Sunrise

Sunrise is the moment the upper edge of the sun first appears on the horizon in the morning, and also the broader process of the solar disc crossing the horizon; the sun does not truly rise, the effect comes from the rotation of Earth itself. Its colors come from how sunlight scatters through the atmosphere: air molecules and airborne particles scatter shorter blue and green wavelengths away through Rayleigh and Mie scattering, leaving the longer orange and red wavelengths that reach the eye, an effect made stronger at sunrise because the path of light through the atmosphere is longest at that time. Atmospheric refraction also bends light from the sun so it appears above the horizon slightly before it is geometrically there, while flattening and widening its visible disc.