Flatness of the setting Sun

摘要

The flattened rim of the setting or rising Sun is. a consequence of atmospheric refraction. We study the flatness as a function of the Sun's inclination angle, the observation height, and the meteorological conditions characterized by pressure, temperature, and lapse rate using a standard model of the atmosphere. Numerical calculations are compared with simple observations. Extreme and unusual situations are revealed. (C) 2003 American Association of Physics Teachers. [References: 12]