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The automated weather broadcast at Yuma airport in Arizona reports the runway temperature. Yuma is a joint civilian/military use airport and some fast jets hav

The automated weather broadcast at Yuma airport in Arizona reports the runway temperature. Yuma is a joint civilian/military use airport and some fast jets have a surface temperature limit for their tires. I was there doing some flight test work once and it was reporting 160F, it wasn't even a super hot day.

collegeburner 4y ago
yeah lol not surprised. im in texas, not even as hot as arizona, and friends motorcycle kickstands have lowkey melted into ashpalt a few times.
konschubert 4y ago
They probably use a different ~~tarmac~~ material composition for the runway.
- kube-system 4y ago
  Luton is all asphalt. The long runway at Yuma is concrete and the shorter ones are part asphalt part concrete. And they likely chose the asphalt formulation appropriately given that they’re in the middle of a desert.
  - squarefoot 4y ago
    I would expect their asphalt being a lot harder and more heat resistant than the one that let my motorcycle fall multiple times in the past years because it melt during summer heat. I clearly wouldn't expect airplanes wheels to "sink" into asphalt like my bike stand, but they need a strong grip when braking during landings which I doubt a much softer surface would offer. Not an expert though, just speculating.
    - jacquesm 4y ago
      A softer surface would give more grip, not less. In fact it would give so much grip that it starts to adhere to the tires.
      - squarefoot 4y ago
        You're right of course, what I wondered was if the asphalt could become so soft that it loses consistency; some of it surely adheres to the tires, but what if it would do that by detaching from the runway? However, I'm certainly biased for having seen asphalt so softened by summer heat that I could leave my tracks just by walking on it.
      - Scoundreller 4y ago
        I’d assume rainy UK would have softer runway surfaces for wet-weather performance. Unlike car tires where people may switch them between climates/seasons, aircraft tires need to be fairly universal.
onlyrealcuzzo 4y ago
In case anyone is curious why tarmac gets so hot: > The rate at which an object can reflect solar radiation is called its albedo [source: Budikova]. The bigger the albedo something has, the better it reflects radiation. Traditional asphalt has a low albedo, which means it reflects radiation poorly and instead absorbs it. Asphalt has an albedo of ~0.05 - which means it absorbs ~95% of solar radiation. Tarmac is ~0.1 - which means ~90%.
- drhodes 4y ago
  I didn't know there was a difference between the two! > Asphalt is a mixture of aggregates and bitumen that needs up to two days before it completely cures. Whereas, Tarmac is a combination of crushed stone and tar that cures quickly. https://tarmacdriveways.ie/key-differences-tarmac-vs-asphalt-driveways https://tarmacdriveways.ie/key-differences-tarmac-vs-asphalt...
  - senkora 4y ago
    From your link I learned that tarmac is short for tarmacadam, named after John Macadam, who is also the name-origin for macadamia nuts. https://en.m.wikipedia.org/wiki/John_Macadam https://en.m.wikipedia.org/wiki/John_Macadam
    - the_jeremy 4y ago
      That is incorrect. John McAdam[0] has the name for tarmac, while John Macadam[1] has the name for macadamia nuts. 0: https://en.wikipedia.org/wiki/John_Loudon_McAdam https://en.wikipedia.org/wiki/John_Loudon_McAdam 1: https://en.m.wikipedia.org/wiki/John_Macadam https://en.m.wikipedia.org/wiki/John_Macadam
      - senkora 4y ago
        Thanks for the correction! I can no longer edit my comment but you are right.
    - touisteur 4y ago
zerkten 4y ago
Have Yuma temperatures actually changed that much? A quick check suggests that the level of change is much smaller than that in the UK. Climate change has increased the extremes in the UK quite significantly in the last 40 years. It's a case that the changes in extremes are not accounted for in UK planning whereas Yuma is known to be consistently very hot.
- psi75 4y ago
  I buy the 71 C ground temperature; ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded. This is also why rails buckle more than you'd expect: on a 40 C day, you're likely to see the rails heating up to 60-65 (as in, if you touch them, your finger will burn).
  - nomel 4y ago
    > ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded Ground temperatures are almost entirely responsible for the majority of the thermal energy/temperature put into the air, down at the surface.
- yetanotherloser 4y ago
  Also I'm sorry but the UK bloody loves a bit of weather melodrama. Climate change is a big problem but the specific effect of it on the UK in particular has honestly not been very bad at all yet. Tarmac has been melting in the heat here longer than I've been alive, which makes me suspect we use weak, crappy British tarmac. This was a little bit hotter than previous heatwaves, which is bad, but felt about the same and has also been really short - not sure what to make of that. However we scarcely get a weekend here without some "most (x) ever in (y)" fuss and haven't in 40 years which is really getting quite tiresome and making it harder to respect the real problems. I'll worry about it when I'm done drinking gin in the rain.
  - throwaway821909 4y ago
    >most (x) ever in (y) The hottest temperature ever recorded here isn't some niche thing like most rainy April for 5 years. Also maybe the fact that there's constantly new unusual weather should tell us something.
HarHarVeryFunny 4y ago
I've been at Phoenix airport on a hot, but not crazy hot, day where the parking lot asphalt was tacky and stuck to your shoes.
badcppdev 4y ago
Latitude of Yuma, US: 32.6° N Latitude of London, UK: 51.5° N To be clear they are talking about the air temperature rather than runway temperature and I've added the latitude so you can understand why it's a big deal that London has hit 40 degrees.
- fdsafdsfdsa 4y ago
  While we're picking random data points - Malillia (Sweden), at 57° N, set a record temperature of 38°C in 1947.
  - secretsatan 4y ago
    Oh wow, that’s really interesting, was it just a freak event or part of a trend?
    - secretsatan 4y ago
      -> Hard to Say That’s weird, some cursory searches show a definite upward trend for quite some time, i do find these weird sites where they consistently pick outliers in a dishonest manner. It really wouldn’t be worth engaging with them though
      - fdsafdsfdsa 4y ago
    - fdsafdsfdsa 4y ago
    - formerkrogemp 4y ago
      Trend. Check out the latest IPCC report for more info.
  - MobiusHorizons 4y ago
    They are not random. Those are the two locations being discussed in the thread you replied to :)
derefr 4y ago
Any reason that airports in super-hot places like that, don't run heat-transfer coils under their runways, to cool them down with a heat pump like a skating rink does? Runways aren't an order-of-magnitude larger in surface area than skating rinks, so it's not cost. And they wouldn't even need to turn on the heat pump for 3/4ths of the year. Do we just not know how to create heat-transfer coils that wouldn't break from the stress of planes landing "on" them?
- kevin_thibedeau 4y ago
  They either use concrete or have different asphalt blends that handle higher temperatures.
- morsch 4y ago
  I imagine skating rinks in temperate/hot places are indoors and well insulated. Your solution would work well for an indoor runway.
- bigbillheck 4y ago
  > Runways aren't an order-of-magnitude larger in surface area than skating rinks, International hockey rinks are 30m by 60m. My local airport, which isn't that big as far as these things go, has two runways each of size 45m by 2200m. That's 55x larger per runway.
- mcguire 4y ago
  Hm. An Olympic ice rink is 30mx60m, or 1800m^2. The "largest ice arena complex in the world" (https://en.wikipedia.org/wiki/Schwan_Super_Rink https://en.wikipedia.org/wiki/Schwan_Super_Rink) is 28,000m^2 but has 8 Olympic ice rink, sort of. Yuma International/MCAS has roughly 540,000m^2 of runway (plus taxiways).
- badcppdev 4y ago
  Your comment fascinates me. A normal ice hockey rink is 1,800 square meters. The biggest indoor ice rink in the US is the Schwan Super Rink = 28,000 sqm which consists of 8 separate rinks. Yuma's 4 runways total 543,000 sqm. At midday those runways are absorbing 543MW of energy from the Sun. So that might require 100-200KW of electricity to run the heat pumps. And then you still need somewhere to dump the heat. In short, I think the reason they don't cool runways is due to the cost.
Consultant32452 4y ago
The Phoenix airport has to close down during peak temperatures on summer days because it exceeds the maximum operating temperature of the airplanes. Pretty cool.

collegeburner 4y ago

yeah lol not surprised. im in texas, not even as hot as arizona, and friends motorcycle kickstands have lowkey melted into ashpalt a few times.

konschubert 4y ago

They probably use a different ~~tarmac~~ material composition for the runway.

kube-system 4y ago
Luton is all asphalt. The long runway at Yuma is concrete and the shorter ones are part asphalt part concrete. And they likely chose the asphalt formulation appropriately given that they’re in the middle of a desert.
- squarefoot 4y ago
  I would expect their asphalt being a lot harder and more heat resistant than the one that let my motorcycle fall multiple times in the past years because it melt during summer heat. I clearly wouldn't expect airplanes wheels to "sink" into asphalt like my bike stand, but they need a strong grip when braking during landings which I doubt a much softer surface would offer. Not an expert though, just speculating.
  - jacquesm 4y ago
    A softer surface would give more grip, not less. In fact it would give so much grip that it starts to adhere to the tires.
    - squarefoot 4y ago
      You're right of course, what I wondered was if the asphalt could become so soft that it loses consistency; some of it surely adheres to the tires, but what if it would do that by detaching from the runway? However, I'm certainly biased for having seen asphalt so softened by summer heat that I could leave my tracks just by walking on it.
    - Scoundreller 4y ago
      I’d assume rainy UK would have softer runway surfaces for wet-weather performance. Unlike car tires where people may switch them between climates/seasons, aircraft tires need to be fairly universal.

onlyrealcuzzo 4y ago

In case anyone is curious why tarmac gets so hot: > The rate at which an object can reflect solar radiation is called its albedo [source: Budikova]. The bigger the albedo something has, the better it reflects radiation. Traditional asphalt has a low albedo, which means it reflects radiation poorly and instead absorbs it. Asphalt has an albedo of ~0.05 - which means it absorbs ~95% of solar radiation. Tarmac is ~0.1 - which means ~90%.

drhodes 4y ago
I didn't know there was a difference between the two! > Asphalt is a mixture of aggregates and bitumen that needs up to two days before it completely cures. Whereas, Tarmac is a combination of crushed stone and tar that cures quickly. https://tarmacdriveways.ie/key-differences-tarmac-vs-asphalt-driveways https://tarmacdriveways.ie/key-differences-tarmac-vs-asphalt...
- senkora 4y ago
  From your link I learned that tarmac is short for tarmacadam, named after John Macadam, who is also the name-origin for macadamia nuts. https://en.m.wikipedia.org/wiki/John_Macadam https://en.m.wikipedia.org/wiki/John_Macadam
  - the_jeremy 4y ago
    That is incorrect. John McAdam[0] has the name for tarmac, while John Macadam[1] has the name for macadamia nuts. 0: https://en.wikipedia.org/wiki/John_Loudon_McAdam https://en.wikipedia.org/wiki/John_Loudon_McAdam 1: https://en.m.wikipedia.org/wiki/John_Macadam https://en.m.wikipedia.org/wiki/John_Macadam
    - senkora 4y ago
      Thanks for the correction! I can no longer edit my comment but you are right.
  - touisteur 4y ago

zerkten 4y ago

Have Yuma temperatures actually changed that much? A quick check suggests that the level of change is much smaller than that in the UK. Climate change has increased the extremes in the UK quite significantly in the last 40 years. It's a case that the changes in extremes are not accounted for in UK planning whereas Yuma is known to be consistently very hot.

psi75 4y ago
I buy the 71 C ground temperature; ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded. This is also why rails buckle more than you'd expect: on a 40 C day, you're likely to see the rails heating up to 60-65 (as in, if you touch them, your finger will burn).
- nomel 4y ago
  > ground temperatures can be 25-35 C hotter than the ambient air temperature, which is what gets recorded Ground temperatures are almost entirely responsible for the majority of the thermal energy/temperature put into the air, down at the surface.
yetanotherloser 4y ago
Also I'm sorry but the UK bloody loves a bit of weather melodrama. Climate change is a big problem but the specific effect of it on the UK in particular has honestly not been very bad at all yet. Tarmac has been melting in the heat here longer than I've been alive, which makes me suspect we use weak, crappy British tarmac. This was a little bit hotter than previous heatwaves, which is bad, but felt about the same and has also been really short - not sure what to make of that. However we scarcely get a weekend here without some "most (x) ever in (y)" fuss and haven't in 40 years which is really getting quite tiresome and making it harder to respect the real problems. I'll worry about it when I'm done drinking gin in the rain.
- throwaway821909 4y ago
  >most (x) ever in (y) The hottest temperature ever recorded here isn't some niche thing like most rainy April for 5 years. Also maybe the fact that there's constantly new unusual weather should tell us something.

HarHarVeryFunny 4y ago

I've been at Phoenix airport on a hot, but not crazy hot, day where the parking lot asphalt was tacky and stuck to your shoes.

badcppdev 4y ago

Latitude of Yuma, US: 32.6° N Latitude of London, UK: 51.5° N To be clear they are talking about the air temperature rather than runway temperature and I've added the latitude so you can understand why it's a big deal that London has hit 40 degrees.

fdsafdsfdsa 4y ago
While we're picking random data points - Malillia (Sweden), at 57° N, set a record temperature of 38°C in 1947.
- secretsatan 4y ago
  Oh wow, that’s really interesting, was it just a freak event or part of a trend?
  - secretsatan 4y ago
    -> Hard to Say That’s weird, some cursory searches show a definite upward trend for quite some time, i do find these weird sites where they consistently pick outliers in a dishonest manner. It really wouldn’t be worth engaging with them though
    - fdsafdsfdsa 4y ago
  - fdsafdsfdsa 4y ago
  - formerkrogemp 4y ago
    Trend. Check out the latest IPCC report for more info.
- MobiusHorizons 4y ago
  They are not random. Those are the two locations being discussed in the thread you replied to :)

derefr 4y ago

Any reason that airports in super-hot places like that, don't run heat-transfer coils under their runways, to cool them down with a heat pump like a skating rink does? Runways aren't an order-of-magnitude larger in surface area than skating rinks, so it's not cost. And they wouldn't even need to turn on the heat pump for 3/4ths of the year. Do we just not know how to create heat-transfer coils that wouldn't break from the stress of planes landing "on" them?

kevin_thibedeau 4y ago
They either use concrete or have different asphalt blends that handle higher temperatures.
morsch 4y ago
I imagine skating rinks in temperate/hot places are indoors and well insulated. Your solution would work well for an indoor runway.
bigbillheck 4y ago
> Runways aren't an order-of-magnitude larger in surface area than skating rinks, International hockey rinks are 30m by 60m. My local airport, which isn't that big as far as these things go, has two runways each of size 45m by 2200m. That's 55x larger per runway.
mcguire 4y ago
Hm. An Olympic ice rink is 30mx60m, or 1800m^2. The "largest ice arena complex in the world" (https://en.wikipedia.org/wiki/Schwan_Super_Rink https://en.wikipedia.org/wiki/Schwan_Super_Rink) is 28,000m^2 but has 8 Olympic ice rink, sort of. Yuma International/MCAS has roughly 540,000m^2 of runway (plus taxiways).
badcppdev 4y ago
Your comment fascinates me. A normal ice hockey rink is 1,800 square meters. The biggest indoor ice rink in the US is the Schwan Super Rink = 28,000 sqm which consists of 8 separate rinks. Yuma's 4 runways total 543,000 sqm. At midday those runways are absorbing 543MW of energy from the Sun. So that might require 100-200KW of electricity to run the heat pumps. And then you still need somewhere to dump the heat. In short, I think the reason they don't cool runways is due to the cost.

Consultant32452 4y ago

The Phoenix airport has to close down during peak temperatures on summer days because it exceeds the maximum operating temperature of the airplanes. Pretty cool.