Heathrow Hijinks

Guest Post by Willis Eschenbach

Once again the Week In Review-Science Edition over at Dr. Judith Curry’s website brings up interesting news. It appears that the first of July was hot in the UK, and among others the airport at Heathrow set a record high temperature for the date.. This led to a bit of a flap over in the land of the Anglo-Saxophones.

The British newspaper The Telegraph said that they thought the record was bogus. They theorized that it was caused by jet exhaust and wind changes, which seems quite reasonable to me. In response, the Met Office swung into action and posted up a page on their “Carbon Sense” blog saying that no, it was a break in the clouds that did it, the extra sun raised the temperature. Here’s their money graph:

heathrow temp vs radiationFigure 1. Graph of solar radiation and temperature at Heathrow for the hottest hour on July 1, 2015

They used this graph to claim that it’s the sun, stupid … but the first problem is, according to their graph, about twenty minutes after the peak in temperature, the clouds parted a bit and the solar input jumped up again to nearly as high as it had gone before … but the temperature didn’t change in the slightest. Well, that’s not entirely true. The second time the sun strength increased, the temperature went down. If the temperature spike early in the record were from the sun, does it make sense to you that a subsequent solar spike twenty minutes later would lead to no warming at all?

The second problem is that the sun strength stayed high,  but the temperature started dropping before the succeeding decrease in sun strength.

In any case, they kindly provided the data used in the graph, kudos to them for that, plus the wind direction and strength data so we could see that it’s the sun, stupid … except for one detail. They are using that graph and data  to claim that it is the sun, not the wind direction as claimed by the Telegraph, that caused the temperature spike.

With the data we can see that the third problem with their claim is that, for at least this short period, the correlation of temperature with wind direction (0.63) was 50% stronger than the correlation of temperature with sunshine (0.42). So their own data, specially provided to back up their claims, actually disagrees with their claims.

Of course, this means nothing about the longer term. However, for the short-term period around the temperature spike, they certainly have not established their case, so we’re still left with the question of what caused the temperature peak.

Some insight into this question comes from the UK Met Office. They’ve kindly provided these examples of the highest record-setting temperatures in the UK on the first of July, 2015 (see the 7 July 2015 entry here )

uk record temps july 1 2015Figure 2. Highest temperature records set on the first of July, 2015

Now, looking at Figure 2 we have two possibilities. Either a) human actions are increasing the surface air temperatures recorded at Heathrow, or b) by an astounding historical coincidence, the UK’s largest airport was built precisely on top of the warmest spot on the island … I’m going with a) myself, although YMMV.

So being an inquisitive type of fellow, I decided to take a back-of-the-envelope look at just how much actual thermal energy is released at Heathrow. This doesn’t include the heating effect of all those square metres of runway asphalt, but it’s a start.

A bit of research shows the CO2 released at Heathrow by the actual burning of fuel on the ground and in takeoff and landing (under 3,000 feet [900 m] elevation) is about 1.6 million tonnes of CO2/year. Most of this is in the form of jet fuel, which sounds all high-techy but which is actually kerosene.

Using the conversion factor for kerosene of 71.5 kg of CO2 per gigajoule of energy, this converts to 2.24E+16 joules/year, or 6.13E+13 joules per day, of heat solely from the burning of the fuel.

Now, how much would this release of energy warm the air? Well … how much air are we considering? Heathrow covers a large area, 1227 hectares. So let’s figure the air above Heathrow up to the 3,000 feet elevation under which they’re counting the CO2 emitted.. That’s about 1.12E+10 cubic metres of air, or about 1.43E+10 kg of air.

The specific heat of air is easy, it’s about 1 kilojoule per kilogram per degree C. And we can probably figure that about 30% of the energy is used to produce mechanical work, with the rest lost as heat.

So, imagine that we could put a transparent air-tight dome over Heathrow 3,000 feet (900 m) tall, and one day we burned 6.13E+13 joules worth of kerosene inside the dome, and 70% of that energy went into heat … how much would that raise the air temperature?

Short answer? It would give about a 3°C temperature rise, which is 5.4°F.

Now, of course as soon as the air is warmed by jet exhaust it starts rising, and the heat moves constantly upwards and outwards and cool air mixes in at the bottom, so there is no average 3°C temperature rise on the surface.

But obviously, looking at Figure 2, including warming from all sources there is something like a degree or so of peak temperature increase from the urban heat island at Heathrow.

What is this from? While some is from the acres of hot asphalt runways cooking in the sun, in part it’s from the actual burning of the fuel. Have you ever been caught by the blast from a jumbo jet, even from far away? I have, many times. It smells like kerosene, and it’s warmer than the surrounding air, sometimes much warmer. When one of these blasts hits you, you can easily feel the difference in temperature … and so can the airport thermometer.

With that in mind we can see how desperate the UK Met Office is in their defense of the record. Consider this quote from Dr Mark McCarthy, head of the Met Office’s National Climate Information Centre:

Nor does it make sense to think that a passing breeze could have carried a waft of heat from a nearby aircraft, as Homewood suggests. McCarthy tells Carbon Brief:

“We have checked with [air traffic control] and confirmed that the north runway, which is closest in proximity to our observing station, was being used for landing aircraft. Therefore, landing aircraft would most likely have had idle engines by the time they reached the eastern half of the runway, where our observation station is sited.”

Had passing aircraft generated turbulence, that would help mix the air close to the ground. This would be more likely to lower the air temperature than raise it, McCarthy says.

I fear Dr. McCarthy has not spent enough time out on the tarmac … first, after landing jets do not have “idle engines”. They use their engines to move around the airport, blowing hot air out behind them as they go. And every time they stop, it takes a big blast of hot air to get them moving again. And second, while it is possible for jets to reduce the ground temperature because of the turbulence from their wings, in general, guess what?

Burning about a million gallons (3.4 million litres) of kerosene per day in one location generally does NOT lower the air temperature as McCarthy implies.

Here’s part of the problem. This shows the location of the meteorological station at Heathrow.

Google EarthScreenSnapz001

Figure 3. Location of the meteorological station at Heathrow Airport is shown by the white circle. The large runway across the middle is the “north runway” referred to by Dr. McCarthy in the quote above. Note the jet at the bottom for scale.

As you can see, the met station is about 150 metres (500 feet) from the north runway. The difficulty comes after landing and slowing down, when the jets turn off of the eastern end of the runway by the met station on one of the side taxiways. At times in that process, their jet exhaust will be pointed directly at the temperature measuring station. Indeed, when jets turn off on either of the  two right-hand taxiways in the picture above, their jet exhaust is pointed directly at the met station for the entire trip down the taxiway … and did I mention that the wind was from the south and southeast during the time of the temperature record, blowing from the taxiways towards the met station?

So … did jet exhaust cause the large spike in Heathrow temperatures on 1 July 2015 that created the new record? I’d say:

a) we don’t know, although it certainly seems plausible and winds were in the right direction, and

b) it certainly can’t be ruled out by what the Met Office has shown, but in any case

c) it doesn’t really matter because jet fuel and runway tarmac assuredly warms Heathrow in general, so any Heathrow records are not very reliable or meaningful.

One final thought for you. Heathrow proudly proclaims that from 2012 to 2013 it decreased its CO2 emissions by 11,923 tonnes of CO2. Cue the applause.

However, during the same period, China increased its emission rate by 358,304,399 tonnes/year of CO2. This means that the increase in Chinese CO2 emissions, not the amount of the emissions themselves but the amount of the increase in emissions, is about 40,874 tonnes per hour… which means that all of Heathrow’s proud one-year accomplishment of emission decreases during all of 2012 was wiped out by China in the first 17 minutes after midnight on January 1, 2012.

Dust in the wind …

Regards to all,

w.

As You May Know: If you disagree with someone, please quote the exact words you disagree with so we can all understand the nature of your objection.

Heathrow Airport Details: Over at the Talkshop, tchannon has a good description of the physical layout of the airport here.

Update from the Comments: First, a number of folks mentioned thrust reversers, which I’d forgotten to consider, and the fact that they blow the warm jet exhaust to the sides … in other words towards the met office.

Also, someone talked of the importance of winds. This is very true.

Wind is indeed important, at times crucial. And even if the speed is constant, the direction can be critical. I was going to include the following but the post was getting long. Another example of met office guys not getting out enough.

Now, any swabbie sailor like myself would look at that and say “Yep, that wind is swinging quite a bit”. It looks pretty typical for a wind regime, the wind direction tends to sway from one side to the other once or twice in an hour or so, which this does.

How much is it swinging? Well, it swings from a minimum of 130° (about southeast) to a maximum of 180° (south) during the hour. This is a not insignificant range of no less than fifty degrees.

And the largest rate of swing was a change of fifteen degrees in five minutes … so I’d have to disagree with Dr. McCarthy when he says:

“We’ve looked at wind data and there is no sudden change in wind direction at Heathrow around the time of the record.”

All the best to you all,

w.

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261 thoughts on “Heathrow Hijinks

  1. Howdy Willis
    Correct following “warning” To “warming”. Under the first graph>
    “sense to you that a subsequent solar spike twenty minutes later would lead to no warning at all?”

    • Thanks, Dahlquist, fixed. My motto is, “Perfect is good enough”, any assistance in that direction is always appreciated.
      w.

      • Willis
        A similar very odd spike happened in Brisbane Australia on November 16 2014, famously the day of the G20 Climate summit in that city. The temperature was nowhere near reaching the ‘highly anticipated’ predicted new record (of about 42C) and was hanging in the low-mid 30C’s in the middle of the day and early afternoon but ‘magically’ the temperature shot up in about 20 minutes late in the afternoon to hit about 39C. I was watching it develop that day on the BOM website. I don’t know whether the BOM has the archive for the measurements which were taken that day every 10 min publicly available online (I can’t find them now) but here is the summary for that month and you can note the information it gives for November 16 2014:
        http://www.bom.gov.au/climate/dwo/201411/html/IDCJDW4019.201411.shtml
        In Brisbane, one can get sudden hot gusts from the interior hitting parts of the city while others sections remain 10 degrees cooler. But again an odd coincidence.

      • Another correction Willis, for an otherwise excellent article. As a first nation Briton, a Gaidheal, I would point out that it is not entirely an land of “Anglo-Saxophones”, and that some of us original Brits still survive.

      • Paul Mackey July 20, 2015 at 4:13 am

        Another correction Willis, for an otherwise excellent article. As a first nation Briton, a Gaidheal, I would point out that it is not entirely an land of “Anglo-Saxophones”, and that some of us original Brits still survive.

        Way cool … are you a descendant of the guys who painted themselves blue and buried their dead in wheel-barrows and snorted woad? And just what is “woad” when it is at home, anyhow?
        Enquiring minds want to know …
        w

      • Willis Eschenbach:
        There are many British people whose ancestry includes the Celts and they are mostly in Wales, Scotland and Cornwall (i.e. the ‘Celtic Fringe’).
        They used the indigo dye called woad as a war paint. It was a good war paint because its antibiotic properties reduced fatalities from wounds.
        Woad is made from the woad plant (i.e. isatis tinctoria) and you can obtain more information on woad than you could want from the ‘All About Woad’ web site and its links.
        Richard

    • I was just going to mention that, you beat me to it. Yeah, those screaming jet engines I hear and feel after landing must be “idling.” Does working for the Met office cause a massive abandonment of any logic or common sense, or is that a prerequisite for the job?

      • And consider too that when the wheels hit and the thrust reversers open and the engines spool up to 80% or whatever you ‘re blasting a big cloud of hot air a thousand feet to either side of the aircraft on the landing roll, until the crew decides to close them and taxi off.

      • Here is an interactive view of the met office station at heathrow whereby you can scroll around to see the full extent of the Tarmac and number of jets
        http://weather.gladstonefamily.net/site/search?site=EGLL&Get+information=Get+information&lang=en
        It can be noted the very busy roads and large amount of industrial activity immediately around the perimeter.
        Records have been kept here since 1948 when this was a tiny RAF airfield. Since then it has grown many thousandfold and it is nonsensical to try to claim any records for such a large area of Tarmac together with the related infrsastructure. Most likely a jet caused the increase in heat although it must be said it was very warm in the area for July 1st
        This was due to a heat plume that came up from morocco and Spain for a couple of days. It was not nationwide, here in the southwest it was no more than fairly warm. It was by no means hot.
        Britain itself is only the size of new York state and is one big heat island. The met office take uhi into account in its records but probably not enough. The London area is a huge chunk of uhi in its own right and is commonly four or five degrees warmer than other parts of the country. Heathrow must be a uhi imposed on an uhi.
        Tonyb

      • Concrete runways. Big jets with 300 psi tires tend to sink into asphalt on hot days.
        Thrust reversers are only used at high power during the initial, high speed part of a landing, as they are inefficient at lower speeds. Most airline policies keep them deployed during the entire rollout, but at idle power after the aircraft is slowed. At the higher speeds, the exhaust is swept backwards, so you don’t get much sideways effect beyond the runway edge.
        Twin engine, tail mounted engines deflect exhaust vertically.

    • Yes, most jets pull 70% N1 rotation speed with reverse thrust. That does not equate to 70% of full power, but it is still a great deal of thrust and heat. So if there was a northerly component to the wind it would easily arrive at the met station.
      And the jetblast travels a long way. I was blown over by a 747 manoevering onto a stand on the opposite finger to where I was. And yes, it was hot.

      • A normal reverse of 70% N1 is just under 50% thrust. An 80% N1 max reverse gives well over 50% thrust. There are problems with pulling more thrust, including air reingestion, dust and stone damage, and aircraft vibration.

  2. by an astounding historical coincidence, the UK’s largest airport was built precisely on top of the warmest spot on the island …

    Coincidences, such as this, happen. What are the chances that Lou Gehrig would contract Lou Gehrig’s disease?

    • I am certainly non-expert in the field of airport siting, but intuitively, I would think the sites chosen would tend to be
      1) On high ground
      2) Open to the sky
      So, from #1, I would think the area would generally tend cooler due to higher elevation, but #2 would tend to make it warmer due to lack of shade, yet cooler due to winds. If the surrounding grassland were regularly watered – which seems likely since you wouldn’t want dust clouds – evaporation might tend to make it cooler. No doubt, this list is not comprehensive for all influences.
      All in all, I don’t know how it would all fall out. But, I wouldn’t completely discount the possibility of either a warm or a cool bias.

      • Flatter, and in relation to human habitation, probably trending lower. That’s a big ‘probably’; I can think of many exceptions and even more reasons for exceptions.
        =================

      • It’s easier to live on broken terrain than it is to land planes on it. Hence hills for living, lower, flatter for landing. This is highly speculative, but a fun furrow to follow.
        =====================

      • Easier to build on the flat than the hills, too, though. The numbers exist; let them be run.
        ================

      • Bart
        Heathrow is in flat terrain to the west-south-west of London. I’m pretty sure the average elevation of the area can’t be much more than 20m above MSL (I used to live within a couple of miles of the end of the runway).
        To the west is the M25 London orbital motorway and then semi-rural land (variously grassland, reservoirs and small towns, plus the River Thames), while to the north and south are London suburbs and to the east is London ‘proper’ Other than to the west, the airport perimeter is built up with variously industrial / distribution warehouses and medium rise hotel buildings.
        For Britain, the prevailing wind is westerly or south-westerly, with this being the case for about 90% of the time (hence our strongly Atlantic maritime weather). However, TonyB (Climatereason) makes the good point that on this particular day the south-east of England had southerly to south-easterly winds blowing from the near Continent, bringing unusually hot and dry air up from central France. It was unusually hot for much of England, and on the face of it the temperature record for July was broken in that the Heathrow temperature sensor recorded a higher temperature than has ever previously been recorded in England. The questions are 2 fold:
        1 – Is this record comparing ‘apples and oranges’, in that the temperature sensor at Heathrow is undoubtedly affected by UHI and microsite effects, and doubly so in this instance where the warm air reachin Heathrow had passed over a substantial part of London?
        2 – To some extent, so what? Records are broken occasionally, and we know the weather system for the first couple of days of July was unusual. A very marginal breaking of a high temperature record no more proves climate science than the breaking of a low temperature record disproves it.
        Actually, looking at the ‘month by month’ records, it is interesting how spread record highs are through time – including ties, there are 18 records holders, with 1 in the 1900s, 1 in the 1920s, 6 in the 1940s (3 being different sites on the same day), 1 in the 1950s, 1 in the 1960s, 2 in the 1970s, 1 in the 90s, 3 in the 2000s (2 being different sites on the same day) and 2 in the 2010s so far. Seems a pretty random spread really – maybe a slight hint of more recent records, but that could perhaps be explained by variously UHI and simply having more weather stations measuring temperatures in potentially hot places, or by a gently increasing underlying temperature trend.

  3. “Heat row” is not a standard meteorological station – it cannot be, as the protocol states that such a station shall be surrounded by grassland! Not fuming jet engines and black low-albedo tarmac. The “Heat row” station is just another blunder station, which is good to have for the CAGW-crowd.

  4. The pilot landing aircraft with turbofan engines, immediately they touch down, opens the flaps and moves the covers and guns the engines in order to slow down! Ever landed in one? That reverse thrust is engine power. The mechanics of the operation causes the hot blast to move sideways away from the aircraft.

    • Thanks, Crispin. I hadn’t thought about the jet blast going to the side. Somehow in my head the “thrust reversers” did exactly that, but no, in fact it diverts it generally in a forward-facing cone extending up, down, and to both sides of the engines … and the “down” portion of that has to go somewhere.
      This would set up a sheet of ground level wind, with the sideways wind velocity generally remaining high down to ground level due to the conical nature of the reverser exhaust. The reverser forces jet exhaust into the area between the between the ground and the engines and wings, so it escapes forwards and sideways.
      Well done,
      w.

      • Jet blast raises temps everywhere, ever been on the deck of a Nimitz Class carrier during a scramble? It can get very warm in all directions even when you’re moving at 8 knots into a 6 knot headwind.

      • Unless you’re backing out of a gate with reverse thrust, the forward component of the exhaust is always less than the forward speed of the aircraft, so the exhaust ends up going backwards after it leaves the immediate area of the engine. Somewhat explained by my comment above – 4:17 pm

      • The airport diagram you show gives away a very possible event, There is a fast exit taxiway just after the met observation position. These taxiways are preferred as the aircraft can expedite its exit from the runway rather than be at a slow taxiing speed to take a more right angled exit taking up more runway time. An aircraft that landed long could easily be increasing its reverse thrust to try to slow enough to make its preferred (sometimes declared) exit; right at the time it is upwind of the automated observation station. It would be simple (although behind a paywall for non-government or NATS) to identify landings at the time of the observation and even obtain a replay of the aircraft using the North runway at the time of the observation. It is not in the Met Office interest so they will not do it; but anyone with access to the NATS Heathrow movement recordings could easily obtain the data. I would suspect a long landing by a 4 jet aircraft such as a 747 with extra reverse thrust giving a ‘bubble’ of hot air to the observation station.

      • turboprops don’t have TR but the often change prop orientation and power up to slow down.
        we used to back sf340b out of gate area using props if tugs were all tied up.
        not sure how many turboprops land there though so may not add anything.

    • I had thought of that and dismissed it. There are a lot of planes landing at Heathrow; it’s quite busy.
      If it happened once it would happen all the time.
      My guess is a patch of hot tarmac warmed the air above it and that was stable for a while to allow it to get very hot. Then a plane and a gust of wind pushed it through the Stevenson Screen.
      It was a hot day. The reading was accurate. But the record is obviously meaningless (it’s Heathrow!)
      So I think the real question is why the MET Office don’t just say the record is real and meaningless.

  5. WIllis- after reading almost all of your essays over the past few years, I just wonder if your brain is wired just a little differently. 🙂 As always, entertainingly written and easily understood. Poor Dr. McCarthy wiggling best he can until it blows over, so to speak.

  6. Between 1957 and 2014 the 10 year mean July temperature differential between Heathrow and CET increased by approximately 0.96c.
    July also happens to be the busiest month at Heathrow (in terms of passenger numbers).
    The temperature differential for June (the third busiest month) increased by 0.95c compared with an annual average increase of 0.784c.
    This does not prove the increase in temperature is due to aircraft activity but I struggle to think of another explanation.

  7. Heathrow is always significantly hotter than anywhere nearby at any time of the year. I live about 12 miles away.
    St James – in the heart of London with all of its Urban Heating – is just 14 miles or so as the crow flies from Heathrow airport and on the day in question was more than 1 degC Cooler than Heathrow.
    It is normal for TV weather forecasts to predict London temperatures as 2 and even 3 deg C Higher than the surrounding rural areas.
    The Met office have long appeared to me to be totally committed warmists and propagandists.

    • The Met office have long appeared to me to be totally committed warmists and propagandists … but they pretend not to be.

    • Their town to countryside figures vary by as much as 10°C (clear nights) but they manipulate the data by 0.1°C to allow for UHI effect.
      Now, does that seem to you to be good science?

    • I agree. I have made similar comments in the past, and again on the Heathrow July 1 temperature. Of late the Met Office has increasingly quoted Heathrow or St James’ Park, central London, as the warmest place but both are heat islands. I’ve no doubt in my own mind that the Heathrow temperature on this occasion reflected both heat from the acres of tarmac and jet engines.. This should have been made clear. The Stevenson screen is ill-placed and should be moved well away from the runways and engine exhausts.
      I’m surprised that Dr McCarthy thought that jet engines were idle when the plane landed. The power surge when they turn off the runway is huge with massive gusts of heat.

    • ..and slowing down on landings
      ATC did not tell the MET that the engines would be in idle at that point….the MET made that up
      They would have been in full reverse at that point…….

      • It isn’t as simple as that. Reverse thrust is bad for the engines and used only when necessary, usually on short runways or when the airplane is heavy. On long runways it might enable the pilot to shorten the taxi to the gate but that of course depends on where the gate is relative to the runway.

      • For small aircraft, yes, they will try not to use reverse thrust. But it is not that simple. ATC may want you off at the third exit, because of another an aircraft close behind, so you have to stop faster. Or your allocated stand may be on the east side, and you don’t want to taxi 2 miles in the wrong direction.
        Plus most of the large aircraft will be using reverse most of the time. LHR is not that long, for a 747 or 330.

      • Billy Liar July 18, 2015 at 1:12 pm
        If Clive Best information is correct about the time of the temperature spike a BA 747/400 from SFO landed on the North runway on ‘easterlies’. The BA terminal 5 is to the West of Heathrow, so a reduced roll out would reduce the taxiing considerably. I would expect the aim was to take the fast exit just at the end of the landing zone for westerlies and reverse thrust and braking would be increased to ensure the exit could be made. This would be directly upwind of the observation station. Anyone who has stood at the boundary fence of Heathrow knows that there are occasional warm bursts from the aircraft operating there.
        There are some excellent meteorologists and forecasters working in the Met Office, but their reputation is being sullied by activists desperate to maintain a ‘global warming’ hypothesis that is looking closer to complete falsification with each passing year.

    • Joe Public July 18, 2015 at 12:04 pm
      “Heathrow is the 3rd busiest airport in the world.”
      For passengers yes. For Aircraft no. It is currently the 10th busiest in terms of planes.

  8. I remember a few years ago we had the hottest day ever in Britain – and again it was at Heathrow. I live in West Wales and it amused me because here in Wales it was overcast and there was some slight drizzle. This year it happened again, at Heathrow we had the hottest patch of hot air ever recorded in Britain, and here in Wales, about 200 miles west, we had overcast skies and light rain

  9. “We have checked with [air traffic control] and confirmed that the north runway, which is closest in proximity to our observing station, was being used for landing aircraft. Therefore, landing aircraft would most likely have”…
    been riding their clamshells and buckets the hardest

  10. Willis, another good article, could you please apply to run the Met Office; they are desperately in need of an injection of logic and common sense!

    • @andrew, ‘an injection of logic and common sense!”. Seemingly the two hardest commodities on this planet these days. There are days I just tear my hairs out when I read/ listen/watch the warmist crowds come up with another doozie! This one about Heathrow is mind boggling. And thanks Willis, another Saturday night laugher, I just cannot believe these “academics/scientist can sleep at night, look their family in the eyes and for that matter have the guts to show up for work the next day!.

      • @andrew, ‘an injection of logic and common sense!”. Seemingly the two hardest commodities on this planet these days
        The two rarest commodities these days. There can never have been a period in recent history when so many politicians have been so completely stupid and inept.
        What were once the yhree great powers USA, UK and France are now plague by the three most stupid legislature

  11. Wind speed is important. Sometimes it takes a little breeze to blow away the locally produced heat, so when the wind drops to calm you get a spike in the heat. This is clear in other locations, such as the North Pole.
    I know they work very hard to build the thermometers in such a manner that they are not influenced by sunshine, but up at Faboo (my name for the North Pole Camera Buoy) the buoy itself creates a pool of water on the sea-ice. The melting must be caused by a tiny micro-climate of warm air. Then, on the rare occasions when it is sunny and the wind drops to a dead calm, that micro-climate isn’t blown away and the temperature immediately rises roughly 2° – 3°, and then as soon as even a slight 2 – 4 mph breeze starts back up, the temperature drops back down.
    I don’t see what is so hard about being humble, and simply confessing our manner of collecting temperatures includes the effect of man-made objects. It is downright silly to pretend we have a perfect system that can measure down to hundredths of a degree.
    https://sunriseswansong.wordpress.com/2015/07/12/arctic-sea-ice-breaking-up-is-hard-to-do/

    • Thanks, Caleb. Wind is indeed important, at times crucial. And even if the speed is constant, the direction can be critical. I was going to include the following but the post was getting long. Another example of met office guys not getting out enough.
      https://wattsupwiththat.files.wordpress.com/2015/07/heathrow-winds.png
      Now, any swabbie sailor like myself would look at that and say “Yep, that wind is swinging quite a bit”. It looks pretty typical for a wind regime, the wind direction tends to sway from one side to the other once or twice in an hour or so, which this does.
      How much is it swinging? Well, it swings from a minimum of 130° (about southeast) to a maximum of 180° (south) during the hour. This is a not insignificant range of no less than fifty degrees.
      And the largest rate of swing was a change of fifteen degrees in five minutes … so I’d have to disagree with Dr. McCarthy when he says:

      “We’ve looked at wind data and there is no sudden change in wind direction at Heathrow around the time of the record.”

      I’ll add this to the end of the head post.
      All the best,
      w.

      • Remember the record at Eureka a few years back? Same thing. Change in wind direction caused a short term spike. In that case the local meteorogist pointed it out to his credit.

  12. ‘which means that all of Heathrow’s proud one-year accomplishment of emission decreases during all of 2012 was wiped out by China in the first 17 minutes after midnight on January 1, 2012.’
    The obsession with ‘reducing carbon footprint’ by organisations such as Heathrow and all Government funded establishments, from hospitals to universities, is one of the more ludicrous activities in the UK masquerading as meaningfully reducing the risk of a man made climate Armageddon. The National Health Service, for example, contributes 3% of the UK’s carbon output, which in turn is only 1.5% of global output. Nevertheless, this cash strapped institution is quite pointlessly spending £millions p.a. on reducing its carbon footprint. The lunacy is just mind boggling.

    • A new profession of carbon accounting has been created on the back of all this CAGW nonsense. The reporting requirements for ‘carbon’ imposed on utility companies in the UK have to be seen to be believed.

      • A new profession of carbon accounting has been created on the back of all this CAGW nonsense.
        I sometimes wonder whether that’s the aim – job creation. Same goes for unreliables, inefficiency breeds jobs.

    • The irony is it’s our harnessing of fossil fuels that has permitted this sort of increasingly marginal pursuit and make work programs for boofheads increasingly detached from the means of production and economic scarcity. However there’s the fallacy of composition awaiting us should we all decide to bite the hand that feeds us so well.

  13. Are there no thermometers just outside of the airport area that could be used to check how reliable the Heathrow station data is? I would think they would want to test this just to see how much UHI there is at airports like Heathrow.

      • TonyB has pointed out below that Accuweather seems to be simply echoing Heathrow temperatures and attributing them to he local towns. If so, these figures don’t help – sorry about that.

      • If you had an ounce of brains, you’d wonder about that.
        According to Accuweather, those four towns are IDENTICAL to Heathrow for every day from 28th June to 18 July. Their Junes are identical, too. So, clearly the Heathrow figures are simply pasted over every nearby town. … And Bedford,
        and Huntingdon, and Sawtry – 66 miles North of Heathrow, but Yaxley (6 miles further North) was 5 Celcius cooler!
        Clearly Accuweather temperatures are worthlless.

  14. The higher solar radiation at Heathrow would cause an increase in THE FIRST DERIVATIVE of temp, not an instant rise in temp. Thus, if that was a significant factor, the solar radiation peak would correspond to the temp ramping up. Since it actually ramped down near the end of that radiation peak, the radiation obviously had virtually nothing to do with the temp.
    This is all obvious to any student of differential equations.

    • “This is all obvious to any student of differential equations.”
      Yes, or course. The fact that it is the opposite of what is experienced by anyone who has ever walked across a large paved surface during a hot sunny day is inconsequential compared to what math sophistry can tell us.

      • No, walking across a large paved surface on a hot sunny day would confirm exactly what I wrote. If you “experienced” it at different times of the day, you would notice the temp rising. It’s hotter later in the day.
        Note: I am agreeing with Willis, specifically, this part:
        “They used this graph to claim that it’s the sun, stupid … but the first problem is, according to their graph, about twenty minutes after the peak in temperature, the clouds parted a bit and the solar input jumped up again to nearly as high as it had gone before … but the temperature didn’t change in the slightest. Well, that’s not entirely true.”
        You seem to have copped an attitude because you think I’m disagreeing with him.

      • I suppose I may have missed exactly what you were saying, and hence “copped an attitude”. For that I shall “do you a solid” and apologize.
        I also should have quoted this sentence: “…the radiation obviously had virtually nothing to do with the temp.”, rather than the one I did, because I was mostly opining that the rays of the mid afternoon sunshine on one of the most direct sun angle days of the year almost certainly had some affect on the temperature recorded that day, although almost surely not the only factor.
        I really do not know how to isolate the jet wash component of that recorded temp, on that day and in that place.
        But I do know that I am not sure one has to isolate such a component, in order to be reasonably certain that recording climate data in places with increasing amounts of paving and structures, or any sort of changes in land usage… is absurd. Particularly if the data collected is then used to make any sort of sweeping conclusions about anything other than the effects of urban sprawl.

      • On that we absolutely agree. Heathrow is a ridiculous place to measure temperature in the first place. The bad siting of thermometers all over the US has been Anthony’s signature issue. He should win major award for it , but who are we kidding?
        Meanwhile, the time scale in Figure 1 above is in minutes. That highlights the absurdity of the whole thing.

  15. Thanks, Willis, as always, for your common-sense analysis.
    Here, as elsewhere, one senses a whiff of desperation, as Nature fails to stick to the CAGW Party Line….

  16. Willis, just a heads up….might not mean much…but a 1/10th of a degree doesn’t mean much anyway
    They just resurfaced the northern runway and tarmac…makes it blacker/hotter…..last winter
    …this was it’s first summer resurfaced

    • “We have checked with [air traffic control] and confirmed that the north runway, which is closest in proximity to our observing station”…and tarmac

      • Tarmac? Black asphalt?
        Tarmac is crushed rock and tar. Major commercial airports are not likely to be resurfacing runways with either tarmac or black asphalt unless those runways are for lightweight aircraft only. In Alaska, asphalt supports 737s. But an asphalt runway isn’t likely to survive many takeoffs of 970,000lb 747s.
        Resurfacing often involves use of Portland Cement Concrete (PCC). One form of PCC is concrete mixed with fly ash from coal-burning power plants. Coal ash increases both strength and weather resistance.

      • verdeviewer July 18, 2015 at 3:38 pm
        Tarmac? Yes:
        Heathrow’s Southern Runway resurfacing in timelapse

      • Stephan Skinner:
        Where in the video does it say that the runway is being resurfaced with tarmac?
        I see a earlier coating being removed and replaced. Do you think cool music in a video made to promote the contractor who did the work makes everything good?

      • Looks like an asphalt lift. The first trucks sprayed a tack coat, then the big dump trucks came in and poured hot asphalt mix into the paver. You can see steam coming off, so it isn’t concrete.

      • It is true in some places. Here in Florida, and most places I can recall here on the East Coast where I do most of my air travel, airports are all concrete.
        But even in places where asphalt is used, it is often applied over a concrete foundation. This is how streets are constructed in Philly, and have been for many years.
        Obviously there are cost and performance tradeoffs among the various surfaces, and which surface is used is dictated by some calculation of how best to optimize some characteristics rather than others. Examples likely include durability under various conditions, installation and maintenance costs, surface characteristics including friction, rolling resistance, and traction, and how the expected range of weather conditions may affect each of these characteristics.

      • verdeviewer July 18, 2015 at 7:28 pm
        “Where in the video does it say that the runway is being resurfaced with tarmac?”
        I think you already have your response. Resurfacing takes place during the short time the airfield closes. As you can see from the video that the machines are laying a tarmac/bitumin composition whatever and this runway is ready to use as soon as all the equipment is off. Concrete takes days to set and is not flexible. I understand there to be several layers and as the original WWII runways and taxiways were concrete there might be some concrete buried underneath the surface layers of tarmac (I don’t know). However, the loads today on these surfaces are so far in excess of anything that a WWII bomber could give that I would guess these runways are more complex (than concrete) and deeper than the originals.
        Anyway, nice comments about the music and its funny because when I found this video it was the music that convinced me. Yes, in fact cool music does make everything good.

      • I sit corrected. They’re replacing asphalt. As can be seen with Google Earth, both runways are topped with asphalt. (Aprons are concrete. Can’t leave an A360 sitting on asphalt.)
        Construction may be similar to the proposed third runway:
        300mm aggregate topped with 500mm concrete topped with 400mm asphalt.
        Runways at SEA, SFO, BUR, LAX, PHX, and JFK in the US and Orly in France are concrete.
        SEA is replacing an old runway this year with concrete panels underlayed with asphalt. Estimated life: 40 years. The concrete runway it replaces had an estimated life of 20 years when it was built in 1969. Since 1995, about 15% of its concrete panels have been replaced.
        The video soundtrack really was appropriate. Did you notice it ended with what sounded like a puking frog? I imagined the smell!
        Yes, it seems the media refers to any pavement on which an aircraft sits as “tarmac.” The media is good at mislabeling things. All it takes is one lousy article to create a terminological consensus.

  17. It’s all just patent nonsense of the sort the Met Office Warmistas have been peddling since that venerable institution was hijacked by politicized “scientists”.
    The entire LHR met station data set is useless – except as proof of the impacts of UHI and jet engines on local climate.
    This announcement by the Met Office was purely “politically” motivates – it’s all part of the run-up to Paris later this year. 2015 has to be a record year, the hottest evaahhhhh!
    I call BS.

  18. Anyone into their military history looking at that list of other sites breaking records that day may recognise a couple of Battle of Britain airfields.

  19. Does Heathrow have any cameras of the runway area whose recordings might be available? There might also be some amateur videos, but those will be hard to locate… unless there are popular viewing spots that one could visit on the same day of the week, and ask around.

  20. An ounce of calculation (Willis), dispels a ton of hot, defensive windbaggery (McCarthy and UK met office)

  21. As a matter of interest, being an RAF brat, some of those stations leaped out at me: Wittering, Cranwell, Markham and Waddington are all operating Rpyal Air Force stations – some shared with the USAF (flight operations, that is.). Manston is a former RAF station, now a civil airport though not, currently, servicing large aircraft.

  22. Also in UK Met Office list of record temperature locations for July 1st are:
    Wittering (Royal Air Force (RAF) base – nice tarmac and planes etc.)
    Cranwell (RAF training base – nice tarmac and planes etc.)
    Manston (airport – formerly RAF Manston – nice tarmac and planes etc )
    Marham (RAF base – nice tarmac and planes etc. regularly achieves high records)
    Waddington (RAF base – nice tarmac…. you get the picture by now)
    Like Willis I have the choice to believe that these location were fortuitously built in five of the hottest spots in the UK, or that acres of tarmac and jet exhaust have more to do with it.
    I favour the latter explanation.

    • Andy, I’m with you…
      MET likes to claim all things are the same….Heathrow just resurfaced that north runway and tarmac with brand new black asphalt….check the link I Posted above this

      • Quick caveat – Waddington’s runway is in re-build just now, so not much traffic apart from dump trucks, etc. But it has been exceptionally warm in the UK East Midlands on several days this summer.

      • In which case the Waddington station may well have large dump trucks driving straight past it on a regular basis at the moment!

    • Quite so. And then, having picked your overheated location, you just have to apply the usual sleight of hand: locate the hottest minute and declare the hottest day.

  23. There are two hot spots in this part of Universe often quoted as the highest temperature record holders of the day, Heathrow airport and Wisley Gardens in Surrey. I am well familiar with both. Heathrow airport can be discounted for obvious reasons, so to some extent RHS Wisley due to its location near the A3 and M25 junction, the two busiest roads in the SE England.

  24. I suspect that you are very generous in assuming 30% of the fuel energy went into work instead of heat. My guess would be that the only energy that left that immediate area left in kinetic energy in the aircraft due to an increase in speed and potential energy due to change in altitude. All of the rest would be turbulence which would quickly be dissipated into heat. While I am not usually shy about making wild guesses, I would not want to even attempt an estimate of kinetic and potential energy of the departing aircraft. Also consider that arriving aircraft may also have some kinetic and potential energy to dissipate. I can’t think of anywhere else it can go except to turbulence and then to heat unless you want to consider how much might actually be accounted for in the deterioration of the tires during braking. The energy dissipated by the brakes also goes directly to heat, but that would take a number of minutes to show up in the atmosphere.

    • The energy dissipated during the mechanical braking of aircraft arriving at Heathrow is not that much relative to that released from burning fuel. We can easily estimate its order-of-magnitude by assuming an Airbus A320-200 represents a good average of aircraft size between the jumbos and smaller “regional” jets using Heathrow. My apologies, but I’m going to use English units (in honor of our British friends . . . even though they’ve “gone metric”) but will give metric units as well for the bottom line energy dissipation. The A320-200 has a maximum zero-fuel weight of about 138,000 lbm and an operating empty weight of about 94,000 lbm . . . let’s assume with full passenger load, luggage and cargo, and 25% or less fuel load, we have about 140,000 lbm landing. This aircraft has a typical landing speed in the range of 150-160 mph, so let’s assume 155 mph, or 227 ft/sec. This is equivalent to a single A320-200 landing kinetic energy of 1.12E+8 ft-lbf (152 MJ). It is difficult to find information on the fraction of aircraft landing breaking actually performed just by thrust reversers—and note that they are not used on all aircraft—but one source indicates they might provide something in the range of 10-15% of total breaking under normal conditions . . . let’s conservatively use 15%. In 2014, Heathrow had a daily average of 1,290 “air transport movements”. So, these last two figures combine to yield an estimated total mechanical breaking energy dissipation of 1.23E+11 ft-lbf (1.67E+11 joules) per day. Thus, in comparison to to the above article’s estimate of “… 6.13E+13 joules per day, of heat solely from the burning of the fuel”, aircraft landing breaking heat is a small very small fraction.

  25. If the thermometer is primarily used to report airfield conditions it is better if it reports the highest temperature at the airport for pilots to calculate their safety margins. Hot air is less dense and that affects lift and thrust.. It is not therefore suitable as a met station. IF the met office is using it as input to temperature records, that’s just plain wrong. You wouldn’t do it except as a means of deception. Which they know well, better than this Oxfordshire housewife.

    • Nope, hot conditions require a longer takeoff run. Air density is the most important factor.

      • When the air is less dense you can consider the runway as shortened. Those slats and elaborate flaps would be less needed with denser air. It is true in cruise you want less dense air up to a point. Most pilots operating near an airport want the ability to go upwards quickly. Dense air helps with that.

    • As a child, you never experienced walking barefoot in the summer on a paved road or sidewalk (of any material), dirt, and grass? How sad. Don’t let colors fool you. Black tarred roads and white sand would both burn far worse than brown dirt. More significantly, you could feel the heat radiating up from the roads and the sand, but not the dirt.

    • I suppose it is never obvious enough to leave off the /sarc tag.
      I spend a lot of time walking around barefoot. Always have, since a lad.
      I have burned my feet plenty of times. I can recall walking home from the swim club in Philly in summer in bare feet, and halfway across one of the blacktop streets having to run to a white stripe on the road to avoid third degree burns. The pebble-topped concrete of Center City sidewalks is almost never too hot to walk on, although newer and flatter concrete sometimes was. The beaches from Seaside Heights to Cape May were often hot enough to burn the feet, but relief could be had by stopping and pushing aside the top few inches to reach the cooler sand beneath. And the really hot sand was away from the water where it was very dry…below the high tide line it sometimes got hot but not scorchingly so.
      One place I never ever burned my feet no matter how hot it was, was on grass. Or anywhere near the canopy of a tree…even if the canopy extended over the blacktop, and was only dappled and shifting shade…it made all the difference.
      Growing plants for a living for many years, and being an avid gardener, I have had many occasions to note the very striking and dramatic microclimates created by structures, paved surfaces, and trees.
      Even a small slab of a patio in the middle of a grassy area can be several degrees different from nearby areas. And even a single tree can have a very large cooling affect. Having many trees in an area obviously cool the area.
      Dramatic effects from a small structure or paved surface imply larger such effects from large areas of pavement and structures.
      Anytime structures are added and/or new paved surfaces are installed, some other surface must be eliminated, and whether it was grass, trees, bushes and hedges, or some combination of those, there is less cooling and more heat retention in that area. And I am not really sure about the UK, but here in the US, air conditioning units are becoming larger and more commonplace. Large buildings are never constructed with windows that open anymore…they are all climate controlled year round. This adds even more heat to the exterior space around structures. So add that in to the mix as airport traffic increases year by year, and more structures are added near these centers of commerce, shipping, and transportation.

      • My apologies that I did not recognize the sarcasm, but I have read far worse from people who were dead serious. In many cases, hard data, often derived from experiences in everyday life, contradicted a warmist’s position. That never seemed to faze them, though.

  26. that heat is traveling some distance.
    “The magnitude of the blast to be expected, and updated blast distance figures are needed to fully understand the nature of the danger from today’s jet aircraft. For instance, for a large aircraft like a Boeing 777 taking off, the blast velocity out at about 2,200 feet can still reach 35 MPH”
    https://www.copanational.org/PilotsPrimerDec07.cfm

  27. Out of interest, In fig 2, Wittering, Cranwell, Manston, Marham, Waddington and Bradford are all airstrips. The first 4 are active RAF airfields, Manston is inactive, but the met. array is close to the tower, Bradford is a civil airport. I can’t speak for the other sites.

    • Fascinating graph. The whole peak temp lasts a few minutes, and the excursion from the linearly decreasing trend is less than 30 minutes. This is why I simply can’t get my head around the practice (obsession?) with averaging high and low temperatures to get some meaningful information about a day’s heat content. Yes, it was hot for 20 minutes–what about the rest of the hour, day, week, month?
      When observations were limited by the ability of a human to look at a thermometer, yielding sparse data, this sort of averaging made sense. But with continuous recording as above generating a complete time series, it’s pretty meaningless to focus on highs and lows. There has to be a better way of describing the heat content. I’ve been impressed, for example, by the general observation of higher low temperatures while high temps are essentially unchanged in much of the record. An averaged high and low dispenses with even that small detail present in the information.
      Nutty to get excited about one station’s 20 minutes of fame.

  28. I think I remember reading somewhere quite recently that Heathrow only began measuring the temperature in 1948. If this is correct then the hottest day ever should read ‘since 1948’ Can anyone confirm this?
    Tony Windsor

  29. Couple of points. Most of the met stations quoted here are airports. But mostly minor or RAF fields, so less traffic and therefore less heat.
    As to your heat calculations, please remember that a jet will burn the most when it is not moving, and burns less and less as it get some airspeed, which supercharges the engine.
    So a 747 on take off will be burning an increadible 100 tonnes per hour, during the take-off roll. Obviously this will reduce down to something like 28 tonnes an hour in the cruise. So the greatest fuel burn, is not up to 3,000 ft — it is on the runway itself.
    Ralph

    • Silver ralph July 18, 2015 at 2:14 pm
      “So a 747 on take off will be burning an increadible 100 tonnes per hour, during the take-off roll. Obviously this will reduce down to something like 28 tonnes an hour in the cruise. ”
      Are you sure? They only need around 90 tonnes to get across the Atlantic so at the rates above they would be out of fuel half way across!
      [Initial Take-off acceleration is only a few seconds of the entire takeoff roll-liftoff-gain altitude, which is only one-two-6 minutes of the entire takeoff-then-get-to-flight-altitude part of the flight. .mod]

      • Yes, but 28 tonnes an hour in the cruise for a 7 hour flight to JFK is 196 tonnes, and they only take around 90. I think cruise must be closer to 12/13 tonnes per hour, otherwise at that fuel burn rate 747 would require over 350 tonnes of fuel for its max range flights!

      • Sorry, I think I have a pound-kilo error.
        Max tankage on the 747-400 is 173 metric tonnes at an s.g. of 0.80.
        In the cruise, the fuel burn will reduce from about 12 t/hr to 10 t/hr
        The large increase in fuel burn on take-off is only for a few minutes, and is normally about 4x cruise. This would equate to about 45 t/hr on the take-off roll. Once the aircraft gets some supercharging speed, the burn quickly comes down to half that.

  30. “They use their engines to move around the airport, blowing hot air out behind them as they go”
    There’s been quite a bit of work done on trying to reduce the use of engines during taxying – fuel costs being the main concern. Employing more tugs to take planes to and from the runway is one proposal, but this will obviously cost the airports a lot of money. There may well be other reasons – extra taxiways to enable the tugs to move around – in addition. Electric motors to drive the aircraft’s wheels is the other method, but this adds weight and complexity, and needs the APU to power them, when it might not otherwise be running. But in either case there is the risk of a plane getting to the departure point (with a long queue behind) and then finding a problem with an engine, which would normally have been discovered when the plane was being “pushed back” from the stand. Also, this means the engines may barely have time to get properly warmed up before being asked to provide take-off thrust. I believe some airlines now shut one engine down, as soon as they reach their runway turn off, but this is dependent on knowing which route they will be taking to the stand. Differential thrust is commonly used whilst taxying, and turning away from a “dead engine” can be difficult at low speeds. I doubt that any of this is likely to take place at an extremely busy airport like Heathrow – they simply can’t take the risk of disruption with so many aircraft moving about at the same time.

  31. I think you guys have totally taken your eye off the ball….
    You’re coming up with all kinds of reasons to explain the “spike”….but the only reason you are is because the spike is a record…
    …go after the record
    They repave this airport about every 10 years….
    The south runway and it’s parts were paved in new asphalt winter of 2013…summer of 2014 was it’s first summer.
    The north runway and all of it’s parts were repaved by the winter of 2014….summer of 2015 was it’s first summer
    Summer of 2015 was the first summer that the entire airport has had new black asphalt.
    If all that new asphalt only raised the temp around a 1/2 degree….there would be no record at all.

    • It is important not only to debunk the spike, but also the base-line temperature. Other things to look into:
      -Have the terminal buildings been re-fitted recently with more powerful air conditioning?
      -Has air traffic increased over time?
      -Has there been any changes to the general pattern of ground movements?
      -Are there any other large electric motors in the vicinity?
      -Has the vegetation cover changed (type, quality etc)?
      -Most runways were widened for the introduction of the A380 in around 2005, was this the case at LHR?

      • As Latitude showed earlier (by graph) the “spike” lasts about 20 minutes. Doesn’t seem right it would be from a short blast from a jet engine. Also from Latitude’s graph there are many short period changes of +/- 0.5 degrees suggesting the temperature station does not have a long thermal memory.
        We took some friends to the Canadian side of Niagara Falls recently. Near the dinosaur mini-golf there is a massive volcano that “erupts” in a fire-ball every few minutes. The fire goes straight up but you can instantly feel the intense heat on your skin. The heat is gone as quickly as the fire show ends.
        If the temperature measuring equipment set up at Heathrow takes 20 minutes to re-equilibrate after a jet goes by then we shouldn’t even be analysing those records.

    • The increase in the 10 year mean difference between Heathrow and CET is 0.96c but averages smooth out the differences. Individual monthly differences (let alone daily or hourly) can be much higher.
      The June 2015 mean for Heathrow was 16.8c, whereas CET was 14c, that’s a difference of 2.8c compared to a difference for June 1948 of 1.2c, an increase of 1.6c.
      Whichever way you look at it, something is increasing the temperatures at Heathrow relative to CET.

  32. Don’t forget the burning rubber and hot brakes caused by landings.
    Also, I would imagine quite a lot of aircraft parked at the terminals/remote stands would be running APUs trying to keep their cabins cool.

  33. The other issue here is the transient response of the modern thermometers which produces a bias towards recording spikes in temperature compared to mercury thermometers.

  34. Willis, you are a genius! But even geniuseseses…make minor mistakes at time. 30% converted “mechanically”. My my, WHAT pre-tell do you think happens to that “mechanical” energy? Yep, it turns into HEAT. Thus the energy released in the local area by the aircraft is ALL expressed as air heating.

    • Rather than leave it at the airport, I think the airplanes take that mechanical energy with them.

      • Planes carry stuff (passengers, cargo) from one place to another and then back. They tend to be not moving relative to the Earth when passengers come in and out (which means they are actually moving wrt to Earth center of mass, but then they return to the original place).
        Overall, they dissipate as heat most of chemical energy they consume (but they also use some energy to lift fuel molecule from airports to 30,000 feet where the fuel atoms are thrown away as CO2 and H2O and other stuff).
        The question is “how much is dissipated near airports?”

  35. “30% of the energy is used to produce mechanical work, with the rest lost as heat.”
    Yes and no; the mechanical energy is used to accelerate, lift, and move through the air at constant speed. The movement creates drag. The drag creates heat.
    Planes use fuel to get kinetic energy, and cross the 3000 feet ceiling with kinetic energy, but other planes cross the same ceiling with kinetic energy and then almost stop on the runway, turning this kinetic into heat through brakes and drag (with the help of spoilers). We would have to compare the speed of a plane at 3000 feet during takeoff and landing.
    Of course, planes use fuel to generate lift and go from 0 feet to 3000 feet, but the same planes went the other way (no plane is made or destroyed in the airport). The difference is that of course planes carry more fuel when they do up, so you would have to account for the fuel consumption during the whole above 3000 feet flight. This difference means the planes accumulate more potential energy when they go up than they recover when going down. Also, they have more kinetic energy at the same speed during takeoff.
    I would guess most of the mechanical energy produced below 3000 feet is turned into below 3000 feet heat. Some is turned into above 3000 feet heat.

  36. The other thing that would be nice to know, is how their thermometer reacts to transients. If the sensor recieved a short hot burst every five minutes, for a whole hour, would it record a series of spikes, or would it just average them out into one long temperature increase?
    So can the Met Office actually identify a jet-blast spike, or not??

  37. I don’t think those other weather stations provided are the greatest “comparison stations”
    You can view them all using this tool, google maps, google images, and bing maps.
    https://badc.nerc.ac.uk/search/midas_stations/
    Here is the top half, not to confidence inspiring.
    Wittering, active since 1955 and at an AIRPORT.
    St James Park: active since 1903, park in DOWNTOWN LONDON.
    Cranwell since 1917. At an AIRPORT. Next to a road and a runway.
    Nottingham (watnall) since 1941. Seems like it was rural at one time and is now surrounded by lots of development and asphalt. Next to a PARKING LOT.
    Manston. since 1928. At an AIRPORT. It’s in a field situated between the runway and a road. Also, its on a peninsula that juts into the english channel.
    Sutton(bonnington) since 1900, right next next to a road, but in a big field. I am not sure though. there is a nearby university, airport and nuclear powerplant.
    Stonyhurst is visible in bing maps and not in google maps. It is possible that it MOVED recently.

  38. Can someone tell me why, with all their massive funding, Met has never set up a system of pristine weather stations.
    The US did it in 2005, (and that system shows cooling), and the UK is much smaller.
    Don’t they want “clean” data ?
    Is it that they knew they would need these dodgy airport and inner city weather stations to actually create some warming?

  39. >>believe some airlines now shut one engine down,
    >>as soon as they reach their runway turn off,
    Yeah, some brain-dead flight managers insist on this. Yes, they save 20kg of fuel each flight, but they also scrub out a $4,000 set of nosewheel tyres in half the normal time. Yippooo, what a stupid victory.
    >>30% converted to mechanical….
    >>what happens to that mechanical energy
    Actually, Willis is right. The ‘mechanical energy’ becomes kinetic energy and potential energy. If this energy is released back to the environment as heat, it will be in JFK or DCA, not LHR.
    Ralph

  40. An aircraft going from stationary on the ground to 170 knots and 1000 feet above ground level 60 seconds later seem like a lot of work/heat. On landing all that energy is dissipated with work/heat. These acceleration/decelerations and height changes would seem to create additional heat.

  41. >>Stonyhurst is visible in bing maps .
    >>It is possible that it MOVED recently.
    Stonyhurst is one of the few good monitoring stations – an old monastery and now a college. It replaced Ringway (ie Manchester International Airport) a few years back, as a part of the CET temperature record.
    Stonyhurst is famed for having the oldest temperature record in the world.
    Ralph

    • There are 2 pictures of stonyhurst one from google earth and one from bing. I think the station moved, since it doesn’t show up in the google picture.

    • I could be wrong. I just have a bad image from google maps that doesn’t seem to show the station.

  42. If you really wanted to find out the impact you’d scatter 40 or 50 thermometers around LHR and the mile or so around it, even just for three months, sampling no less than every five seconds, and plot the anomalies against location and takeoff/landing activity.
    Based on commodity Arduino-grade microcontrollers these things ought to cost $125 each, and I’d postulate that you’ll see enormous fluctuations between locations and, at certain locations, even between samples on occasion.

  43. Very good post, and some great comments. Paul Homewood was on this, Christopher Booker put it into the MSM, and thanks to Judith you have boiled it down in a nice figuration. The UK Met is revealed to be an incompetent PR engine. Another hole below the CAGW ship of state waterline.

  44. Aircraft Plumes
    Detecting hot engine plume temperature

    As you can see in the citation below, the hot engine plume ranges from a temperature of 1,000 degrees Fahrenheit near the engine nozzle to a temperature of 100 degrees Fahrenheit at 100 feet away from the aircraft. This large moving heat source should be easily detectable with today’s sensitive IR sensors. The hot plume cone is continuous and is “carried” by the aircraft.
    ———-
    http://www.0x4d.net/files/AF1/R11 Segment 11.pdf (page 51)

  45. I love it how you can always come here for a good laugh. I suppose it’s unusual for Heathrow to have “jet exhaust and wind changes,” and so when they had that on one day, it nullifies a temperature record. The fact that several other temperature records were set in the UK that day supports the record reading at Heathrow. Obviously an airport has higher temp. readings than surrounding countryside.

    • Barry, so your contention is that if a jet airplane happens to be parked testing its engine, and it drives the temperature sensor up to a new record, that record is just as valid as at a pristine station?
      I’m sorry, but if as you say you came here for “a good laugh”, today the “good laugh” is your curious claim that jet engines are good method for setting valid temperature records …
      w.

  46. Is your calculation of cubic meters of air above Heathrow correct?
    1227 * 10,000 * 914 = 1.12E+10 m³ (You show 1.12E+12 m³)
    Cheers,
    Mark
    *****************************

    • Calculated correctly in the spreadsheet, but written wrong in the head post. I’ve corrected it.
      Thanks,
      w.

      • An easy mistake when you try to include units from metric and imperial systems in your measurements. Wasn’t there a space probe which went off course for the same reasons?
        1200 hectares up to 3000 feet, indeed!
        At least you didn’t convert the joules to British thermal units.

  47. Besides jet exhaust, consider that the entire facility—including the aircraft—must be air-conditioned. How much electricity is used for indoor cooling on hot days? How much heat is dissipated outdoors as a result?
    Increased use of air conditioning increases the likelihood of local high temperature records.

  48. One must ask whether the Met office believes in the correctness of homogenization, or not. Homogenization would remove this spike, so that it wouldn’t “matter”. If it matters, homogenization isn’t a good idea…

    • Homogenization might remove the spike present on the day in question, but it would not remove the evidence-based conclusion that the Heathrow met station is situation in an “urban heat island” and therefore it’s data is not to be considered as reflecting the “local” climate, let alone that for a larger part of England.

    • Homogenization as practised by the warmists would ensure that every other temp station within 500 miles of LHR were adjusted up to match LHR!!!

  49. There is a site called http://www.flightradar24.com that automatically tracks commercial aircraft through a network of volunteers. They might have actual data of what types of aircraft landed on that runway over the time period together with what taxiways they used.

    • The data is available for Heathrow and Gatwick (London’s second airport) there is an “official” site with downloadable data. I have no idea what most of it is but it does include plane type time of day and, I think, flight number.
      http://www.lhr-lgw.co.uk/

  50. the “hottest July day ever recorded” still pops up on many BBC programs.
    last nite at the cricket (the Ashes, England vs Australia at Lords), with fielders wearing heavy sweaters, someone bought it up in the commentary, & i heard it later in another non-weather/climate radio program. no MSM has done more for the one-hour record than BBC, which began the propaganda on 30 June:
    30 June: BBC: In Pictures: Heatwave hits Britain
    Tuesday has been the hottest day of the year so far, with temperatures of 29.1C recorded at **Heathrow Airport.
    It is expected to be even hotter on Wednesday, but the sweltering conditions have led to health warnings and train companies have cancelled services amid warnings the tracks could buckle in the heat.
    Wednesday’s temperatures could set a new record for July – which stands at 36.5C recorded at Wisley in Surrey in 2006…
    http://www.bbc.com/news/33330171
    the next one was about the Tuesday’s temp (as above) but was rewritten for Wed’s temp:
    Hottest July day ever recorded in England
    BBC News-30 Jun 2015
    as Andy wrote in the comments, other dodgy locations also allegedly had record temps on 1 July but, in the following BBC attempt to convey that, you will NOT find any mention whatsoever as to where these “many places” were:
    2 July: BBC: In pictures: Lightning and hail storms across northern England
    Storms have swept across northern England in the wake of what for MANY PLACES was the hottest July day on record in the UK…
    http://www.bbc.com/news/uk-england-33360867
    THE FOLLOWING DOESN’T ACCOUNT FOR THE CONTINUING, CASUAL MENTIONS ON AIR, THE TWEETS OR THE FB ENTRIES, ETC.
    WHEN BBC WANTS TO MAKE AN IMPRESSION OR CREATE A CAGW MEME, THEY ARE THE MASTERS OF PROPAGANDA:
    Thousands in north-east England without power after storms
    BBC News-2 Jul 2015
    Up to 40,000 properties in the north-east of England were left without power after violent storms struck on the hottest day of the year so far
    Henley Regatta rowers suffer ‘mysterious melting oars’
    BBC News-2 Jul 2015
    It came as the UK saw the hottest July day on record
    Syria air-strike plan, Greece latest and ‘Goldfinger murder’
    BBC News-1 Jul 2015
    By Andy Sully BBC News …. Yesterday was the hottest July day since records began
    Heatwave hits Royal Norfolk Show in Norwich
    BBC News-1 Jul 2015
    Five people have been taken to hospital from the Royal Norfolk Show on the hottest July day on record
    Asia and Australia’s advice to heatwave-hit UK
    BBC News-2 Jul 2015
    England has seen its hottest July day in history
    Massive lightning storms hit UK
    BBC News-2 Jul 2015
    Yesterday was the hottest July day on record
    UK heatwave: July’s hottest day on record – BBC News
    Jul 1, 2015 – The UK has seen the hottest July day on record,
    UK cools off on hottest July day – BBC News
    Jul 1, 2015 – People across the UK take advantage of the hottest July day on record.
    In pictures: UK’s hottest July day on record
    BBC News-1 Jul 2015
    Wednesday saw the highest temperature for a July day recorded in the UK, with the thermometer hitting 36.7C (98F) at Heathrow airport.
    In pictures: Looking back on the hottest July day
    BBC News-1 Jul 2015

    • This reminds me that Germany’s record high temperature was “shattered” by 0.1° before the “record heat wave” morphed into an unusual July frost.

  51. It would interesting to have a second weather station at Heathrow, well away from tarmac and well away from the one referred to in Willis’s article.

    • The closest station to Heathrow in the GHCND network is Lyneham, 66 miles east. Here’s a comparison in °F:
      June-July
      29, 30, 1, 2, 3
      Heathrow
      79, 87, 98, 79, 81
      Lyneham
      74, 83, 90, 70, 80

      • Oops, sorry, Lyneham is 66 miles west of Heathrow. But there is a station at Manston about 60 miles east. Here’s the temperature record there.
        June-July
        29, 30, 1, 2, 3
        75, 78, 92, 78, 71
        It really doesn’t look like wind-directed jet exhaust at Heathrow was a significant factor in the record high.

      • Lyneham being west should be hotter. Westerly wind blowing the UHI of London across west London end the countryside beyond.

      • >>Westerly wind blowing the UHI of London across west
        >>London end the countryside beyond
        A westerly wind blows the heat to the east.

    • It would still be completely surrounded by urban buildup with non-stop traffic, and useless as a source of accurate temperature data.
      If the MET actually cared about accurate temperature data, they’d have dropped Heathrow years ago.

      • Regardless of local buildup, Heathrow’s records would still be useful if it weren’t for the fact that they are woefully incomplete. They cover less than 80% of the last 67 years.

  52. Is it not necessary to consider the changes to the basic background heat emitted by the airport, Heathrow has in recent years undergone a huge enlargement. The completion of T5A,T5B and T5C Terminals, the construction of many thousands of square meters of new taxiways the service these terminals ( all the taxiways being constructed of 457mm thick concrete).
    At the same time a new energy centre and car parking facilities (constructed of concrete) were added to service the new T5 expansion along with a new access roads and roundabouts which were added for access to the terminals from the M25.
    A new underground rail link and a new transit railway to connect the new terminals were also added, Terminal 2 has been expanded and a new energy centre built to service its needs.
    If the background heat output from the airport goes up then the same solar input into the area as occurred in previous years will cause higher temperatures in the area, will it not?

  53. Best to leave the operation of the controls, in the hands of a certified pilot.
    Assuming you got one handy 🙂

  54. If solar radiation and the temperature were in phase with a short timescale then I would for a poor (or poorly maintained) weather station, not properly shielded from solar radiation and resulting in solar loading.

    • This phenomenon can change, depending on the local geometry of the weather station—for example, is the sun shaded from the weather station at certain times of the day?

  55. “by an astounding historical coincidence, the UK’s largest airport was built precisely on top of the warmest spot on the island”,;
    Fig 2 is not a list of the hottest places in UK; just those which set a record for the location. I looked up some July 1 temps on Accuweather
    Reading 98°F
    Windsor 98°F
    Aylesbury 98°F
    No jet engines there.

    • Nick Stokes July 18, 2015 at 5:50 pm Edit

      “by an astounding historical coincidence, the UK’s largest airport was built precisely on top of the warmest spot on the island”

      Fig 2 is not a list of the hottest places in UK; just those which set a record for the location. I looked up some July 1 temps on Accuweather
      Reading 98°F
      Windsor 98°F
      Aylesbury 98°F
      No jet engines there.

      Gosh, Nick, you mean to tell us that the first of July was hot around the UK? How brilliant of you to figure that out on your own! … Oh … wait … that’s what I said in the SECOND SENTENCE OF THE HEAD POST, vis:

      It appears that the first of July was hot in the UK, and among others the airport at Heathrow set a record high temperature for the date

      Or perhaps your brilliant insight was that Figure 2 was not a list of the hottest spots, just those that set records … no, wait, I said that as well in the caption to the figure …
      Then again, maybe your blinding revelation was that you can get hot surface air temperatures without using jet engines and you just wanted to share that with us. If that’s your message, thanks, couldn’t have known that about jet engines without you.
      In any case, you’ve definitely proven that you didn’t read the underlying cited document from the Met Office “Carbon Sense” blog, which states (emphasis mine):

      Record high
      On Wednesday 1 July, a thermometer at Heathrow recorded 36.7C, the highest temperature anywhere in the UK that day.

      Heathrow had the highest temperature anywhere in the UK that day … who knew?
      Oh, wait … I knew, and you didn’t. That’s why I called it “the warmest spot on the island”.
      Thanks for playing, though. Vanessa, what gifts do we have for Nick and the other the unsuccessful contestants?
      w.
      PS—Nick, on a more serious note, I fear I don’t take you seriously, for a simple reason. Far too often you pop up with what are meaningless objections, perhaps just to have the pleasure of reading your own words.
      Now, I suspect that underneath you’re a fairly intelligent guy, but you’re wasting your talents by acting like some demented sniper, taking useless potshots in a vain attempt to damage a target far too distant for you to hit.
      I would like to take you seriously. However, the people I take seriously generally are those trying to move the discussion forwards, not backwards. The people I listen to add to the conversation, rather than trying as you do to cause damage.
      Just saying … I’d prefer not to have to wince whenever I see your name, and I’d love to see you contribute to rather than detract from the conversation.

      • @Willis: “Gosh, Nick”,
        Willis, I guess you are being kind on a Saturday night, And thanks for the report btw as an observer I know how even the slightest variance can influence the temp readings, even running a sprinkler 20-30 feet away (for just a few minutes) from a screen can change the reading by a substantial margin. It would make the MET office have a “cow”. ( sorry me lawn isn’t big enough for a 747 just yet so I can’t compare).

      • Willis
        I am bemused by Nicks claims of a 98F temperature at Reading. Its an interesting site and one I know well and a useful marker as its only 30 miles from Heathrow. It reached 90F or so on the 1st July.
        http://www.getreading.co.uk/news/reading-berkshire-news/reading-weather-record-high-temperatures-9564052
        The records on that site started in 1968 moving from an arguably warmer site nearer the town centre. However, in the intervening years Reading has expanded exponentially, ironically with many workers from Heathrow.
        Perhaps Nick can clarify just where in Reading the 98F was recorded?
        tonyb

    • Well, Willis, what is your point? Heathrow recorded 36.7°C. That’s 98.06°F. And all these other non-airport places around are recording 98°F. So why all the talk about jet engines etc?

      • Where in Reading? Heathrow. Accuweather figures for the two sites are identical throughout June and July.

    • Nick
      I have looked into this and what accuweather has done has taken Heathrow as the base temperature at a contentious 36.7 C rounded it up to 37C and applied it to all towns within 40 miles.
      You have then taken this at face value and converted it to 98F. See my comment to Willis. The Maximum in Reading was around 33.3 C or so or around 93F.It wasnt 98F
      tonyb

      • Tony,
        You may well be right – I was surprised by the uniformity. If so, I’m disappointed in their accuracy – the table is headed Reading, GB – local weather. And of course, I apologise if I was wrong – I’ll have to get better sources.

      • Actually, they do give an apparent location, which is opposite the Kemble Water centre in Vastern Road. But I think you are right that they are actually just echoing Heathrow temperatures.

      • Nick
        I have had this sort of problem with accuweather before in a number of countries .They seem to take one station round up the temperature and apply it to a number of other towns often with a quite different climate. As you know Britain is small and we have lots of microclimates so it is accentuated here.
        On July 1st it was by no means warm here in the South West close to the Met Office in Exeter.
        It was a short lived plume of hot air from Morocco that raised the temperatures and was by no means widespread over the entire UK.
        the temperatures before and after July 1st can be seen here
        http://www.accuweather.com/en/gb/reading/rg1-2/july-weather/330396?monyr=7/1/2015
        tonyb

      • I work in Reading, and my in car thermometer registered 32c. I can’t vouch for its accuracy, but it usually follows the local weather forecast.

      • Nick
        Further to Tony’s post above, St Albans is only about 5 miles south of the Rothamstead Research Centre, where one of the CET weather stations is located. The temperature graph for daily max temperatures (blue line) is interesting as it shows both that the peak was about 33.5 deg C (about 93 deg F) and it shows how short a duration these high temperatures were (high 20s the day before, mid 20s day after – subsequently we are having a fairly mixed July with some good warm and sunny days and some not so good..
        http://www.rothamsted.ac.uk/aen/ecn/MaxMin_MTH_T06_02.htm

  56. One thought about the effect of jets. There is actually data that might show how much of an effect there is (assuming it’s available). That’s data from 9/11 and the days surrounding it from ASOS and possibly nearby weather stations. Since everything was shut down on 9/12 I would assume you’d see a difference in temps between ASOS at a major airport and the nearby station that is far enough away (and not in the city) on 9/10 and a reduction in that difference on 9/12. This would be even more extreme at peak traffic times.

  57. Interesting to compare Wunderground stations around Heathrow. Here’s a few …
    1. IBUCKSIV1
    2. IWINDSOR2
    3. IMIDDLES2
    4. ISTAINES2
    Scroll down for July 1st history, run cursor over graphs for readings. No telling the quality of these sites but all seem to tell a similar story. Pretty much urban sprawl in all directions in these parts of course.

    • IENGLAND957 is interesting. This is Datchet Sailing Club which is only 4 klicks from the end of the north runway to the west (Kew Gardens is about 11 klicks east). It is by a lake, note current temp is about 2 degrees lower than the others. Probably a nice bit of kit, it records the full gambit including solar radiation. Times appear to be local (not GMT) on these WEB sites so ignore my comment below.
      The peak observed here at 6 minute intervals was 33.3 °C and there’s no five minute wonder spike to quicken warmist hearts. Regardless of calibration, clearly the Heathrow event was localised and short lived.

  58. Sorry to be slightly off topic, but where can I find how the monthly temperatures in Massachusetts for 2015 stack up with average monthly temperatures. We’ve been through a brutal winter, but I’m particularly interested in June 2015 which seemed unusually cool. Naturally the press is silent. Any ideas where to look?

    • Can’t help you with the state, but I went to Accuweather.com, pulled up Boston, clicked on “extended”, then on that page, clicked on “all 45 days”. That page will let you pull up the past months of the year. When you pull up June, it will show the actual. daily high and low for each day, along with the average high and low for that day.
      Yes, June was much cooler than average, with twice as many below average days as above. Moreover, several days were more than twenty degrees below average, whereas only one day got as much as thirteen degrees above average.
      Hope that helps.

      • Thanks. But I can assure you that the monthly averages are out there somewhere. I just can’t find them. They were in the news this past winter, and have been in the past whenever a summer month was particularly hot.
        The trope that increasing global temperature will bring more violent storms is never mentioned this summer when the Atlantic his produced 3 minimal tropical storms whose total duration was under 6 days.

  59. The interesting bit is that peak temperature at sites in several directions around the periphery of Heathrow arrived about an hour later. Very selective radiation in these parts.

  60. Just shows you how crazy the whole surface temperature record is. It’s not even measuring “the surface”, but the air molecules circulating near the surface which are constantly changing place with molecules from elsewhere. In the case of Heathrow, measuring air molecules that just passed through a jet engine.

    • You’ve got that right. The surface record is a mess. Whether this results from bad data as originally recorded or inept transcription of that data into digital form by underpaid employees of NOAA subcontractors has yet to be determined.

  61. From the MetO blog;
    “There were scattered clouds in the area that afternoon. Both Heathrow and Kew Gardens have instruments measuring solar radiation, shown in the graph below. Both sites recorded a general dip in solar radiation due to clouds from approximately 13:30 to 15:00 GMT which corresponds to a slight cooling at both sites. Heathrow saw a short gap in the clouds shortly after 14:00 GMT which resulted in a similarly short lived peak in temperature, while Kew Gardens remained cloudy. In turn Kew Gardens then saw a brief spell being sunnier than Heathrow just before 15:00 GMT and became warmer than Heathrow for about an hour.”
    http://blog.metoffice.gov.uk/2015/07/07/on-the-record-observing-a-heatwave/
    Kew does warm from around 14:24, but then warms even more from around 15:09 while local solar is falling until 15:36:
    https://metofficenews.files.wordpress.com/2015/07/1-july-2015-temperature-graph1.jpg

  62. As a bit of information I measured the peak temperature that day in Lincoln UK with my thermometer as 32.2c ,which compared well with the provisional 32.5c peek given by Waddington. My temperature readings are usually a bit higher then Waddington at peek temperature. The temperature was not so hot further north and perhaps outside of urban areas in the UK on that day.

  63. Regarding: “Well, it swings from a minimum of 130° (about southeast) to a maximum of 180° (south) during the hour. This is a not insignificant range of no less than fifty degrees.”:
    The most southerly wind in the wind direction graphic looks to me as the 14:13 one, and I determined from pixel positions that the direction was 167 degrees. The most easterly wind looks to me as the 14:38 one, and I similarly determined the direction as 129 degrees. This is a swing of 38 degrees.
    However, the most rapid 5-minute swing was from 167 at 14:13 to about 143 at 14:18, which is about 24 degrees. That swing looks like it separated four consecutive readings averaging (my eyeball estimate) ~160 degrees from seven consecutive readings averaging (my eyeball estimate) ~145 degrees. This may have caused the temperature to decrease after the first solar radiation spike.

    • Thanks, Donald, and I do appreciate a man who does what I do frequently, digitize graphics to extract the underlying information … but in this case, I fear you’ve wasted your appreciable talents. As I said in the head post:

      In any case, they kindly provided the data used in the graph, kudos to them for that, plus the wind direction and strength data so we could see that it’s the sun, stupid …

      My figures are taken directly from the wind direction data.
      w.

      • Exactly. I described that as going from about 130° to about 180° and the swing as about 50°. I prefer to round such numbers to more meaningful intervals (measuring wind direction to the tenth of a degree?).
        The problem is the cost of the numbers. I figure that each additional number I put in a document costs me one reader. Lots of folks out there don’t like numbers, so I use them like cayenne pepper—small doses for the best taste, and well-rounded …
        w.

  64. on a hot humid summer day the pressure altitude is almost 1000 feet higher than msl. Ground speeds on touch will be higher than normal due to that fact, thus lotsa reverse thrust will be mandatory to get the ground speed down before applying brakes. The last thing a captain wants is overheated brakes, an emergency slide evac, and a visit to the chief pilot’s office for bust to first officer or worse.
    Further, ground taxi and waiting in line on a hot day means keeping at least one engine a flightbidle (spoolled-up) to keep the A/C on a double deck jumbo operating for passenger comfort. The APU normally operates on ground so pilots can keep engined at ground idle (spoolled down), but that only provides electrical bus power and minimal fan flow to pass compartment with no or limited cooling.
    I would check the Heathrow records to see what the ground delays were that day compared to normal as well.

    • Interesting, Joel. I’d forgotten about the need to keep the A/C operating, particularly on a hot day. And in addition to the jet fuel burnt to power the A/C, you have the waste heat from the A/C condensers …
      I’ve mentioned before the amazing depth of experience among readers of WUWT. Almost everything that I can write about will cause the magical appearance of someone like yourself with insider expertise who is willing to share their knowledge of the situation.
      Much appreciated,
      w.

  65. All this is beside the point: When people are dropping dead like flies from a complete bitterly cold winter, “It’s weather, not climate” – but one hot day recorded (doubtfully, but even if genuine, just one day) becomes an end of the world doomsday panic. What int h… is the matter with these people?

  66. Interesting that lines drawn from the two rightmost turnoffs from that runway intersect just about exactlly on that weather station. And the turnoff to the left of those doesn’t miss that nexus by much.
    A conspiracy theorist might think that weather station location had been chosen deliberately, but don’t tell Lew…

  67. The UKMET Office might be quite good at predicting weather for the next few days.
    It has proven it is fairly bad at predicting the future climate.
    And I suspect it knows sweet FU about micro climate effects which was the most likely cause of the sharp peak in temperatures at Heathrow Airport.
    First up; I have been an Australian glider pilot since 1963 but have given the sport away since I have turned 77 years old.
    I have flown power aircraft since late 1959
    I am also a now retired grain farmer who farmed since I left school in 1954 and have lived and worked in the open and the weather all my life whilst closely watching and thinking about the incredible variety of weather phenomena I have seen, a lifetime study which was due to my interest and personal commitment to my sport of gliding or more accurately, Soaring
    The Met Offices supposed record temperatures DOES NOT need any jet exhaust or any other explanation
    to achieve that spurious high point in that recorded temperature high point.
    When you get past the mid 30C temperature range Glider pilots will often find a patch of trees or a complex of buildings or even the wind lee side of a small and steep hill to find where the still air wind shadow effect allows a very considerable warming of the localised ground level patch of air from the suns heat allied with the ground’s heat sink effect and the release of that heat to warm the air mass directly above it.
    In Heathrows situation, an even bigger, higher temperature heat sink in the seal and concrete in front of and in the wind shadow of the terminal buildings when a SE wind is blowing.
    This more often than not under the right circumstances such as the wind shadows I described above, the wind shadow effect results in a “thermal” being generated, [ a rising column of warmer, therefore expanded, therefore a lighter air mass than the surrounding air mass and therefore like a hot air balloon, same principle, the warmer lighter air mass rises and forms a thermal column entrapping and drawing air into it at the bottom and creating a “thermal” , a rapidly rising column of warmer lighter air used by glider pilots to cover hundreds of kilometres distance on a good day.] which then detaches itself as the parcel of warmer, lighter air begins to ascend and the newly created “thermal” then drifts downwind.
    Standing out on a sealed 30 metre wide Australian country runway which is one hell of a lot smaller than any sealed surface or concreted runways and hard surface standings at Heathrow, we often see thermals begin on that much higher than air temperature, heat sink sealed runway and then drift off down wind.
    When a thermal gust goes through it might take a half a minute or even a few minutes in open vistas , being slower to pass in heavily built up areas as the wind speed at ground levels is greatly reduced in velocity, for such a thermal gust depending on its size, intensity, the wind strength and etc for it to pass through and it is noticeable that the air within that thermal cell and the associated wind gust is degree or more warmer than before and after the thermal has passed through.
    The Heathrow five minute wind direction [above] also indicates that there was a minor shift in the wind direction consistent with the start of the rotation of a large warm air pool at ground level, the start of a thermal, towards a more southerly bearing [ banded at 14.13 in the above wind rose graph ] before the wind swung back past the average bearing further into the SE and then settled back over a few minutes to the before and after bearing.
    A very typical effect from the passing of a large “developing thermal” air mass.
    Further anybody riding in the back of a “ute” [ “utility” ; “pickup” to Americans ; riding in the back of a ute supposedly no longer allowed by our nanny state here in Australia,] at say 50 or more KPH on a warm to hot day, one will experience quite large patches of quite noticeably warmer air as in a couple or more degrees warmer for a some tens or even hundreds of metres followed by a sharp change in a few metres back to cooler air as the warmer patch of air is left behind and another patch of cooler air lasting some hundreds distance of metres is entered in turn.
    The Heathrow spike in temperature is entirely consistent with a normal and regularly experienced “thermal” created spikes of a degree or more passing slowly through the station after the “thermal” has come into existence in the SE wind shadow of the terminal buildings and then has broken away from the effects of the terminal buildings wind shadow and the very large heat sink effects of the sealed and concreted hard standings.
    It has consequently then drifted in this case, directly downwind from the terminal buildings wind shadow effect and across the station giving the station a sharp increase and then fall in temperature in line with the usual low level near ground level gliding described “thermal” temperature characteristics and in line with the temperature graph depicted in our headline post..

    • Excellent points, thanks!. Aviators, especially those who depend on rising columns of air for lift, are the real experts on the atmosphere and its behavior. You could teach our climate scientists a thing or two! The air isn’t that well mixed–inferring behavior from one location at one time (a peak temp) ignores essentially everything! Using a boiled-down average of daily highs and lows over a month of observations to describe our complex, chaotic atmosphere is next to useless.

      • Land subsets of global temperature datasets involve 3,652-3,623 daily highs and daily lows per decade, at each of thousands of stations. Places that get thermals tend to get several of them each day they occur. I don’t see any chance for any significant change in a recorded trend if one thermal hits a weather station instead of missing it, or vice versa. The main concern with surface stations is if during the period of record the surface around a station changes, the station changes, or the station is moved.

      • Sorry to be unclear. I’m confident that average highs and average lows can be collected and calculated and that influences such as jet wash or thermals are likely infrequent enough not to make a huge difference over many observations. I’m questioning the notion that averaging highs and lows relates well to an average daily temperature. Averaging the daily high with the daily low provides a number that does very little to describe the heat content of a day. The 15 minute spike at Heathrow that is under discussion here is a nice example–it skews the daily average high but with a very short interval of additional heat. I would prefer to see an integrated average of more frequent values taken over 24 hours since that would better reflect the heat content of the atmosphere for the day. Very rich data are being ignored in pursuit of a mostly meaningless average daily, monthly or yearly temperature.

    • Yes, I was thinking “thermals” too. Checked the British Gliding Associaton website (see “BGA ladder” -competative list of glider flights for each day) and it was a good soaring day, with 23 pages of results and seven flights over 600km. So it was quite thermic that day. And I think a thermal can easily suck warm jet exhaust a hundred meters of so as it pulls in air to feed the rising air thermal bubble.
      I do wonder whether these Met Office folks are concious of how they always seem to be defending a warmist world view (to paraphrase “no, no, no, couldn’t possibly be jet blast, must be global warming”) instead of actually doing science.
      PS: I haven’t checked them all, but I recognise a number of the stations listed in the records table as being airfields too.

    • Wouldn’t the turbulence from heavy aircraft taking off and landing at this particular site and time disrupt thermal formation ?

  68. I’ve seen no comment regarding aircraft direction and that could have a marginal effect. With the runways aligned 09 / 27 and the prevailing winds SW to SSW / WSW most take-offs / landings are towards the west. (My experience is that about 90% are westward.) With a southerly / south-easterly wind on July 1st, they would have been west to east.
    Another factor (from personal experience) is the time taken to get through the “traffic jam” before take-off. There is a secondary peak period around mid-day and having tried taking flights around then, to avoid peak times, I can say that it ain’t necessarily so.

  69. Aircraft using runway 09L during the time of the reported hottest temperature were as follows:
    1413 BA272 from San Diego Boeing 777-200
    1415 BA274 from Las Vegas Boeing 747-400
    1416 BA775 from Stockholm Airbus A320
    1417 BA842 from Dusseldorf Airbus A319
    1418 BA905 from Frankfurt Airbus A319
    1419 BA1445 from Edinburgh Airbus A320
    From a visual aspect I don’t see a strong correlation between the radiation (sunshine) and temperature plot.
    What I do see from the aircraft movements, were two large planes a 777 (two engine) and a 747 (four engine) landing with max reverse thrust close to the thermometers, ably assisted by a S/SE wind blowing the heat vortices in the thermometers direction.

    • Sorry for the nitpicking but I can’t stand it anymore: it’s just “Airbus 320”, not “Airbus A320”.

  70. It would help if I thought a bit more about the configuration of max thrust, of course landing on 09L it would have been further west on the runway. However on further analysis if the 747 had slowed on roll out and exited on taxiway A5 or A6 it would have needed a thrust boost to get rolling for exist. A5/A6 would have pointed its engines directly to the position of the thermometers, 120m away, still assisted by the S/SE wind blowing the heat vortices.

  71. It would be nice if all traffic at Heathrow could be stopped for a while in order to see what difference it would make to temperature. Maybe Greenpeace could arrange it 😉

  72. “We would have to compare the speed of a plane at 3000 feet during take-off and landing”
    Flightradar24.com will give you that information – just track an aircraft from departure, and you’ll get frequent updates of altitude and speed. Naturally, there will be quite a variation, depending on the size of aircraft, and its weight for a particular flight.
    “It would interesting to have a second weather station at Heathrow, well away from tarmac and well away from the one referred to in Willis’s article”
    Paul Homewood (who runs the “Not A Lot Of People Know That” blog) lists a number of nearby privately operated weather stations in some of the many posts that inspired Christopher Booker to pen the Telegraph piece:
    https://notalotofpeopleknowthat.wordpress.com/?s=Heathrow
    Look at the July the 3rd & 5th stories.

  73. Further to my last comment, here are some recent observations: British Airways B747 en-route to JFK passing 2925ft @ 180kts, a BA A320 to Helsinki passing 3075ft @ 230kts, Singapore Airlines A380 (en route to Singapore) passing 3025ft @ 230kts, a United B787 Dreamliner en route to Houston passing 3250ft @ 180kts, American Airlines A330 en route to Charlotte passing 3000ft @ 163kts
    Note that (virtually) all aircraft climb at a considerably greater rate than they descend during approach, when they are following a standard 3 degree glide-slope. Flightradar24 includes the rate of climb/descent information. This would mean the “3000ft Bubble” referred to earlier is much larger if both landing and departing aircraft are included.

  74. Reblogged this on the WeatherAction News Blog and commented:
    While some is from the acres of hot asphalt runways cooking in the sun, in part it’s from the actual burning of the fuel. Have you ever been caught by the blast from a jumbo jet, even from far away? I have, many times. It smells like kerosene, and it’s warmer than the surrounding air, sometimes much warmer. When one of these blasts hits you, you can easily feel the difference in temperature … and so can the airport thermometer.
    An excellent piece by Willis that really shows the Met Office must try harder. It was a record that day, but not a valid one. The Met Office contortions in defence of the narrative sadly undo every bit of their great historical works, showing instead their unswerving devotion to Climate Lysenkoism.

  75. Some figures about how far the jet plume extends beyond the tail of a 747 during takeoff (taken from official Boeing documentation at: http://www.boeing.com/assets/pdf/commercial/airports/acaps/747_8.pdf)
    200 mph (=Class 5 hurricane) 64 ft
    150 mph (=Class 4 hurricane) 241 ft
    100 mph (=Class 2 hurricane) 531 ft
    50 mph (=Strong Gale) 1748 ft
    35 mph (=Moderate Gale) 2588 ft
    According to the same source during taxying “Moderate Gale” will only extend about 130 feet on an absolutely flat taxiway, but even a 1% slope is enough to increase this to 320 feet with “Strong Gale” to about 100 feet.

  76. Anyone that thinks Heathrow isn’t one of the most pronounced heat-islands in the world and useless (or worse) as a climate indicator needs a lobotomy.

  77. I really love this web site…I have learned so much!
    While reading this article, I was guessing that the amount of air traffic during that period was at an unusual peak. I pictured a traffic jam of jets on the tarmac in front of the station, just idling and waiting for their gates to become available.

  78. Clive Best remarks:

    “A BA 747-400 originating from San Francisco, a BA 777 from Tokyo and an Etihan A380 superjumbo all landed within minutes of each other between ~ 14:00 and ~14:30 on July 1. Smaller aircraft normally exit well before they reach that exit, but large heavy aircraft need far more runway to stop. They must exit directly alongside the Met station, and as they turn SE towards the terminals their Jet engines accelerate thereby pumping hot exhausts directly towards the Stephensen screen.”

    • That’s strong evidence the temperature spike was jet-induced, but the A380 operator is Etihad Airways, not Etihan.

    • Clive Best has updated his analysis with better data, correct times:

      The heat spike occured more or less exactly at 14:15 GMT. Two BA 747-400s landed within 2 minues of each other at precisely the right time. The first BA 272 from San Diego landed at 14:13 GMT and the second BA 274 from Las Vegas landed at 14:15 GMT.

  79. I asked the UKMO whether the temperature record at Heathrow was reliable, in view of the increase in temperature relative to CET since 1948 and I received the following reply:
    Thank you for your email enquiry in connection with the temperatures recorded at Heathrow.
    As with all our sites, our weather station at Heathrow conforms to World Meteorological Organisation (WMO) guidelines in relation to site and specific sensor locations to ensure relativity across sites and for historical comparisons. Details of these guidelines may be of interest to you and can be found at http://www.wmo.int/pages/prog/www/IMOP/CIMO-Guide.html and ensure that a site is representative of the local area. While it isn’t possible to have an “ideal” or “normal” site this ensures that external factors are limited and to have continuity. All our sites are routinely visited by specialists and engineers to maintain high standards of recording and exposure of instrumentation along with accurate quality checks of observational data.
    The links below may be of interest to you and expand in further detail the points mentioned above.
    http://www.metoffice.gov.uk/climate/uk/interesting/july2015
    Discusses the heat wave and compares with other heat waves in the historical record
    http://blog.metoffice.gov.uk/2015/07/07/on-the-record-observing-a-heatwave/
    Discusses record at Heathrow and compares with other stations in the area
    http://www.climate.gov/news-features/event-tracker/summer-heat-wave-arrives-europe
    Heat wave more widely across Europe.
    http://www.carbonbrief.org/blog/2015/07/met-office-wind-data-dispels-doubt-about-cause-of-heathrow-high-temperatures/
    Therefore based upon the points covered, the increase in temperatures over the records at Heathrow can be considered an accurate and reliable representation of the local area, suitable for comparison against other sites and historical records.

  80. The thing that strikes me the most is that we are going to hourly readings vs twice a day. This guarantees meaningless high and low temperature records when compared to the old record. You only can compare readings at the 2 points in the day that were performed historically.

  81. Willis wrote: “… 6.13E+13 joules per day, of heat solely from the burning of the fuel …
    1227 hectares … 3,000 feet elevation. That’s about 1.12E+10 cubic metres of air, or about 1.43E+10 kg of air. So, imagine that we could put a transparent air-tight dome over Heathrow 3,000 feet (900 m) tall, and one day we burned 6.13E+13 joules worth of kerosene inside the dome, and 70% of that energy went into heat … how much would that raise the air temperature? Short answer? It would give about a 3°C temperature rise, which is 5.4°F.”
    Of course, planes can’t land with a transparent, air-tight dome over Heathrow. In the absence of such a doom, wind continuously sweeps the air warmed by burning jet fuel away from the airport and replaces it with fresh cooler air. With an area of 1227 hectares or 12 sq km, it should take a wind of only 3 kilometer per hour to sweep fresh air into the airport every hour and convert 3 degC (of warming each day) to a negligible 0.1 degC (of warming each hour). This problem could be fixed by assuming that the burning jet fuel warms only the lowest 300 feet of the air over the airport. Unfortunately, the principles fluid flow over surfaces predict a turbulent boundary layer that transfers heat vertically from the surface.
    Similar arguments suggest that the energy consumed in cities (which is probably much larger than a few dozen jet planes consume per hour in a 12 sq km airport) is not the main cause of UHI.
    Your arguments about sunshine and wind direction appear sensible, but what actually happened at Heathrow is irrelevant. Temperature records were set in numerous locations the same day elsewhere in England. And those records represent weather, not climate change.

    • Frank

      Temperature records were set in numerous locations the same day elsewhere in England. And those records represent weather, not climate change.

      Which other cities near London set climate records?

    • Thanks, Frank. I don’t recall ever making the claim that jet fuel burning was the cause of UHI. So you’re attacking a straw man. What I did instead was try to get a physical sense of just how much energy is in the jet fuel.
      My point was that if there is enough energy wandering around the airport that if it was released into a huge space above the airport it would jack the temperature by 3°C, there’s plenty to mess with temperature sensors. I note that you neglected to quote my disclaimer, viz:

      Now, of course as soon as the air is warmed by jet exhaust it starts rising, and the heat moves constantly upwards and outwards and cool air mixes in at the bottom, so there is no average 3°C temperature rise on the surface.

      So no, I don’t think that the jet fuel burning is the MAJOR cause of UHI … but a quick calculation shows that the fuel burned at Heathrow is about 1 W/m2, so it is too large to ignore entirely.
      Finally, you say:

      Your arguments about sunshine and wind direction appear sensible, but what actually happened at Heathrow is irrelevant. Temperature records were set in numerous locations the same day elsewhere in England. And those records represent weather, not climate change.

      I don’t understand why “what actually happened at Heathrow is irrelevant”. Yes, temperature records were set elsewhere … and most of them were at AIRPORTS. This is indeed relevant to the climate discussion.
      It is also not “irrelevant” because this “record high at Heathrow” meme has appeared all over the web. Hang on … OK, I find about 4,000 news articles discussing the record high, and lots more other analyses.
      Finally it is not “irrelevant” because according to the 72-point screaming headlines this was the “HOTTEST JULY DAY ON RECORD!!!”, so it is being hyped by the alarmists. As such, it is extremely relevant to find out whether this record is valid, or whether it’s just hot air (from jets).
      Because me, I’m not impressed by a temperature record high based on jet blast …
      w.
      PS—Your claim that “Similar arguments suggest that the energy consumed in cities (which is probably much larger than a few dozen jet planes consume per hour in a 12 sq km airport) is not the main cause of UHI” might be true … but it would have more force if you actually linked to one, just one, of your claimed “similar arguments” …

  82. No doubt that insolation LEADS the temperature in the rise to the day’s peak. What confuses many brainwashed into a “radiation-only” perspective is the subsequent cooling behavior, which is typically the result of moist convection–the principal mechanism of heat transfer from surface to atmosphere.

    • 1sky1 July 20, 2015 at 11:28 am

      No doubt that insolation LEADS the temperature in the rise to the day’s peak. What confuses many brainwashed into a “radiation-only” perspective is the subsequent cooling behavior, which is typically the result of moist convection–the principal mechanism of heat transfer from surface to atmosphere.

      Thanks, 1sky1. While you are correct that the “principal mechanism of heat transfer from surface to atmosphere” is what you call “moist convection” (by which I suspect you mean evapotranspiration), it is not the principal way that the surface loses energy. That indeed would be radiation.
      w.

    • Willis:
      Moist convection is the inanimate transport of humid air from the near-surface boundary layer into the atmosphere. It has little to do with the transpiration produced by plant life. And if you examine the results of careful energy-transfer experiments world-wide in terms of the Bowen ratio, instead of the cartoon physics of Trenberth et al., you’ll discover the real-world dominance of moist convection.

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