Re: Hot air rising and automobile thermometers

[Leigh Palmer <palmer@SFU.CA>]

At 17:20 -0700 7/23/99, I wrote:

> The "common wind" referred to here is called the "geostrophic" wind.
> Explaining why it flows parallel to the isobars when driven by the
> pressure gradient is a good exercise for the physicist, unless his
> religion forbids belief in the Coriolis force. It also gives new
> meaning to the term "equilibrium". (The equilibrium is established
> between the pressure gradient force and the Coriolis force in the
> frame of reference which moves with the wind.)

I got that a little bit wrong. The proper frame is the frame fixed
to the Earth, of course. There can't be a Coriolis force acting on
the air in a frame where the air isn't moving! The equilibrium
results in the air moving with constant velocity (in the local
sense).

I'll get some sleep tonight.

Leigh