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ACE SEPICA 27-Day Particle Fluxes, ASCII


Availability: At NSSDC, Ready for Electronic Access

Time span: 1997-10-07 to 2002-08-23


This data collection contains 27-day (Bartels solar rotation) Level 2 data in ASCII text format from the Solar Energetic Particle Ionic Charge Analyzer (SEPICA) intrument on the Advanced Composition Explorer (ACE) spacecraft. This data set includes all measurements from solar quiet and active periods. The one data file covers all 27-day Bartels intervals of solar rotation within the present data set. Data records include 27-day time averages of H, He, C, O, Ne, Mg, Si, and Fe ion fluxes in units of particles/(cm2*sr*sec*Mev/nucleon). There are three energy channels for H ions at 0.7 - 3 MeV, eight for He at 0.4 - 2 MeV/nucleon, seven for C at 0.3 - 12 MeV/n, six for O at 0.05 - 7.2 MeV/n, four for Ne at 0.6 - 7.2 MeV/n, four to Mg at 0.8 - 6.0 MeV/n, four for Si at 0.8 - 5.2 MeV/n, and five for Fe at 0.1 - 3.1 MeV/n. Two of the He channels include contributions from a Am-241 calibration source in SEPICA and are dominated by source events during quiet times. Availability of specific ion and energy channels depends on instrument mode. A data value of -999.9 indicates bad or missing data for the given time period. The number of counts is also given from which the statistical uncertainties can be calculated. Statistical flux uncertainties are computed from flux/sqrt (N), where N is the number of counts or events during the averaging period. Current release notes on Level 2 processing are given in the text file sepica_release_notes.txt, and sepica_energy_bands.txt defines the energy ranges and mean energies for each data channel.

This collection is available on-line at:

Alternate Names

  • SEPICA Level-2 27-Day Flux, ASCII


  • Space Physics: Heliospheric Studies


  • 97-045A-04H

Additional Information



Questions and comments about this data collection can be directed to: Dr. John F. Cooper



NameRoleOriginal AffiliationE-mail
Dr. Andrew J. DavisGeneral ContactCalifornia Institute of
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