Is it colder at the approach end of the runway?

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

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.