Solar irradiance: total and spectral and its possible variations
Applied Optics
|February 19, 2010
Summary
Accurate solar irradiance measurements are crucial for understanding solar-weather relationships. Current data has high uncertainties, highlighting the need for improved solar monitoring, like NASA
Area of Science:
- Solar physics and atmospheric science.
- Space-based solar monitoring.
Background:
- Current standard values for solar constant and extraterrestrial solar spectral irradiance have high uncertainties.
- Existing data on solar constant variability is conflicting and inconclusive.
- Variability of solar spectral irradiance remains largely unknown.
Purpose of the Study:
- To review the current state of knowledge on solar irradiance.
- To present accepted standard values and discuss their uncertainties.
- To emphasize the need for precise solar irradiance variation data due to potential sun-weather links.
Main Methods:
- Review of existing NASA/ASTM standard values for solar irradiance.
- Discussion of data limitations and uncertainties.
- Overview of NASA's solar monitoring programs, including the proposed Solar Energy Monitor in Space (SEMIS) experiment.
Main Results:
- Accepted NASA/ASTM standard values for solar constant and spectral irradiance are presented.
- Significant uncertainties exist in current solar irradiance data.
- Conflicting and inconclusive data exists regarding solar constant variability.
Conclusions:
- There is a critical need for more precise measurements of total and spectral solar irradiance variations.
- Improved solar monitoring is essential for understanding potential sun-weather relationships.
- The proposed Solar Energy Monitor in Space (SEMIS) experiment aims to address these measurement gaps.
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