Extraterrestrial Radiation

Extraterrestrial radiation refers to solar energy reaching the top of Earth’s atmosphere before being attenuated by the atmosphere. It primarily consists of visible light and ultraviolet rays.

The extraterrestrial solar irradiance at the top of the atmosphere, I_0, is 1367 W/m².

The amount of extraterrestrial radiation received on a horizontal surface depends on the solar declination angle, hour angle, and Earth’s axial tilt. These factors determine the path length of sunlight through the atmosphere.

The solar declination angle is the angle between the equatorial plane and a line connecting the Earth’s center to the Sun. It affects how much solar energy reaches different latitudes.

The hour angle is the angular distance on the celestial sphere measured westward along the celestial equator from the meridian to the hour circle passing through a point. It helps determine the position of the sun in the sky.

Earth’s axial tilt causes different parts of the planet to receive varying amounts of solar energy throughout the year, leading to seasonal changes and affecting the distribution of extraterrestrial radiation.

Understanding extraterrestrial radiation is crucial for modeling climate systems, predicting weather patterns, and assessing solar energy potential. It helps in studying how solar energy interacts with the Earth’s atmosphere and surface.