Initial solar irradiance determinations from nimbus 7 cavity radiometer measurements

Area of Science:

• Earth Science
• Space Science
• Atmospheric Science

Background:

• Accurate measurement of the solar constant is crucial for climate modeling and understanding Earth's energy balance.
• The Nimbus 7 satellite, equipped with the Earth Radiation Budget Experiment (ERBE), was launched to provide continuous solar radiation data.

Purpose of the Study:

• To present preliminary findings on the solar constant derived from early Nimbus 7 ERBE data.
• To quantify the short-term variability of solar irradiance during the measurement period.

Main Methods:

• Utilized data from the Earth Radiation Budget Experiment (ERBE) on the Nimbus 7 satellite.
• Analyzed solar radiation measurements collected between November 16, 1978, and May 15, 1979.
• Calculated the mean solar constant and its root-mean-square deviation.

Main Results:

• The preliminary mean solar constant was determined to be 1376.0 watts per square meter (W/m²).
• Observed variability in solar radiation measurements was minimal, with a root-mean-square deviation of +/- 0.73 W/m² (+/- 0.05%).

Conclusions:

• The initial ERBE data suggest a stable solar constant within the observed period.
• These findings provide a baseline for long-term solar irradiance monitoring and climate studies.