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Merged Plasma and Magnetic Field (1-Min) Geotail Data (Inc. Ephemeris Data)


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1982-12-01 to 1983-12-01


This data set (also archived as 78-079A-02P) contains the merged plasma and magnetic field data for the geotail phase of the ISEE-3/ICE mission. Each data record contains the date and time, the spacecraft position in GSE and GSM coordinates, the electron density (per cm**3), bulk flow speed (km/s), temperature (K) and flow azimuth (degrees, with zero corresponding to anti-sunward flow, +90 to dawnward flow and -90 to duskward flow), the magnetic field magnitude (nT), latitude and longitude in GSE coordinates (degrees; positive latitude northward, and in contrast to the plasma data, longitude=0 corresponds to sunward directed field, +90 is duskward, and -90 is dawnward), the magnetic field standard deviation, and a flag indicating the magnetotail region. Depending on the spacecraft mode, the plasma samples occur at 84-second or 12-second intervals. Times associated with each data point are the beginning of the 3-second data collection interval. The Vector Helium Magnetometer produced six vector measurements per second that were subsequently averaged over one minute intervals before merging with the plasma data. Merging was accomplished by associating the nearest 1 minute field average with each plasma sample. When plasma data occur every 84 seconds, an occasional one-minute field average will be missing; when plasma data occur every 12 seconds, identical field values will often occur in successive records. Data gaps occur when either plasma or magnetic field data are missing. This data set is the digital version of the plots published as "1983 Tail-Era Data Series," Volumes 1 and 2, NSSDC/WDC-A-R&S 90-11 and 90-12. The full set of geotail interval electron plasma data from ISEE-3/ICE are archived as data set 78-079A-01M. Magnetic field data at 1-minute and 3-second resolution for the geotail interval are archived as data set 78-079A-02O.

Data are available online at

Alternate Names

  • Plasma & B-Field(1-m) Tail Data


  • Space Physics: Heliospheric Studies


  • 78-079A-01Q
  • 78-079A-02P

Additional Information



Questions and comments about this data collection can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Dr. John L. PhillipsData ProviderLos Alamos National
Mr. Robert M. CandeyGeneral ContactNASA Goddard Space Flight
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