ACE SIS Solar and Galactic Particle Flux Measurements

27-day Bartels Rotation periods organize energetic particle flux data from the Advanced Composition Explorer's Solar Isotope Spectrometer. The dataset provides time-averaged fluxes for elements from He to Fe across eight energy ranges, measured in particles/(cm2 Sr sec MeV/nucleon). The instrument was developed by SCIOPS to measure isotopic composition during solar events and quiet times.

Use Cases

• Model solar particle event intensity by correlating He, C, O, and Fe flux time-series across 256-second, hourly, and daily averages.
• Identify isotopic signatures of anomalous cosmic rays by analyzing Ne, Mg, and Si flux ratios during solar quiet times.
• Analyze the correlation between solar rotation (27-day periods) and the temporal evolution of particle fluxes for elements like N and S.
• Compare energy spectra of different nuclei (He to Fe) across the eight instrument-defined energy ranges to study acceleration mechanisms.

Strengths

• Large geometry factor of ~40 cm2-sr for improved particle collection.
• Provides mass resolution data during high-flux solar particle events.
• Flux data available for 9 specific elements (He, C, N, O, Ne, Mg, Si, S, Fe).
• Time-averaged data provided at four resolutions: 256-second, hourly, daily, and 27-day periods.

Limitations

• Flux data is limited to 9 elements, not the full Z=2 to 28 range the spectrometer is designed for.
• Energy ranges differ for each element, complicating direct cross-element spectral comparisons.
• Temporal coverage and dataset size (row count) are unspecified.

Provenance

Source

Advanced Composition Explorer (ACE) spacecraft Solar Isotope Spectrometer (SIS).

Collection Method

Instrument measurements of energetic charged particle fluxes, processed to Level 2 time-averaged data.

Time Range

Data organized into consecutive 27-day Bartels Rotation periods.