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Advanced Composition Explorer Level 2 SWEPAM 64-sec Solar Wind Ion Data, HDF


Availability: At NSSDC, Ready for Electronic Access

Time span: 1998-01-23 to 2004-05-05


This data collection contains Level 2 data files in NCSA Hierarchical Data Format (HDF) from the Solar Wind Electron, Proton and Alpha Monitor (SWEPAM) experiment on the Advanced Composition Explorer (ACE) spacecraft. Each file contains solar wind ion data from one Bartel interval of 27 days at a time resolution for individual records of 64 seconds. Each record contains solar wind proton density (cm-3), radial component of the proton temperature (Kelvin), alpha/proton density ratio, and proton speed (km/s). The proton velocity vector components (km/s) are given in Geocentric Solar Ecliptic (GSE), Heliographic (RTN), and Geocentric Solar Magnetospheric (GSM) coordinates. The ACE spacecraft position is included in GSE and GSM coordinates. A data value of -9999.9 indicates bad or missing data for the given time period. Release notes on Level 2 processing are given in the text file swepam_release_notes.txt.

This collection is available on-line at:

A fully reprocessed version of this data set from the ACE Science Center was placed on-line at this site as of Sept. 14, 2004.

Alternate Names

  • SWEPAM Level-2 64-s Ion Data,HDF


  • Space Physics: Heliospheric Studies


  • 97-045A-07A

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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