Definition

Noun: - The rate at which radiant solar energy is received at the outer layer of the earth's atmosphere: It is a measure of the solar irradiance (power per unit area) incident on a plane perpendicular to the Sun's rays, just outside Earth's atmosphere, at Earth's mean distance from the Sun. Its value is approximately 1,361 watts per square meter.

Usage Examples

• Noun:
  • Scientists monitor the solar constant to detect long-term changes in the Sun's energy output.
  • The precise measurement of the solar constant is crucial for climate modeling.
  • Despite its name, the solar constant exhibits slight variations over time.

Advanced Usage

• "Variations in the solar constant": Refers to the small fluctuations in the measured value due to solar cycles and other solar phenomena.
  • Satellite data has revealed that the solar constant is not perfectly constant but varies slightly with the 11-year solar cycle.

Variants and Related Words

• Solar irradiance (n): A more general term for the power per unit area received from the Sun. The solar constant is a specific, averaged value of solar irradiance at a standard distance.
• Insolation (n): A term often used in climatology and meteorology to describe the solar radiation received by a given surface area over a period of time.

Synonyms

• Total solar irradiance (TSI): This is the modern, more precise term for the solar constant, acknowledging its variable nature.
• Extra-terrestrial solar flux: A technical synonym emphasizing the measurement is taken outside Earth's atmosphere.

Related Phrases

• "Measurements of the solar constant": A common phrase in scientific literature describing the act of quantifying this value.
  • Accurate measurements of the solar constant require instruments on satellites above the atmosphere.

Noun

1. the rate at which radiant solar energy is received at the outer layer of the earth's atmosphere