SORCE SOLSTICE: Daily Solar MgII Core-to-Wing Ratio Measurements

NASA's SORCE SOLSTICE instrument provides daily-averaged measurements of the magnesium II core-to-wing ratio, a key index for solar activity. The data is stored in a tabular ASCII text file with columns for calendar date, Julian Day, the core/wing ratio, and its absolute uncertainty. This dataset supports the study of solar variability and its influence on Earth's upper atmosphere.

Use Cases

• Tracking long-term solar activity cycles based on the daily MgII core-to-wing ratio.
• Calibrating or validating solar models using the resolved Mg-II doublet measurements at 0.1 nm spectral resolution.
• Analyzing correlations between solar irradiance indices and atmospheric phenomena using the time-series of daily averages.

Strengths

• Data originates from the NASA SORCE mission's SOLSTICE instrument, a dedicated solar spectral irradiance monitor.
• Spectral resolution of 0.1 nm allows the Mg-II doublet to be fully resolved and modeled.
• Data is provided in a simple, accessible tabular ASCII format readable by spreadsheet applications.

Limitations

• Key metadata such as row count, file size, and precise temporal coverage is missing from all sources.
• Source platforms show a conflict in the 'last updated' date (2026 vs. 2020), casting doubt on metadata freshness.
• The license is ambiguously listed as 'other-license-specified' on Data.gov, requiring further investigation for reuse.

Provenance

Source

National Aeronautics and Space Administration (NASA), SORCE mission, SOLSTICE instrument.

Collection Method

Measurements taken during each daytime orbit portion (15 per day) via complete (30-minute) or quick (5-minute) solar spectrum scans.

Time Range

The length of the SORCE SOLSTICE measurement period (specific dates not provided in input).

Freshness

Last updated dates conflict: Data.gov lists 2026-04-09, while NASA Earthdata lists 2020-02-24.

Geography

Solar observations from space; no terrestrial geography.