Aviation Weather Class 1

My flight school is owned by a CFI who is a weather guru with many years as a military aviation meteorologist. He requires all students in the flight school to take his aviation weather class. Tonight was class #1 of 2.

Tonight we covered weather formation theory: what happens to heated air, conditions for stability, adiabatic heating and cooling, temperature lapse rates, effects of the solar insolation,  layers of the atmosphere, moisture changes of state, cloud formation & types, atmospheric circulation, details of how highs and lows affect weather movement, Coriolis effects, and all kinds of fog.

My favorite part was radiosondes/dropsondes and the data interpretation slides. Brings me back to the days of my bachelor’s degree capstone project. I built a UV based ozone detector designed to fly on a weather balloon. We released 3 balloons that year, refined the process/equipment along the way (see page 5 o‎f http://daytonabeach.erau.edu/coas/physical-sciences/news-events/newsletters/EP_Newsletter_Spring_2009.pdf‎. Yes, we put a satellite on top of our Christmas tree). Anyways, radiosonde data: it’s really cool how much you can tell about the atmosphere from humidity vs temperature/altitude plots.

Temperature inversion slides were made much more interesting by the fact Fairbanks is currently sitting in such a layer. It was slightly lower than -30F all day but if you go up the in-town ski slope, temperatures were reported at +40F. The inversion layer’s height has been visible all day via smoke/condensate:

Fairbanks Temperature Inversion is visible. Power plant output rises only slightly before leveling off and returning to the ground. [http://seagrant.uaf.edu/news/01ASJ/12.14.01bad-air.html]
An example picture: Temperature inversion interface can be visible! Fairbanks power plant output rises only slightly before leveling off. [http://seagrant.uaf.edu/news/01ASJ/12.14.01bad-air.html]

The flat layer tops were still visible from the airport tonight. A lot of Fairbanks residents still use wood stoves in town which makes for fantastic visuals, hundreds (thousands?) of smoke trails as you look out over town.

Something really cool from my geophysical fluid dynamics class today: you can calculate the vertical temperature gradient (departure from the adiabatic gradient) if you know the wind speed and wavelengths of the perturbation of the temperature interface.

class notes

[Courtesy B. Wu]
Waves at today’s Fairbanks temperature inversion boundary [Courtesy B. Wu]
I may update this post with actual calculated numbers (on Friday after I verify I did the math correctly).


Random cool thing I found: Interplanetary Cessna 172!

What would happen if you tried to fly a normal Earth airplane above different Solar System bodies?

Here’s what happens when an aircraft is launched above the surface of the 32 largest Solar System bodies:

Here’s what happens when an aircraft is launched above the surface of the 32 largest Solar System bodies.
Here’s what happens when an aircraft is launched above the surface of the 32 largest Solar System bodies. [http://what-if.xkcd.com/30/]

While I’ve not had time to personally validate all their claims, the statements look legit. More detailed explanations available on their page, http://what-if.xkcd.com/30/


If you’ve wondered why there haven’t been any posts in forever – it is because I haven’t been able to fly since Nov. 4. Lots of little reasons why (mostly weather related). It’s all documented with some great aurora photos; will be posted when I next get to fly.


2 thoughts on “Aviation Weather Class 1

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