A term used to describe the average quantity of solar insolation received by a horizontal surface at the edge of the Earth's atmosphere. This value is approximately 1370 Watts per square meter.

  The average amount of solar radiation that reaches the earth's upper atmosphere on a surface perpendicular to the sun's rays; equal to 1353 Watts per square meter or 492 Btu per square foo [..]

The average amount of solar radiation reaching a planet; usually expressed in watts (energy per unit time) per square meter. For Earth, the solar constant equals 1,372W/m2. Each planet has a unique so [..]

The average amount of solar radiation reaching a planet; usually expressed in watts (energy per unit time) per square meter. For Earth, the solar constant equals 1,372 W/m2. Each planet has a unique s [..]

the amount of energy received per unit area from the sun over a given period of time.

The strength of sunlight; 1353 watts per square meter in space and about 1000 watts per square meter at sea level at the equator at solar noon. It increases at higher altitudes.

The quantity of radiant solar heat, 1.94 calories per minute, received per square centimeter of the earth's surface.

The rate at which solar energy is received just outside the Earth's atmosphere on a surface that is normal to the incident radiation and at the mean distance of the Earth from the sun. The current value is 0.140 watt/cm2.

The solar constant (S0) is the amount of incoming solar electromagnetic radiation per unit area at the mean Earth-Sun distance, measured on the outer surface of the Earth's atmosphere, in a plane [..]

Aka total solar irradiance. The constant expressing the amount of solar radiation reaching the Earth from the sun, approximately 1370 watts per square meter. It is not, in fact, truly constant and var [..]

although not strictly constant, this number is the amount of solar power flux

The total radiant energy received vertically from the Sun, per unit area per unit of time, at a position just outside the Earth’s atmosphere when the Earth is at its average distance from the Sun. Radiation at all wavelengths from all parts of the solar disk is included. Its value is approximately 2.00 cal cm-2 min-1 = 1.37 kW m-2 and varies slight [..]

The average amount of solar radiation reaching a planet; usually expressed in watts (energy per unit time) per square meter. For Earth, the solar constant equals 1,372W/m2. Each planet has a unique solar constant depending on its distance from the Sun.

The radiation arriving from the sun at the edge of the Earth's atmosphere. The accepted value is about 1350 watts

The flux of solar radiational energy falling on a surface that is positioned at the top of the atmosphere and oriented perpendicular to the solar beam when Earth is at its average distance from the sun.

Total solar power received by a surface one meter square, perpendicular to the solar radiation, at a distance of 1 AU (1366.1 W m-2).

The amount of incoming solar radiation per unit area, measured on the outer surface of Earth's atmosphere, in a plane perpendicular to the rays.

 The amount of energy received per unit area from the sun over a given period of time.