Daily Solar Ultraviolet Irradiance Measurements from SME Satellite

NASA's Solar Mesosphere Explorer satellite provides daily average solar irradiance data in the ultraviolet spectrum from 115.5 to 302.5 nm. The dataset includes improved solar Lyman-alpha flux corrections for wavelengths at 120, 121, and 122 nm. Data was collected by the SCIOPS organization and normalized to a rocket experiment from May 17, 1982.

Use Cases

• Analyzing daily solar irradiance averages across the 115.5-302.5 nm spectral range for space weather monitoring.
• Applying corrections to the improved solar Lyman-alpha flux data at 120, 121, and 122 nm for instrument calibration studies.
• Studying relative annual solar variability trends with the noted +/- 2% per year relative accuracy metric.
• Comparing absolute flux measurements normalized to the May 17, 1982 rocket experiment for long-term data validation.

Strengths

• Spectral resolution of 1 nm for detailed ultraviolet analysis.
• Includes specific corrections for instrument wavelength calibration errors at three Lyman-alpha wavelengths.
• Absolute flux normalized to a known experiment (May 17, 1982 rocket).

Limitations

• Absolute flux accuracy is limited to +/- 15%.
• Investigators explicitly advise against using this data for extracting long-term solar variability.
• Relative accuracy is no better than +/- 2% per year.

Provenance

Source

Solar Mesospheric Explorer (SME) Ultraviolet Spectrometer, via NASA Earthdata.

Collection Method

Measurements from an onboard solar spectrometer, processed into daily averages adjusted to 1 AU.

Geography

Space-based measurements of the Sun.