I think you will find, Joe, that the Theta-A you refer to is actually
straight Theta, or the potential temperature. Other suffixes to theta are
Theta-w for wet bulb potential temperature, Theta-V for Virtual potential
temperature, Theta-E for equivalent potential temperature and Theta-L for
liquid water potential temperature.

--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.btinternet.com/~wokingham.weather/wwp.html
"Joe Egginton" wrote in message
...
Could someone tell me what does the Theta A index measure and is used for?

--
Joe
Wolverhampton
175m asl