SOR4XPSD_HIGH: Daily Solar Extreme Ultraviolet Irradiance Model

NASA's SORCE mission provides this Level 4 dataset of modelled solar spectral irradiance in the extreme ultraviolet (XUV) range. It contains daily averages of irradiance from 0.1 to 39.9 nm at 0.1 nm resolution, derived from SORCE XPS and GOES XRS instrument data. The model includes scale factors for quiet-sun, active-region, and flare components, along with associated uncertainty estimates.

Use Cases

• Modeling solar EUV input for atmospheric and ionospheric studies based on the daily MODELFLUX array.
• Analyzing flare characteristics and plasma temperatures using the FMTEMP and flare scale factor columns.
• Assessing model and measurement uncertainty for spectral irradiance data via the ERR_ABS and ERR_MEAS variables.
• Investigating long-term solar activity variations using daily quiet-sun and active-region scale factors (XPS_QS, GOES_AR).

Strengths

• Provides high spectral resolution (0.1 nm) data across the scientifically critical 0-40 nm extreme ultraviolet range.
• Integrates data from two major solar observation instruments (SORCE XPS and GOES XRS) for model construction.
• Includes explicit uncertainty estimates for both model accuracy (ERR_ABS) and measurement precision (ERR_MEAS).
• Covers the entire SORCE mission lifetime, offering a continuous multi-year time series.

Limitations

• Key metadata such as row count, file size, and specific license terms are missing or conflicting across platforms.
• The most recent update date is inconsistent, with one source showing 2026 (likely a placeholder) and another showing 2020.
• Data is provided as daily averages, which may not capture sub-daily transient solar events.

Provenance

Source

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

Collection Method

Modelled data based on calibrated SORCE XUV Photometer System (XPS) measurements and GOES XRS-derived flare plasma temperatures, using CHIANTI reference spectra.

Time Range

Covers the entire SORCE mission duration (specific years not provided in input).

Freshness

Last updated dates conflict: 2026-04-09 (datagov, potentially a placeholder) and 2020-02-24 (nasa_earthdata).

Geography

Solar observations; no specific Earth geography.