Re: solar calculation

[Leigh Palmer <palmer@sfu.ca>]

> How can we calculate the angle of the sun, above the horizon, at a
> specific location ( a city for example) on the dates of Dec 21st, March
> 21st, June 21st, and Sept 21st?

I'll assume you mean at local solar noon, the time when its altitude, A,
(the angle above a true horizon) is maximum for that day. The obliquity
of the ecliptic, I, is approximately 23-1/2 degrees. For an observing
location at latitude L, these quantities are related by:

      Date              formula

 Summer solstice        A = I + L

 Equinoxes (both)       A = I

 Winter solstice        A = I - L

Leigh