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1-Hour Average Plots, Plasma and Magnetic Data Merged


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

Time span: 1974-12-10 to 1980-12-29


This data set consists of color plots of 1-h averages of solar wind and IMF (interplanetary magnetic field) parameters. The plots were made from data sets 74-097A-01C, 74-097A-09B, 76-003A-01C, and 76-003A-09B, which consist of a simplified format tape containing the merged solar wind plasma and magnetic field data from Helios A and B. The original data from which these merged tapes were made were provided by Rainer Schwenn and H. Rosenbauer (plasma) and F. Neubauer (magnetic field). Also included in this data set are derived parameters, such as energy flux and beta, obtained from algorithms prepared by J. W. Freeman at NSSDC. The pixels making up each plot are color coded to indicate the magnitude of each solar wind or IMF parameter, with only one parameter shown on each plot. The pixels are located on a grid of Carrington rotation number versus Carrington longitude of the subspacecraft point. Thus time progresses from right to left on a line, and from the top to the bottom of the picture. In this manner, approximately 6 years of data may be displayed on one plot. The resulting plots are easy to read, and rapid identification of features such as high speed streams, shocks, and sector boundaries is possible. Parameters displayed are solar wind bulk flow speed, radial component of proton temperature, proton number density, proton energy density (including flow and thermal energy), solar wind energy flux, rectangular components of the IMF in solar ecliptic coordinates, magnitude of the IMF, energy density of the IMF, beta (ratio of proton thermal energy density to IMF magnetic energy density), and the Mach number (ratio of the solar wind bulk flow speed to the Alfven velocity). The data are available as color prints or as 35-mm color slides. This data set is identically listed under identification numbers 74-097A-01D, 74-097A-09C, 76-003A-01D, and 76-003A-09C.

Alternate Names

  • 1-H Ave Plot, Plasma + Mag Merged


  • Space Physics: Heliospheric Studies


  • 74-097A-01D
  • 74-097A-09C

Additional Information



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



NameRoleOriginal AffiliationE-mail
Dr. John W. FreemanGeneral ContactNASA Goddard Space Flight Center
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