for England and Wales? After all, it may be the longest running temperature series in the UK but surely there are serious issues with its representativeness for England; particularly as climate change accentuates the difference between western and eastern regions and the monthly mean baseline grows ever higher?

What are your thoughts on a WOET? (Whole Of England temperature series). Or would this simply be a waste of time?

I mentioned this some time ago about splitting it into several areas such as Northern England CET, Midlands CET, Souther CET and then a separate Welsh and Scottish CET......but if I remember correctly I was largely rebuffed for it

I still thing it would be a better idea and so agree with you

[WhiteFox]

I mentioned this some time ago about splitting it into several areas such as Northern England CET, Midlands CET, Souther CET and then a separate Welsh and Scottish CET......but if I remember correctly I was largely rebuffed for it

I still thing it would be a better idea and so agree with you

Apart from the names (as CET stands for Central England Temperature, so it wouldn't make sense!) I believe the figures you are mentioning already exist. The CET is simply the headline figure which is used mainly because it has been running for so long. It'll never be dropped, but the stats are already out there for other regions.

[Don]

I don't think that the CET should be scrapped, I think it's good the way it is. However, what I don't understand is why the Met Office are still comparing temperatures to the 1961-90 average and not the 1971-2000 when we are in 2007! Surely they should be using the latter by now.

[Nick H]

In these days where records seem to be continuously broken and the old mean-ranges prior to 1971 are increasingly looking less relevant; should we be scrapping the CET as an average record of temperatures for England and Wales? After all, it may be the longest running temperature series in the UK but surely there are serious issues with its representativeness for England; particularly as climate change accentuates the difference between western and eastern regions and the monthly mean baseline grows ever higher?

What are your thoughts on a WOET? (Whole Of England temperature series). Or would this simply be a waste of time?

Not sure I follow. The fact that in the past 12 months monthly temperatures have risen sharply against the 30 year mean is not an argument for scrapping the series as an historical record of temps.

I'm not sure your assertion that AGW "accentuates the difference between west and east" is correct. Do you have evidence that the east has seen more accelerated temps than the west since 1988?

With regard to the representativeness issue, I don't see whole including the extreme south of England and the far north of England would make any substantial difference anyway. The two would probably cancel each other out and therefore have a negligible impact, being virtually the same as the CET. So it's leave the CET as it is for me.

[Thundery wintry showers]

We already have a whole-of-England temperature series run by the Met Office, which they have traced quite some way back.

It won't replace the CET but it complements it nicely; surely the more temperature measures we have, the better? I reckon that the CET is probably favoured because the records go back to 1659 and it helps to have a relatively homogeneous record of something.

[PersianPaladin]

Not sure I follow. The fact that in the past 12 months monthly temperatures have risen sharply against the 30 year mean is not an argument for scrapping the series as an historical record of temps.

I'm not sure your assertion that AGW "accentuates the difference between west and east" is correct. Do you have evidence that the east has seen more accelerated temps than the west since 1988?

With regard to the representativeness issue, I don't see whole including the extreme south of England and the far north of England would make any substantial difference anyway. The two would probably cancel each other out and therefore have a negligible impact, being virtually the same as the CET. So it's leave the CET as it is for me.

Cancel each other out? I think not. There can be marked differences either side of the pennines in summer and winter; temperature wise. The south-east and the north-east are also somewhat excluded from the measurement; which would likely bring down or increase the values respectivley. I think the whole issues is representative-ness; and I think the Met-Office measurements are arguably more accurate than the CET measurements.

Historical records? We are making history now.

[Stratos Ferric]

In these days where records seem to be continuously broken and the old mean-ranges prior to 1971 are increasingly looking less relevant; should we be scrapping the CET as an average record of temperatures for England and Wales? After all, it may be the longest running temperature series in the UK but surely there are serious issues with its representativeness for England; particularly as climate change accentuates the difference between western and eastern regions and the monthly mean baseline grows ever higher?

What are your thoughts on a WOET? (Whole Of England temperature series). Or would this simply be a waste of time?

PP, that's like saying scrap mph as a measure of speed because cars can go faster now than fifty years ago, or scrap minutes and hours as a unit of time because life nowadays is generally lived at a faster pace.

The WHOLE point about longitudinal data is that it shows changes. If you keep changing the baseline then it's impossible to know how much things have changed. In rugby (either code) reporters will occasionally mention a record victory - but given that tries and conversions are now worth more than they used to be how can you say that meaningfully?

I'm not sure thatyour points about W-E stack up. There has always been a difference, and always will be. CET attempts to define an area in between, but even within this relatively small area there are minor variations in climate.

Changes over time are PRECISELY what CET is there to show. I think you ned to explain what you mean by it being unrepresentative. Given that day by day it is based on today's temperature you might as well suggest that the FTSE100 is not representative of the state of the stock market in the UK because the index is now around 25 years old. It still measures precisely what it was designed to measure, just like a metre rule does, or your thermometer.

I suspect that what you're arguing is that the thirty year mean used as the climatic norm is unrepresentative. That is true in the same way that averaging your speed in a car if you spend ten seconds accelerating isn't representative of your speed at the end of those ten seconds. However, that is a problem of any changing environment, and the issue is one of maths, not of the index or unit used.

Please let's not go down the new labour route of redefining how things are measured to make them look more palatable. As discussed last w/e when one of our number was hollering about 80F having been breached (so far as I'm aware it wasn't), and as TM succinctly put it in response, meteorology is a science and a discipline of measurement and it is absolutely founded on being able to measure precisely in order to make precise comparisons.

We already have a whole-of-England temperature series run by the Met Office, which they have traced quite some way back.

It won't replace the CET but it complements it nicely; surely the more temperature measures we have, the better? I reckon that the CET is probably favoured because the records go back to 1659 and it helps to have a relatively homogeneous record of something.

Precisely

Not sure I follow. The fact that in the past 12 months monthly temperatures have risen sharply against the 30 year mean is not an argument for scrapping the series as an historical record of temps.

I'm not sure your assertion that AGW "accentuates the difference between west and east" is correct. Do you have evidence that the east has seen more accelerated temps than the west since 1988?

With regard to the representativeness issue, I don't see whole including the extreme south of England and the far north of England would make any substantial difference anyway. The two would probably cancel each other out and therefore have a negligible impact, being virtually the same as the CET. So it's leave the CET as it is for me.

There is far more variation in our climate w.r.t temperature N-S and with altitude, and there always will be (simple physics), than there is E-W. Rain will ALWAYS be more plentiful in the W and on uplands - again simple physics. AGW will do absolutely nothing to alter that so long as the earth continues to spin w-e and the sun continues to shine in the annual plane that it does.

I mentioned this some time ago about splitting it into several areas such as Northern England CET, Midlands CET, Souther CET and then a separate Welsh and Scottish CET......but if I remember correctly I was largely rebuffed for it

I still thing it would be a better idea and so agree with you

Given that CET stands for CENTRAL ENGLAND TEMPERATURE, Scottish CET is something of a non sequiter. CET is not shortform for "average temperature", even though some people seem to think it is.

[PersianPaladin]

PP, that's like saying scrap mph as a measure of speed because cars can go faster now than fifty years ago, or scrap minutes and hours as a unit of time because life nowadays is generally lived at a faster pace.

Nope...this is not about a unit of measurement.

I'm not sure thatyour points about W-E stack up. There has always been a difference, and always will be. CET attempts to define an area in between, but even within this relatively small area there are minor variations in climate.

Why define an area in-between? The whole point is to get a representative sample; not on some artificial select area that happens to be the most highly recorded area.

Please let's not go down the new labour route of redefining how things are measured to make them look more palatable. As discussed last w/e when one of our number was hollering about 80F having been breached (so far as I'm aware it wasn't), and as TM succinctly put it in response, meteorology is a science and a discipline of measurement and it is absolutely founded on being able to measure precisely in order to make precise comparisons.

Yes, I would like an accurate representative geographic measurment of temperature in England. We do not have that with the CET.

There is far more variation in our climate w.r.t temperature N-S and with altitude, and there always will be (simple physics), than there is E-W. Rain will ALWAYS be more plentiful in the W and on uplands - again simple physics. AGW will do absolutely nothing to alter that so long as the earth continues to spin w-e and the sun continues to shine in the annual plane that it does.

The CET does not extend fully into northern england anyway....and of course, there is altitude to consider which I agree on. Still, its about getting the most geospatially representative data as possible. Until then, it is merely our own estimations. As far as I'm concerned; the north-east of England has a climate of its own, and the same with Cumbria.

Cutting some triangle in central western england and giving it so much attention as English average monthly temp trends doesn't cut the mustard with me. Maybe I should just stick with the MetOffice stats?

[summer blizzard]

In a word, no.

[johnholmes]

drop the capital mate, its seen as bad manners.

Make your points quietly !

[PersianPaladin]

drop the capital mate, its seen as bad manners.

Make your points quietly !

Apologies...it was highlighted in bold because originally I was going to post inside one enveloped quote - distinguishing my comments from Stratos' post.

[johnholmes]

The WHOLE point about longitudinal data is that it shows changes. If you keep changing the baseline then it's impossible to know how much things have changed.

that sums up the reason for keeping it and not changing the 'base line'

Apologies...it was highlighted in bold because originally I was going to post inside one enveloped quote - distinguishing my comments from Stratos' post.

ok thanks

[Don]

The WHOLE point about longitudinal data is that it shows changes. If you keep changing the baseline then it's impossible to know how much things have changed.

I very much agree.

[PersianPaladin]

The WHOLE point about longitudinal data is that it shows changes. If you keep changing the baseline then it's impossible to know how much things have changed.

Changed within a restricted area of England.

[pottyprof]

I agree with keeping the CET. It is a good reference point but how reflective is it of the UK climate? I can't see any harm in a new set of data based on say quarters. NW/NE/SE/SW. This would be more constructive given the huge variations between these areas and a fairer reflection in how local climate is changing.

Just my thoughts..

[acbrixton]

Yes of course the CET must be retained for the reasons given above. However there is something to be said for adding regional averages too. More importantly,perhaps, is the need to use a 10 year rolling average in addition to the "fixed" 30 year mean at a time of noteably changing baselines.

Regards

ACB

[The PIT]

Clunk click Mods!!!!

[pottyprof]

Clunk click Mods!!!!

Sorry PIT.. You have my attention.. What were you saying??

Oh that's right.. nothing constructive..

For your information, I don't believe that the CET does anything other than provide long term data for the CET area and it certainly shows nothing of interest for our area. On the other hand you have a fair bit of data and don't show how CET temps differ from our local data.

[Roger J Smith]

The CET must be kept at all costs, and every measure necessary should be taken to ensure that it measures an average temperature that can be compared with earlier readings in such a way that one can reasonably assume that if today's weather happened in 1761 or whatever, this is the value they would have observed, adjusted by whatever the change in the environment then might produce.

As I've stated in other discussions, part of the upward temperature trend in many cases is due to expanding urbanization. It is not possible to factor this out, nor should anyone try to do so, because urbanization is some considerable part of global warming, although I do not mean to say it is the cause of it.

My belief is that the average temperature has risen 1.5 to 2 C degrees, of which 0.5 to 1.0 C is due to expanded urbanization, and the other degree or so is due to increased heating of the atmosphere in general.

These issues make the maintenance of a long-term temperature series very tricky. One observer might say, well this station we are using is now in an urban heat island and it wasn't formerly in one, so we should replace it with a more rural station nearby. But is that the right or the wrong way to maintain integrity of the series?

I leave these problems to people who get paid to figure them out.

[Stratos Ferric]

Nope...this is not about a unit of measurement.

Why define an area in-between? The whole point is to get a representative sample; not on some artificial select area that happens to be the most highly recorded area.

Yes, I would like an accurate representative geographic measurment of temperature in England. We do not have that with the CET.

The CET does not extend fully into northern england anyway....and of course, there is altitude to consider which I agree on. Still, its about getting the most geospatially representative data as possible. Until then, it is merely our own estimations. As far as I'm concerned; the north-east of England has a climate of its own, and the same with Cumbria.

Cutting some triangle in central western england and giving it so much attention as English average monthly temp trends doesn't cut the mustard with me. Maybe I should just stick with the MetOffice stats?

a/b: PP - you sound like the kind of peson who buys a can of blue paint and then complains when it isn't pink. The CET does EXACTLY WHAT IT SAYS: i.e. it represents the temperature across CENTRAL ENGLAND. As others have said, and as Philip's site shows, there are separate indices available for other parts of the UK. herefore, there are accurate measurements: alternatively, you could just go and access the data yourself and create your own - a bit of the modern malaise there methinks.

Why would the CET extend into northern England? Again, the clue is in the title. CENTRAL England Temperature. You might as well complain that the Trans-Siverian railway doesn't start from Durham.

I really don't see what your problem is, and the solution you're not proposing doesn't seem to answer the problem you haven't defined. You're not one of my clients in disguise are you?

Changed within a restricted area of England.

PP:

On the one hand you're complaining that CET is not repreresentative because it fails to pick up E-W variation. On the next you're suggesting a single measure for the whole of England. By definition this latter will average across even wider variations and if you're point is that CET is meaningless because it's not representative than a scale drawn from across an even wider area is even less representative.

The other problem is that, as with any index, the more exhaustive its input, the moreit simply tends to average out all of the peaks and troughs.

These are different measures for different things. There is NOTHING wrong with CET. You can make a case for additional measures as well as CET, but you're certainly not making a cogent case for "instead of". CET isn't broken and doesn't need fixing. What is at issue is people's misuse of measures and statistics.

Sorry PIT.. You have my attention.. What were you saying??

Oh that's right.. nothing constructive..

For your information, I don't believe that the CET does anything other than provide long term data for the CET area and it certainly shows nothing of interest for our area. On the other hand you have a fair bit of data and don't show how CET temps differ from our local data.

Got to disagree there Potty, unless you've got the text book that suggests a completely different climatic regime between the CET zone and S Yorks. You're on the margins of the zone and, for sure, on any given day CET will differ from your local readings, but over a long period it will be a darn good indication of the general climate across all of England, particularly if you understand the subtle local variations (e.g. mountain tops are wetter and colder etc.).

[Thundery wintry showers]

Aye; there is, for example, a very strong correlation between CET and the mean temperature in the North East, despite this region not being close to coming within the 'CET' zone.

Even Scotland and Northern Ireland show a reasonably strong correlation; it seems that Scotland warmed less than England during the 1990s but has then caught up during the 2000s.

[Stratos Ferric]

The CET must be kept at all costs, and every measure necessary should be taken to ensure that it measures an average temperature that can be compared with earlier readings in such a way that one can reasonably assume that if today's weather happened in 1761 or whatever, this is the value they would have observed, adjusted by whatever the change in the environment then might produce.

As I've stated in other discussions, part of the upward temperature trend in many cases is due to expanding urbanization. It is not possible to factor this out, nor should anyone try to do so, because urbanization is some considerable part of global warming, although I do not mean to say it is the cause of it.

My belief is that the average temperature has risen 1.5 to 2 C degrees, of which 0.5 to 1.0 C is due to expanded urbanization, and the other degree or so is due to increased heating of the atmosphere in general.

These issues make the maintenance of a long-term temperature series very tricky. One observer might say, well this station we are using is now in an urban heat island and it wasn't formerly in one, so we should replace it with a more rural station nearby. But is that the right or the wrong way to maintain integrity of the series?

I leave these problems to people who get paid to figure them out.

Roger, agree with the sentiments above though I'd challenge the detail.

Firstly, CET uses non-urban sites, for preciseley the reasons you infer. Yes, along the way there have had to be changes. These can be managed fairly tightly if, in the move from site A-B you have long time series data for both sites so that you can understand, in a range of conditions, if, and how, behaviour at the sites varied.

Urbanisation and warming of the atmosphere go hand in hand. The impact of urbanisation itself is actually very local in the vast majority of instances and across most parameters of atmospheric measurement. It is generally the direct consequence, however, for things like CO2 and particulate emission that has the bigger impact, and these are general not local. The bigger influence, therefore, of urbanisation is in its surrogacy as a measure of economic activity, with (now acknowledged) knock-on effects for climate change.

Aye; there is, for example, a very strong correlation between CET and the mean temperature in the North East, despite this region not being close to coming within the 'CET' zone.

Even Scotland and Northern Ireland show a reasonably strong correlation; it seems that Scotland warmed less than England during the 1990s but has then caught up during the 2000s.

Exactly: it is all but inconceivable that the CET would be in the grip of a three month drought whilst in Sheffield a later day Noah was building and using an ark. Similary a bitter month in CET-land would NOT ever be matched by a balmy one in Sheffield.

You could make an argument suggesting that the far N+NW of Scotland is not served, and Scotland as a whole is perhaps poorly served by CET, but given that climate generally operates across hundreds of miles (I'm excluding niche micro-climates in this) CET is a good indicator for all of the UK.

[shuggee]

I love the way this old chestnut comes around every 9 months or so.

As others have said, the CET measures the temp ranges across Central England, simple. Nothing needs to be changed to measure the temps in that area - it does what it says on the tin.

If the argument is that it doesn't represent Cornwall or Ayrshire or Shetland - then use a different measurement - the E&W series or the Scottish averages.

The beauty of the CET is its longevity - 300+ years of measurements from the same longitude and latitude on the globe. Useful for comparison.

I'm not really sure what the argument is...!

[Stratos Ferric]

...

I'm not really sure what the argument is...!

I'm not sure that PP is sure is either given the conflicting points he's making. I think he might be feeling a bit miffed because Chubby Prescott's (hey - where has HE gone?) plans for a NE assembly never really got off the ground.