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Advanced Composition Explorer Level 2 ASCII Magnetic Field Data, 27-day Scalar


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1997-12-27 to 2000-10-17


This data collection contains Level 2 data files in ASCII format from the magnetometer experiment on the Advanced Composition Explorer (ACE) spacecraft. Each file contains averages for one Bartel interval of 27 days. Only the scalar magnitudes of the magnetic field are given, since longer time averages of vector components and the associated angles are not meaningful. Other parameters include the variance of the scalar magnitude. The fraction of the averaging interval during which there was good quality data, and the number of 16-sec intervals (1) used to generate the average, are also included. Errors in magnetic field parameters are generally less than 0.1 nT. Spacecraft position is provided in GSE coordinates. Data values of -999.9 indicate bad or missing data for the given time period; this value is also used to fill the fields for vector and angle parameters not provided at this time resolution. Level 2 format documentation and release notes on processing are respectively included in the text files mag_l2desc.txt and mag_release_notes.txt.

This collection is available on-line at:

Alternate Names

  • MAG Level 2 ASCII,27-day Scalar


  • Space Physics: Heliospheric Studies


  • 97-045A-09J

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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