Solar zenith angle minutes of arc, which is less than the apparent angular radius of the sun. The formula also neglects the effect of atmospheric refraction. Sunset and sunrise occur (approximately) when the zenith angle is 90°, where the hour angle "h" satisfies Precise times of sunset and sunrise occur when the upper limb of the Sun appears, as refracted by the atmosphere, to be on the horizon. A weighted daily average zenith angle, used in computing the local albedo of the Earth, is given by where "Q" is the instantaneous insolation. For example, the solar elevation angle is : An exact calculation
Nambu Type 90 than the Imperial Army's Type 10 for a few good reasons. First, they were made in lower numbers than the Army type. Second, they were usually issued to ships and Naval aircraft and were lost when they were destroyed or sank. Third, Soldiers and Marines who found flare guns on the battlefield often threw them away, as they were not seen as collectable as pistols, rifles, or knives. In Hollywood movies (like "Demolition Man (1993)" and "Waterworld (1995)"), the Type 90 is used erroneously as a stand-in for a futuristic shotgun pistol. Nambu Type 90 The Nambu Type 90 was