solar constant

American  

noun

1. the average rate at which radiant energy is received from the sun by the earth, equal to 1.94 small calories per minute per square centimeter of area perpendicular to the sun's rays, measured at a point outside the earth's atmosphere when the earth is at its mean distance from the sun.

---

solar constant British  

noun

1. the rate at which the sun's energy is received per unit area at the top of the earth's atmosphere when the sun is at its mean distance from the earth and atmospheric absorption has been corrected for. Its value is 1367 watts per square metre

---

solar constant Scientific  

1. The average amount of solar radiation received by the Earth's atmosphere, per unit area, when the Earth is at its mean distance from the Sun. It is equal to 1370 watts per square meter. Solar radiation varies with the Earth's distance from the Sun and with the appearance or decay of sunspots.

---

Etymology

Origin of solar constant

First recorded in 1865–70

Example Sentences

Estimated past changes in solar irradiance were prescribed as a change in the solar constant S whereas forcing by volcanic aerosols was prescribed as a change in the surface albedo a.

From Salon

Estimated past changes in solar irradiance were prescribed as a change in the solar constant S whereas forcing by volcanic aerosols was prescribed as a change in the surface albedo a.

From Scientific American

"That's distinctly different from the simpler simulations where you just turn down the solar constant, which has been done in many studies," he said.

From Scientific American

The station at Calama yields about 250 determinations of the solar constant each year, and the Mount Wilson station about half that number.

From Project Gutenberg

It would do so because at times of abundant sunspots the sun in our own day has a higher solar constant than at times of milder activity.

From Project Gutenberg