solar elevation angle derivations

1. solar elevation angle from solar zenith angle

   symbol	description	unit	variable name
   \(\alpha_{0}\)	solar elevation angle	\(deg\)	solar_elevation_angle {:}
   \(\theta_{0}\)	solar zenith angle	\(deg\)	solar_zenith_angle {:}

   The pattern : for the dimensions can represent {time}, or no dimensions at all.

   \[\alpha_{0} = 90 - \theta_{0}\]