Supposedly I studied this in college and, if I correctly recall the
class where they discussed the standard atmosphere, which is of course
based on the atmosphere that we observe, at sea level the temperature
goes down as altitude increases until it stops changing. Then it stays
the same for a while. Then it goes up for a while. Then it stays the
same for a while. Then it goes down for a while, and then stays the
same for a while, and then it goes up and keeps going up and up and up.
At that point, though, you've got less than a thousand or so atoms per
liter, so it's not real clear what "temperature" means.
I wouldn't say that the density and pressure work to raise the
temperature, more that the mechanisms for what drives the temperature
change as you go up in altitude. For example, at very high altitudes,
there are more ways to get energy into the molecules that make up air,
but it's harder to get the energy because the density is so low. The
pressure and density decrease uniformly with increases in altitude,
which is why you can talk about "pressure altitude" and "density
altitude" but not "temperature altitude", and of course the temperature,
pressure, and density are all related by air's equation of state.
By the way, the "standard atmosphere" is based on something called
"geopotential altitude" which redefines the foot (well, actually meter)
of altitude to be such that the acceleration due to earth's gravity is
constant. That means that a certain integral has a closed-form solution
and there's a known conversion and fairly simple to the more usual
"geometric altitude." I found that kind of interesting.
On 3/21/19 1:24 PM, john Parmalee via BVARC wrote:
Apparently there it a point the density and pressure work to raise the
temperature. It's one of those this that is linear until it's not.
John Parmalee
[email protected] <mailto:[email protected]>
281-380-3811
K5VGM WI2XLJ
In a message dated 3/21/2019 1:16:56 PM Central Standard Time,
[email protected] writes:
i would have thought as the balloon gets higher with thinner air
that the temperature would get colder. you say it goes up.
interesting. i may need to take a look at that. neat experiment.
73...bruce
Sent from my iPhone
On Mar 21, 2019, at 1:10 PM, john Parmalee via BVARC
<[email protected] <mailto:[email protected]>> wrote:
*Especially for those that won’t be able to make it to the Houston
HamFest this weekend.*
*Two Balloon launches with ham gear on board. You can participate. *
*Live video of both launches **https://zoom.us/i/2815436502*
*9:30 AM BLT-51 will launch*
*You can track with **http://APRS.fi <http://aprs.fi/>** search
**the call W5ACM-10. *
*You can Google APRS to find the site.*
*BLT-51 will be a floater, designed to be tracked via APRS and
glide across the country, and hopefully even further. The last one
went to Florida in about six hours.*
*Around 1:00 PM another launch BLT-52*
*BLT-52 is a “popper.” **Designed to go up as high as possible and
burst, also to be tracked via APRS. Last August a popper flew to
nearly 100,000 feet. “To the edge of space.”*
*W5ACM Cross-band FM repeater will be in board with with *
*Input on 147.435 MHz **ß**-----**à** Output on 446.550 MHz no
tone, open to all to work *
*A WB8ELK APRS Tracker on 144.390 MHz with the call W5ACM-11 will
be on board.*
*You can track at **http://APRS.fi <http://aprs.fi/>**search for
W5ACM-11*
*On board also the AB5SS Smart Beeper**on 10 and 20M 14.318 &
28.322 mHz, the temperature in CW call sign and BL-52. Wach as the
balloon passes through 60,000 feet the Temperature to rise. *
*The video will also be recorded for later playback as well, and
depending on the size of the captures, they will either be in the
groups.io <http://groups.io> FILES area
https://groups.io/g/Ham-Radio-Tech-Notes/files** , or my
website.K5WH.net <http://website.K5WH.net>*
.
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_______________________________________________
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Radio,Radio,Radio We are a radio Club!
Talk it up! On the air about every event, every meeting, every
net, every time, talk about the club, ham fests, events and people.
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_______________________________________________
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Radio,Radio,Radio We are a radio Club!
Talk it up! On the air about every event, every meeting, every net, every time,
talk about the club, ham fests, events and people.
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Message delivered to [email protected]
--
Jonathan Guthrie
ARS KA8KPN
_______________________________________________
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Radio,Radio,Radio We are a radio Club!
Talk it up! On the air about every event, every meeting, every net, every time,
talk about the club, ham fests, events and people.
[email protected]
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