Is it colder at the approach end of the runway?

[Chris W]

My dad drives along the south side of OKC to work every day and his OAT
in his car always goes a few degrees colder around the where the
extended centerline for the runways would intersect the road. Then it
goes right back up after he is through that area. He thinks this is
because the airplanes are descending from very cold air and bringing
down some of it with them. He has noted that this isn't always the case
but it often is. You would think most of the traffic would be landing
from the north since our winds are mostly from the south, but it seems
like I see a lot of traffic coming in from the south, maybe because it
is easier for the traffic from DFW to just come strait in.

Anyway, any one here think it is really the case that the planes are
causing the temperature to be lower on the approach end of the runway?
I guess if he monitored the ATIS frequency to find out which runway was
active when he drives by every day, he would have a better idea.


--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
One stop wish list for any gift,
from anywhere, for any occasion!
http://thewishzone.com

[Chris W]

Chris W wrote:
maybe because it
> is easier for the traffic from DFW to just come strait in.
>
Make that "straight"
--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
One stop wish list for any gift,
from anywhere, for any occasion!
http://thewishzone.com

[Mxsmanic]

Chris W writes:

> My dad drives along the south side of OKC to work every day and his OAT
> in his car always goes a few degrees colder around the where the
> extended centerline for the runways would intersect the road. Then it
> goes right back up after he is through that area. He thinks this is
> because the airplanes are descending from very cold air and bringing
> down some of it with them.

I would not have thought of that, but it's certainly plausible. Aircraft
produce a massive downwash of air behind them that (at least in theory) drifts
downward until it encounters the ground. In the case of aircraft very near
the surface (as during landing and take-off), it's entirely possible that they
might produce gentle downdrafts of colder air that reach the ground. I think
it would take fairly constant traffic using the runway to make a clear
difference, though.

It's a bit like the constant wind that one often feels by the side of a
highway or major city street, always in the direction of traffic. Moving
vehicles do displace a lot of air.

> He has noted that this isn't always the case
> but it often is. You would think most of the traffic would be landing
> from the north since our winds are mostly from the south, but it seems
> like I see a lot of traffic coming in from the south, maybe because it
> is easier for the traffic from DFW to just come strait in.

Things like noise abatement and other concerns might obligate the airport to
work against the wind, at least if the wind speed is low enough (less than 10
knots or so).

> Anyway, any one here think it is really the case that the planes are
> causing the temperature to be lower on the approach end of the runway?

I think it's plausible.

Also, if the extended centerline is mostly open area (not buildings or roads),
that could make a difference as well. An open field is often colder than a
large building, because it absorbs solar energy less rapidly and retains it
less efficiently, and because it doesn't generate any heat of its own.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Bertie the Bunyip[_2_]]

Mxsmanic > wrote in
:

> Chris W writes:
>
>> My dad drives along the south side of OKC to work every day and his
>> OAT in his car always goes a few degrees colder around the where the
>> extended centerline for the runways would intersect the road. Then
>> it goes right back up after he is through that area. He thinks this
>> is because the airplanes are descending from very cold air and
>> bringing down some of it with them.
>
> I would not have thought of that, but it's certainly plausible.
> Aircraft produce a massive downwash of air behind them that (at least
> in theory) drifts downward until it encounters the ground. In the
> case of aircraft very near the surface (as during landing and
> take-off), it's entirely possible that they might produce gentle
> downdrafts of colder air that reach the ground. I think it would take
> fairly constant traffic using the runway to make a clear difference,
> though.
>
> It's a bit like the constant wind that one often feels by the side of
> a highway or major city street, always in the direction of traffic.
> Moving vehicles do displace a lot of air.
>
>> He has noted that this isn't always the case
>> but it often is. You would think most of the traffic would be
>> landing from the north since our winds are mostly from the south, but
>> it seems like I see a lot of traffic coming in from the south, maybe
>> because it is easier for the traffic from DFW to just come strait in.
>
> Things like noise abatement and other concerns might obligate the
> airport to work against the wind, at least if the wind speed is low
> enough (less than 10 knots or so).
>
>> Anyway, any one here think it is really the case that the planes are
>> causing the temperature to be lower on the approach end of the
>> runway?
>
> I think it's plausible.

You would, fjukktard.


Bertie

[Jim Macklin]

It is farther away from the built-up areas of the town, so
it is cooler. Houses make heat and so do factories.



|
| > Chris W writes:
| >
| >> My dad drives along the south side of OKC to work every
day and his
| >> OAT in his car always goes a few degrees colder around
the where the
| >> extended centerline for the runways would intersect the
road. Then
| >> it goes right back up after he is through that area.
He thinks this
| >> is because the airplanes are descending from very cold
air and
| >> bringing down some of it with them.
| >
| > I would not have thought of that, but it's certainly
plausible.
| > Aircraft produce a massive downwash of air behind them
that (at least
| > in theory) drifts downward until it encounters the
ground. In the
| > case of aircraft very near the surface (as during
landing and
| > take-off), it's entirely possible that they might
produce gentle
| > downdrafts of colder air that reach the ground. I think
it would take
| > fairly constant traffic using the runway to make a clear
difference,
| > though.
| >
| > It's a bit like the constant wind that one often feels
by the side of
| > a highway or major city street, always in the direction
of traffic.
| > Moving vehicles do displace a lot of air.
| >
| >> He has noted that this isn't always the case
| >> but it often is. You would think most of the traffic
would be
| >> landing from the north since our winds are mostly from
the south, but
| >> it seems like I see a lot of traffic coming in from the
south, maybe
| >> because it is easier for the traffic from DFW to just
come strait in.
| >
| > Things like noise abatement and other concerns might
obligate the
| > airport to work against the wind, at least if the wind
speed is low
| > enough (less than 10 knots or so).
| >
| >> Anyway, any one here think it is really the case that
the planes are
| >> causing the temperature to be lower on the approach end
of the
| >> runway?
| >
| > I think it's plausible.

[Maxwell]

"Chris W" > wrote in message
...
> My dad drives along the south side of OKC to work every day and his OAT in
> his car always goes a few degrees colder around the where the extended
> centerline for the runways would intersect the road. Then it goes right
> back up after he is through that area. He thinks this is because the
> airplanes are descending from very cold air and bringing down some of it
> with them. He has noted that this isn't always the case but it often is.
> You would think most of the traffic would be landing from the north since
> our winds are mostly from the south, but it seems like I see a lot of
> traffic coming in from the south, maybe because it is easier for the
> traffic from DFW to just come strait in.
>
> Anyway, any one here think it is really the case that the planes are
> causing the temperature to be lower on the approach end of the runway? I
> guess if he monitored the ATIS frequency to find out which runway was
> active when he drives by every day, he would have a better idea.
>
>
Which airport in OKC???

[Marco Leon]

Maybe an active localizer/glideslope signal is affecting the thermometer
components. Air does not "stick" to an airframe enough to change the ambient
temperature of a given area no matter how small.

Marco

"Chris W" > wrote in message
...
> My dad drives along the south side of OKC to work every day and his OAT in
> his car always goes a few degrees colder around the where the extended
> centerline for the runways would intersect the road. Then it goes right
> back up after he is through that area. He thinks this is because the
> airplanes are descending from very cold air and bringing down some of it
> with them. He has noted that this isn't always the case but it often is.
> You would think most of the traffic would be landing from the north since
> our winds are mostly from the south, but it seems like I see a lot of
> traffic coming in from the south, maybe because it is easier for the
> traffic from DFW to just come strait in.
>
> Anyway, any one here think it is really the case that the planes are
> causing the temperature to be lower on the approach end of the runway? I
> guess if he monitored the ATIS frequency to find out which runway was
> active when he drives by every day, he would have a better idea.

[[email protected]]

Chris W > wrote:
> My dad drives along the south side of OKC to work every day and his OAT
> in his car always goes a few degrees colder around the where the
> extended centerline for the runways would intersect the road. Then it
> goes right back up after he is through that area. He thinks this is
> because the airplanes are descending from very cold air and bringing
> down some of it with them. He has noted that this isn't always the case
> but it often is. You would think most of the traffic would be landing
> from the north since our winds are mostly from the south, but it seems
> like I see a lot of traffic coming in from the south, maybe because it
> is easier for the traffic from DFW to just come strait in.

> Anyway, any one here think it is really the case that the planes are
> causing the temperature to be lower on the approach end of the runway?
> I guess if he monitored the ATIS frequency to find out which runway was
> active when he drives by every day, he would have a better idea.

I doubt it.

If airplanes were having an effect on air temperature, I would expect
it would be warmer from all the engine heat, just as freeways are
warmer then the adjacent area.

Most likely it is due to the local arrangement of "stuff" such as
asphalt, concrete, trees, grass, buildings, etc.

--
Jim Pennino

Remove .spam.sux to reply.

[Robert M. Gary]

On Apr 2, 8:25 am, wrote:
> Chris W > wrote:
> > My dad drives along the south side of OKC to work every day and his OAT
> > in his car always goes a few degrees colder around the where the
> > extended centerline for the runways would intersect the road. Then it
> > goes right back up after he is through that area. He thinks this is
> > because the airplanes are descending from very cold air and bringing
> > down some of it with them. He has noted that this isn't always the case
> > but it often is. You would think most of the traffic would be landing
> > from the north since our winds are mostly from the south, but it seems
> > like I see a lot of traffic coming in from the south, maybe because it
> > is easier for the traffic from DFW to just come strait in.
> > Anyway, any one here think it is really the case that the planes are
> > causing the temperature to be lower on the approach end of the runway?
> > I guess if he monitored the ATIS frequency to find out which runway was
> > active when he drives by every day, he would have a better idea.
>
> I doubt it.
>
> If airplanes were having an effect on air temperature, I would expect
> it would be warmer from all the engine heat, just as freeways are
> warmer then the adjacent area.
>
> Most likely it is due to the local arrangement of "stuff" such as
> asphalt, concrete, trees, grass, buildings, etc.

I live near Sacramento where we have long periods of 100+ degree
temps. The gov't has been doing research here on the affect of asphalt
and roofs (not sure why) on temps. They fly a plane overhead in the
afternoon with sensitive heat detecting equipment. They seem to
believe the city is much hotter simply because of the pavement and the
roofs.

-Robert

[Kev]

On Apr 2, 12:09 pm, "Robert M. Gary" > wrote:
> I live near Sacramento where we have long periods of 100+ degree
> temps. The gov't has been doing research here on the affect of asphalt
> and roofs (not sure why) on temps. They fly a plane overhead in the
> afternoon with sensitive heat detecting equipment. They seem to
> believe the city is much hotter simply because of the pavement and the
> roofs.

It seems logical.

In New York City, it's always 6-8 degrees warmer at night than the
suburbs, supposedly because of the heat held by the buildings.

Cheers,
Kev

[Maxwell]

"Kev" > wrote in message
oups.com...
> On Apr 2, 12:09 pm, "Robert M. Gary" > wrote:
>> I live near Sacramento where we have long periods of 100+ degree
>> temps. The gov't has been doing research here on the affect of asphalt
>> and roofs (not sure why) on temps. They fly a plane overhead in the
>> afternoon with sensitive heat detecting equipment. They seem to
>> believe the city is much hotter simply because of the pavement and the
>> roofs.
>
> It seems logical.
>
> In New York City, it's always 6-8 degrees warmer at night than the
> suburbs, supposedly because of the heat held by the buildings.
>

Yeah, that almost sounds like a pork barrel project to me. I would think
there was tons of information on that subject already stuffing their file
cabnets.

[[email protected]]

Robert M. Gary > wrote:
> On Apr 2, 8:25 am, wrote:
> > Chris W > wrote:
> > > My dad drives along the south side of OKC to work every day and his OAT
> > > in his car always goes a few degrees colder around the where the
> > > extended centerline for the runways would intersect the road. Then it
> > > goes right back up after he is through that area. He thinks this is
> > > because the airplanes are descending from very cold air and bringing
> > > down some of it with them. He has noted that this isn't always the case
> > > but it often is. You would think most of the traffic would be landing
> > > from the north since our winds are mostly from the south, but it seems
> > > like I see a lot of traffic coming in from the south, maybe because it
> > > is easier for the traffic from DFW to just come strait in.
> > > Anyway, any one here think it is really the case that the planes are
> > > causing the temperature to be lower on the approach end of the runway?
> > > I guess if he monitored the ATIS frequency to find out which runway was
> > > active when he drives by every day, he would have a better idea.
> >
> > I doubt it.
> >
> > If airplanes were having an effect on air temperature, I would expect
> > it would be warmer from all the engine heat, just as freeways are
> > warmer then the adjacent area.
> >
> > Most likely it is due to the local arrangement of "stuff" such as
> > asphalt, concrete, trees, grass, buildings, etc.

> I live near Sacramento where we have long periods of 100+ degree
> temps. The gov't has been doing research here on the affect of asphalt
> and roofs (not sure why) on temps. They fly a plane overhead in the
> afternoon with sensitive heat detecting equipment. They seem to
> believe the city is much hotter simply because of the pavement and the
> roofs.

They are doing research on "global warming".

One of the objections to global warming data is that much of it is
from cities and the contention by many is that cities are hotter mostly
because they are asphalt and concrete, not because the Earth is warming.

The same objection applies to temperature data from airports.

--
Jim Pennino

Remove .spam.sux to reply.

[Gig 601XL Builder]

Robert M. Gary wrote:

>
> I live near Sacramento where we have long periods of 100+ degree
> temps. The gov't has been doing research here on the affect of asphalt
> and roofs (not sure why) on temps. They fly a plane overhead in the
> afternoon with sensitive heat detecting equipment. They seem to
> believe the city is much hotter simply because of the pavement and the
> roofs.
>
> -Robert

They
re spending money to figure that out. I thought that was common knowledge.

[Jose]

> re spending money to figure that out. I thought that was common knowledge.

Well, sometimes things that are common knowledge are incorrect.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Gig 601XL Builder]

Jose wrote:
>> re spending money to figure that out. I thought that was common
>> knowledge.
>
> Well, sometimes things that are common knowledge are incorrect.
>
> Jose

Jose, you sound like your buddy MX. When I returned from luch today I walked
from a concrete parking lot over about 10 feet of grass to enter the
building. I did not need airborne equipment to tell me it was warmer over
the concrete than it was over the grass.

[Robert M. Gary]

On Apr 2, 11:13 am, "Gig 601XL Builder" <wrDOTgiaconaATsuddenlink.net>
wrote:
> Jose wrote:
> >> re spending money to figure that out. I thought that was common
> >> knowledge.
>
> > Well, sometimes things that are common knowledge are incorrect.
>
> > Jose
>
> Jose, you sound like your buddy MX. When I returned from luch today I walked
> from a concrete parking lot over about 10 feet of grass to enter the
> building. I did not need airborne equipment to tell me it was warmer over
> the concrete than it was over the grass.

hehehe, I'm sure that's true. My guess is that they are trying to
quantify the effect, maybe even come up with a formula to predict the
effect on temps by cities. They also mentioned that some roofing
material appears to bring more heat than others and that it may affect
the cities temps.

-Robert

[Robert M. Gary]

On Apr 2, 11:13 am, "Gig 601XL Builder" <wrDOTgiaconaATsuddenlink.net>
wrote:
> Jose wrote:
> >> re spending money to figure that out. I thought that was common
> >> knowledge.
>
> > Well, sometimes things that are common knowledge are incorrect.
>
> > Jose
>
> Jose, you sound like your buddy MX. When I returned from luch today I walked
> from a concrete parking lot over about 10 feet of grass to enter the
> building. I did not need airborne equipment to tell me it was warmer over
> the concrete than it was over the grass.

BTW: My original interest in the story was thinking about the lucky
pilot who got the job to fly a Citation (as I recall) around in
circles for 4 hours/day. Where do I sign up? ;)

-robert

[[email protected]]

Gig 601XL Builder <wrDOTgiaconaATsuddenlink.net> wrote:
> Jose wrote:
> >> re spending money to figure that out. I thought that was common
> >> knowledge.
> >
> > Well, sometimes things that are common knowledge are incorrect.
> >
> > Jose

> Jose, you sound like your buddy MX. When I returned from luch today I walked
> from a concrete parking lot over about 10 feet of grass to enter the
> building. I did not need airborne equipment to tell me it was warmer over
> the concrete than it was over the grass.

Well, yeah, but I wouldn't use that to make the decision as to whether
or not huge piles of money should be spent to combat global warming.

I think we need something from traceable, calibrated instruments with
error bars on the numbers, which is what hopefully the airplane is
getting.

--
Jim Pennino

Remove .spam.sux to reply.

[Vaughn Simon]

"Marco Leon" > wrote in message
...

> Air does not "stick" to an airframe enough to change the ambient temperature
> of a given area no matter how small.

No, but everyone who has ever studied for their Private written knows that
the wake of an aircraft is accelerated down. So the passage of an aircraft
would cause a very temporary downward flow of air. Would the effect be enough
to noticeably change local temperatures? I doubt it; but who the hell am I?

[Capt. Geoffrey Thorpe]

"Chris W" > wrote in message
...
> My dad drives along the south side of OKC to work every day and his OAT in
> his car always goes a few degrees colder around the where the extended
> centerline for the runways would intersect the road. Then it goes right
> back up after he is through that area. He thinks this is because the
> airplanes are descending from very cold air and bringing down some of it
> with them. He has noted that this isn't always the case but it often is.
> You would think most of the traffic would be landing from the north since
> our winds are mostly from the south, but it seems like I see a lot of
> traffic coming in from the south, maybe because it is easier for the
> traffic from DFW to just come strait in.


If I were to guess (and it's just a guess) I would suspect that the long
open space along the runway allows the wind to blow a little faster (less
drag from buildings and stuff) and pulls down a little more cool air from
higher altitudes.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Kev]

On Apr 2, 5:43 pm, "Capt. Geoffrey Thorpe" <The Sea Hawk at wow way
d0t com> wrote:
> If I were to guess (and it's just a guess) I would suspect that the long
> open space along the runway allows the wind to blow a little faster (less
> drag from buildings and stuff) and pulls down a little more cool air from
> higher altitudes.

A similar sort of guess would be that it's the same effect as a sea
breeze. The runway surface heats up and causes a cool breeze towards
it.

Chris, is this in the morning or afternoon?

Kev

[Peter Dohm]

> > >> re spending money to figure that out. I thought that was common
> > >> knowledge.
> > >
> > > Well, sometimes things that are common knowledge are incorrect.
> > >
> > > Jose
>
> > Jose, you sound like your buddy MX. When I returned from luch today I
walked
> > from a concrete parking lot over about 10 feet of grass to enter the
> > building. I did not need airborne equipment to tell me it was warmer
over
> > the concrete than it was over the grass.
>
> Well, yeah, but I wouldn't use that to make the decision as to whether
> or not huge piles of money should be spent to combat global warming.
>
> I think we need something from traceable, calibrated instruments with
> error bars on the numbers, which is what hopefully the airplane is
> getting.
>
> --
> Jim Pennino
>
Just to add a little more "food for thought" to the Global Warming issue: I
recently heard another of those poorly attributed sotries on radio. In this
case, it seems that some of the Siberian reporting stations were
abandonned--so the subsequent data was merely compiled without them...

As to the original question, I presume that the road near the approach end
of the runway is simply in a less built-up area that the rest of Chris'
Dad's morning commute. That would be nothing new; there has been a very
noticeable change of temperature in less than a quarter mile--in that type
of transition--for as long as I can remember. With the windows open, you
can suddenly wonder if you should have brought a jacket...

Peter

[BT]

I would sooner think that it is the ground in the area... is there water or
a marshy area near there?

BT

"Chris W" > wrote in message
...
> My dad drives along the south side of OKC to work every day and his OAT in
> his car always goes a few degrees colder around the where the extended
> centerline for the runways would intersect the road. Then it goes right
> back up after he is through that area. He thinks this is because the
> airplanes are descending from very cold air and bringing down some of it
> with them. He has noted that this isn't always the case but it often is.
> You would think most of the traffic would be landing from the north since
> our winds are mostly from the south, but it seems like I see a lot of
> traffic coming in from the south, maybe because it is easier for the
> traffic from DFW to just come strait in.
>
> Anyway, any one here think it is really the case that the planes are
> causing the temperature to be lower on the approach end of the runway? I
> guess if he monitored the ATIS frequency to find out which runway was
> active when he drives by every day, he would have a better idea.
>
>
> --
> Chris W
> KE5GIX
>
> "Protect your digital freedom and privacy, eliminate DRM,
> learn more at http://www.defectivebydesign.org/what_is_drm"
>
> Gift Giving Made Easy
> Get the gifts you want &
> give the gifts they want
> One stop wish list for any gift,
> from anywhere, for any occasion!
> http://thewishzone.com

[tony roberts]

Is it colder at the approach end of a runway?

No.


--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[Jim Logajan]

tony roberts > wrote:
> Is it colder at the approach end of a runway?
>
> No.

But isn't it true, or so I've been told, that it is always cloudier over an
airport than the surrounding area? :-)

[flynrider via AviationKB.com]

Robert M. Gary wrote:
>
>I live near Sacramento where we have long periods of 100+ degree
>temps. The gov't has been doing research here on the affect of asphalt
>and roofs (not sure why) on temps. They fly a plane overhead in the
>afternoon with sensitive heat detecting equipment. They seem to
>believe the city is much hotter simply because of the pavement and the
>roofs.
>

Don't know why they'd be studying it in Sacramento. Here in Phoenix it has
long been known as the "Heat Island". Basically, asphalt, roofs and concrete
absorb much more heat than dirt or grass. The result is that this excess
heat is liberated slowly after the sun goes down and raises the overnight low
temperature in populated areas.

If you live in a rapidly expanding desert town long enough, it's easy to
see. When I moved here, there were about 1.5 million people in the metro
area. During the hottest part of the summer, overnight low temperatures
stayed in the mid to upper 80s. Nowadays, we have about 4 million people and
the overnight lows stay in the low to mid 90s at the peak of summer. Daytime
temperatures haven't shown any corresponding increase.

John Galban=====>N4BQ (PA28-180)

--
Message posted via AviationKB.com
http://www.aviationkb.com/Uwe/Forums.aspx/aviation/200704/1

[John Halpenny]

On Apr 2, 5:33 pm, "Vaughn Simon" >
wrote:
> "Marco Leon" > wrote in message
>
> ...
>
> > Air does not "stick" to an airframe enough to change the ambient temperature
> > of a given area no matter how small.
>
> No, but everyone who has ever studied for their Private written knows that
> the wake of an aircraft is accelerated down. So the passage of an aircraft
> would cause a very temporary downward flow of air. Would the effect be enough
> to noticeably change local temperatures? I doubt it; but who the hell am I?

What time of day does he go by? I could see the downwash mixing up
the air, and if there is a hot surface layer this could cool it.

As an example of downwash changing the temperature, I have heard
helicopter pilot stories about 'frost flights' at strawberry farms.
The task is to spend the night at the farm, and if the frost alarm
goes off in the wee hours you have to fly low over the fields in the
dark until the air is stirred up and the frost danger goes away. It
apparently is very effective in preventing frost damaged berries.

John Halpenny

[tony roberts]

> > Is it colder at the approach end of a runway?
> >
> > No.
>
> But isn't it true, or so I've been told, that it is always cloudier over an
> airport than the surrounding area? :-)


Now that IS true :)

Tony

--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[[email protected]]

On Apr 2, 9:18 pm, "John Halpenny" > wrote:
> On Apr 2, 5:33 pm, "Vaughn Simon" >
> wrote:
>
> > "Marco Leon" > wrote in message
>
> ...
>
> > > Air does not "stick" to an airframe enough to change the ambient temperature
> > > of a given area no matter how small.
>
> > No, but everyone who has ever studied for their Private written knows that
> > the wake of an aircraft is accelerated down. So the passage of an aircraft
> > would cause a very temporary downward flow of air. Would the effect be enough
> > to noticeably change local temperatures? I doubt it; but who the hell am I?
>
> What time of day does he go by? I could see the downwash mixing up
> the air, and if there is a hot surface layer this could cool it.
>
> As an example of downwash changing the temperature, I have heard
> helicopter pilot stories about 'frost flights' at strawberry farms.
> The task is to spend the night at the farm, and if the frost alarm
> goes off in the wee hours you have to fly low over the fields in the
> dark until the air is stirred up and the frost danger goes away. It
> apparently is very effective in preventing frost damaged berries.
>
> John Halpenny


This has been done with fixed-wing airplanes, too. An airliner
on approach can't help but drive down air from a couple hundred feet
up. Problem with that, of course, is that the OP says his dad notices
this on the drive to work, presumably in the morning, and the air
aloft will be warmer rather than colder at that time. The nocturnal
inversion is still in play in the morning, before the surface heats
up. It's that warmer air the helicopters or other craft are driving
down at night into the orchards or vineyards or citrus groves.

Dan

[Chris W]

I posted this and then got busy so I am just now reading the replies. I
will try to respond to most of the replies in this message.

Airport is KOKC (Will Rogers International)
The location where the temperature change is noticed is SW 104th Street
which is just a hair over 1 mile south of the runway 35L and 35R.

We weren't thinking so much that the temperature change was due to the
down wash of air following the plane as it was the fact that at 30,000
feet the plane mass (which is quite a bit in an airliner) becomes very
cold and as it moves through the warmer air at the the lower altitudes
near the airport, it absorbs the heat from the air and therefore leaves
it colder than it was.

I do suspect though that as at least one poster suggested it may be due
to the fact that there isn't much development out there. If you look at
the satellite map, you will see very little development for a long way
south.

Another reason my dad thought this might be at least partially caused by
the aircraft is the fact that sometimes it is warmer there. In that
case he was thinking that the planes had been sitting on the ground for
some time and most of the structure was at least as warm as the ambient
air, then with the engines putting out full power for about 3 miles
before they cross the road, would be generating a lot of heat. So if the
planes were departing on runway 17L or 17R, it wold tend to warm it up.

However it could just be due to what direction the wind was blowing.
South wind blowing over mostly farm land and the river a few miles
south. Keeping it cool and a north wind blowing over the city, keeping
it warmer.


--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
One stop wish list for any gift,
from anywhere, for any occasion!
http://thewishzone.com

[Chris W]

I forgot to mention, yes this is in the morning around 7 to 8 am.


--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
One stop wish list for any gift,
from anywhere, for any occasion!
http://thewishzone.com