Calculates the angle between the sun's rays and the vertical (zenith) direction. A zenith angle of 0° means the sun is directly overhead, while 90° means the sun is at the horizon. Implements Equation 6 from Appelbaum & Flood (1990).
Calculates the angle between the sun's rays and the vertical (zenith) direction. A zenith angle of 0° means the sun is directly overhead, while 90° means the sun is at the horizon. Implements Equation 6 from Appelbaum & Flood (1990).