The recent record temperature at Heathrow

[knocker]

Doubts have been cast in certain circles of the credibility of the recent record temp at Heathrow based on a blog by climate skeptic Paul Homewood claiming the temperature of 36.7C had bee skewed by passing aircraft or a change in wind. The fact that the siting of the enclosure at Heathrow is not ideal is obviously well known to the METO and temperatures are always closely scrutinised post event, as in 2003, before verification.

 

This has been done and the claims do not stand up to scrutiny.

 

"It would be wrong to reject observations on the basis of a hunch...In this instance there is no compelling evidence to suggest the measurement is incorrect."

 

http://www.carbonbrief.org/blog/2015/07/met-office-wind-data-dispels-doubt-about-cause-of-heathrow-high-temperatures/?utm_source=Daily+Carbon+Briefing&utm_campaign=026da9fb0b-cb_daily&utm_medium=email&utm_term=0_876aab4fd7-026da9fb0b-303447709

Edited July 17, 2015 by knocker

[johnholmes]

Doubts have been cast in certain circles of the credibility of the recent record temp at Heathrow based on a blog by climate skeptic Paul Homewood claiming the temperature of 36.7C had bee skewed by passing aircraft or a change in wind. The fact that the siting of the enclosure at Heathrow is not ideal is obviously well known to the METO and temperatures are always closely scrutinised post event, as in 2003, before verification.

 

This has been done and the claims do not stand up to scrutiny.

 

"It would be wrong to reject observations on the basis of a hunch...In this instance there is no compelling evidence to suggest the measurement is incorrect."

 

http://www.carbonbrief.org/blog/2015/07/met-office-wind-data-dispels-doubt-about-cause-of-heathrow-high-temperatures/?utm_source=Daily+Carbon+Briefing&utm_campaign=026da9fb0b-cb_daily&utm_medium=email&utm_term=0_876aab4fd7-026da9fb0b-303447709

 

Interesting article

[4wd]

Well it's correct for a thermometer sited by acres of runway.
It would read differently when it was all just fields in the olden days when we had weather not climate..
The very fact Heathrow regularly reads higher than anywhere nearby is quite a big clue.

[Methuselah]

Well it's correct for a thermometer sited by acres of runway.

It would read differently when it was all just fields in the olden days when we had weather not climate..

The very fact Heathrow regularly reads higher than anywhere nearby is quite a big clue.

In other words, what you say is garbage?

Edited July 17, 2015 by Ed Stone

[hillbilly]

Not to mention two or four jet engines kicking out hundreds of degrees every minute of the day cannot claim to have no effect!

[Methuselah]

Not to mention two or four jet engines kicking out hundreds of degrees every minute of the day cannot claim to have no effect!

   

[cheese]

Well it's correct for a thermometer sited by acres of runway.

It would read differently when it was all just fields in the olden days when we had weather not climate..

The very fact Heathrow regularly reads higher than anywhere nearby is quite a big clue.

Why doesn't Heathrow hold the UK temperature record then, if passing airliners have such a massive impact on temperature readings? Previously it was Cheltenham, and now it's some rural area of Kent, that, as far as I'm aware, has no influence from airliners. Heck, Heathrow doesn't even hold the London record - that honour goes to Kew Gardens.

 

What about London City Airport? That's reasonably busy. London Weather Centre is also situated on a rooftop in central London, so would be an obvious candidate for artificially boosted temperatures given the amount of concrete and tarmac.

 

What about Gravesend and Northolt? What's their excuse for regularly appearing in the UK's hottest?

[Relativistic]

Why doesn't Heathrow hold the UK temperature record then, if passing airliners have such a massive impact on temperature readings?

No one said a massive impact. If the record was broken my a mere 0.2C then only a very small temperature boost could have caused the record to go, which, given the Heathrow station's surroundings, doesn't seem too inconceivable.

Just my opinion.

Edited July 17, 2015 by 22nov10blast

[Richard2901]

The Brogdale record was clearly shown to be over-inflated garbage by Philip Eden and Stephen Burt and it's a disgrace it's accepted as legitimate. This falls in to the same category. All readings taken at airport heat islands are nothing but junk and I certainly have no interest in them.

[chionomaniac]

Technically though, unless the thermometer was attached to the back of a jet engine, it was still the temperature recorded though in that locale? So even though there may not have been an airport present hundreds of years ago and the temperature my have been lower in times gone past, it is still a valid reading in today's time (or is it still not valid because modern life exists)? ( Or furthermore do we have to take account of every inflated recording in every station that may be higher because of urban effects etc and adjust them all and pretend that the temperature is not as high as recorded?) 

 

It is what it is because last time I looked, aeroplanes, cars, buildings etc do in fact exist.

[stainesbloke]

Technically though, unless the thermometer was attached to the back of a jet engine, it was still the temperature recorded though in that locale? So even though there may not have been an airport present hundreds of years ago and the temperature my have been lower in times gone past, it is still a valid reading in today's time (or is it still not valid because modern life exists)? ( Or furthermore do we have to take account of every inflated recording in every station that may be higher because of urban effects etc and adjust them all and pretend that the temperature is not as high as recorded?) 

 

It is what it is because last time I looked, aeroplanes, cars, buildings etc do in fact exist.

Lol, good point! Why query a reliably recorded temperature? Should we cease recording temperatures at all major airports around the world then?

[knocker]

Technically though, unless the thermometer was attached to the back of a jet engine, it was still the temperature recorded though in that locale? So even though there may not have been an airport present hundreds of years ago and the temperature my have been lower in times gone past, it is still a valid reading in today's time (or is it still not valid because modern life exists)? ( Or furthermore do we have to take account of every inflated recording in every station that may be higher because of urban effects etc and adjust them all and pretend that the temperature is not as high as recorded?) 

 

It is what it is because last time I looked, aeroplanes, cars, buildings etc do in fact exist.

 

Yes that is the point which I think many are missing. It's not about the position of the enclosure but whether local site peculiarities, outside of the standard conditions for that site, may have unduly influenced the temperature. It's got nothing to do with UHI, frost hollows, wind tunnels, etc.

 

This very subject arose after the 2003 heatwave and Stephen Burt and Philip Eden published an in depth analysis which is worth a read.

 

The August 2003 heatwave in the United Kingdom: Part 2 – The hottest sites

 

http://onlinelibrary.wiley.com/doi/10.1256/wea.10.04B/epdf

Edited July 18, 2015 by knocker

[johnholmes]

So after all the 'heat' this thread generated what is the answer?

Is the site at Heathrow not pretty representative of the concrete and other hard surfaces most of us live with. Our back gardens perhaps being mini 'havens' of some greenery from the concrete and asphalt jungle many of us have to live with?

I do dislike the idea that any organisation, Met O or any other is 'fiddling' the figures. That is nonsense and a slur on those employed in these organisations. For what purpose would it be done? I well remember observing myself and the idea of 'fiddling' the result to get a record, high or low for temperature, sunshine or rainfall was something that never ever entered my head.

[Polar Maritime]

Yes John rather pathetic to say the figures are 'fiddled', What is there to gain on spreading this lie? Other than feeding the less knowledgeable with misinformation coursing a whole load of confusion. The mind boggles!  

Edited July 18, 2015 by Polar Maritime

[4wd]

Who says it's fiddled?
This is classic - mis-represent an argument then attack your own mis-representation.

The point is that acres of runway get hot in the sun, and retain heat overnight - therefore they are usually going to give higher readings than a more correctly located rural station.
Even the SE is not *mostly* built up yet.  
 

Edited July 18, 2015 by 4wd

[DAVID SNOW]

Would the temperature recorded at Heathrow that day be any different if say the airport had been closed all day? Genuine Q.

[johnholmes]

Would the temperature recorded at Heathrow that day be any different if say the airport had been closed all day? Genuine Q.

Difficult to say David but somehow I doubt it. If one looks at the diagrams provided to me there is nothing to suggest that jet eflux was responsible for the temperature recorded.

[johnholmes]

Who says it's fiddled?

This is classic - mis-represent an argument then attack your own mis-representation.

The point is that acres of runway get hot in the sun, and retain heat overnight - therefore they are usually going to give higher readings than a more correctly located rural station.

Even the SE is not *mostly* built up yet.  

 

 

Perhaps my misunderstanding of what has been said about this issue. I am not trying to be antagonistic so if my phrase annoys I apologise. 

[Relativistic]

Who says it's fiddled?

Exactly what I thought. No one even suggested fiddling.

Anyway. Even if you do try to account for areas being too urban, where do you draw the line between what is too urban and what isn't?

Perhaps Heathrow is an exceptional location because of where it is situated. But then you have stations like Benson which can also be exceptional due to where they are situated (ie, in frost hollows), does that make readings there invalid?

[Nouska]

Would the temperature recorded at Heathrow that day be any different if say the airport had been closed all day? Genuine Q.

 

If heating of the tarmac is the issue, probably not.

 

On the subject of airport temperatures, our local record was set back in 1947 when the site was just a military landing strip, surrounded by green space and a big river. In the intervening years, it has become much more built up with new runways for commercial use. Despite this added budget of heat retaining material, the record still stands to this day. This year may still beat it but the several heat pulses have been nearly two degrees short of the record.

 

Edit to query.....would closure have made it even hotter if clearer skies and no contrail build up?

Edited July 18, 2015 by Nouska

[DAVID SNOW]

Thank you for your interesting replies

[knocker]

Who says it's fiddled?

This is classic - mis-represent an argument then attack your own mis-representation.

The point is that acres of runway get hot in the sun, and retain heat overnight - therefore they are usually going to give higher readings than a more correctly located rural station.

Even the SE is not *mostly* built up yet.  

 

 

The enclosure isn't on a runway. People are still missing the point which is whether local site peculiarities, outside of the standard conditions for that site, may have unduly influenced the temperature. The METO have obviously concluded this is not the case.To quote Burt and Eden from the article posted.

 

 

Summary

 

Some doubt attaches to almost all of the highest values reported, mainly as a result of local site influences or shelter. There are few perfectly exposed climatological stations and it can be argued that even those with a less than ideal exposure or local site influences do represent conditions within their immediate locality. Whilst this could be argued, it misses the point – namely, to make an accurate assessment of the highest air temperatures attained under standard conditions during the summer 2003 heatwave.

 

The Kew Gardens, Wisley and Heathrow values, while appearing slightly high, do appear to withstand critical scrutiny and comparison with other local observations.

However, in the opinion of these authors there remains considerable doubt over the degree to which the values reported from Faversham and Gravesend are  climatologically representative of those localities. The reported maxima from these sites should not be quoted without reservation

Edited July 18, 2015 by knocker

[Polar Maritime]

I think some seem to think some stations are purposly put in areas to give higher readings, Hence the word 'Fiddle'.

[Fourty Point Three Degrees]

this thread reminds me of the 42C recorded at Wisley Airfield in July 2006 which caused a big debate and finally it was never accepted.   

[hillbilly]

Anyone any idea what these official stations do to calibrate their thermometers and how often it is performed?