Adiabatic lapse rate

In article ,
S Green wrote:

"Everett M. Greene" wrote in message
...
Does the lapse rate equation hold in all cases? I was recently
wondering what kind of temperature would be reached at 35 Kft
over Arctic Canada in January. It seemed that the lapse rate
equation would lead you to expect temperatures that would be
causing nitrogen and carbon dioxide to be condensing which
doesn't seem likely.

A few years back, my (then) 4th grade son did his science fair project on how
temperature changes with altitude. Over the course of a year, and
probably a dozen or more family flights, he measured the OAT as a function
of altitude during our climb-outs and descents. He got data from sea level
up to 14,000. Amazingly enough, it averaged out to almost exactly
2 deg C/1000'. He noted that the greatest deviations from that occurred
very close to the ground (within 2000' AGL) and when we were in clouds (IMC).

Now, our Cherokee 6 can't climb up to FL 350, so I have no personal
experience with how high the standard lapse rate holds. However, my son
will tell you that for a clear day, above 2000' AGL, it seems to hold
very very well.

Oh....and he got first place for his science project. I couldn't be a
prouder pilot-papa.

-- Dane

"Peter" wrote in message
...

(Dane Spearing) wrote

Now, our Cherokee 6 can't climb up to FL 350, so I have no personal
experience with how high the standard lapse rate holds. However, my son
will tell you that for a clear day, above 2000' AGL, it seems to hold
very very well.

He got lucky. I can't remember a flight here (UK) where the lapse rate
was anything like 2C/1000ft.

Yesterday, +10C on the ground, +8C at 5000ft.

That might have been because there was an inversion from the ground up to
say 2000 ft, a higher temperature that ground level.

Why dies everyone think that the standard lapse rate is a
meteorological term?

It's not.


On Fri, 26 Oct 2007 17:59:15 +0100, "S Green"
wrote:


"Peter" wrote in message
.. .

(Dane Spearing) wrote

Now, our Cherokee 6 can't climb up to FL 350, so I have no personal
experience with how high the standard lapse rate holds. However, my son
will tell you that for a clear day, above 2000' AGL, it seems to hold
very very well.

He got lucky. I can't remember a flight here (UK) where the lapse rate
was anything like 2C/1000ft.

Yesterday, +10C on the ground, +8C at 5000ft.

That might have been because there was an inversion from the ground up to
say 2000 ft, a higher temperature that ground level.

wrote in message
...
Why dies everyone think that the standard lapse rate is a
meteorological term?

It's not.


You think it is a cooking term?
Maybe medical, as in "I let my medical lapse".

Al G

It is used to model the standard atmosphere, certainly is a
scientific term used in physics, which applies to
meteorological study. It has an application to actual
flight by using terms such as ISA+20



"Al G" wrote in message
...
|
| wrote in message
| ...
| Why dies everyone think that the standard lapse rate is
a
| meteorological term?
|
| It's not.
|
|
| You think it is a cooking term?
| Maybe medical, as in "I let my medical lapse".
|
| Al G
|
|

Environmental lapse rate is a meteorological term.

Adiabatic lapse rates are meteorologocal terms.

Standard lapse rates are an invention of engineers to enable them to
compare aircraft performance.




On Mon, 29 Oct 2007 08:40:05 -0700, "Al G"
wrote:


wrote in message
.. .
Why dies everyone think that the standard lapse rate is a
meteorological term?

It's not.


You think it is a cooking term?
Maybe medical, as in "I let my medical lapse".

Al G