The readme for this hourly solar wind magnetic field data. This data set was created at NSSDC by combining the hourly, all-orbit-phases data set (73-078A-01R) with IMP 8 bow shock crossing information to produce this hourly, solar-wind-only data set. This data set has annual files of hourly IMP 8 magnetic field averages, in ASCII format. The spacecraft position values (words 5-9), the field intensity (word 10) and the GSE and GSM cartesian components (words 14-18) were computed from corresponding 15-sec values. Data for 00:00- 01:00 were used for the first hourly average of the day. Words 11-13 were computed from the hourly averaged GSE cartesian components. The number of points is the number of 15-s values (themselves averages) contributing to the hourly average. The sigma's (standard deviations) carry no memory of the sigma's in the 15-s averages. The hourly averages of this data set contain only the solar wind phase of each ~12-day IMP orbit. Every hour is represented; those for which there are no IMP solar wind data have fill values in their data words. ---------------------------------------------------- The words in each data record are: WORD FORMAT Fill Value MEANING UNITS/COMMENTS 1 I5 Year 1963, 1964, etc. 2 I4 Decimal Day January 1 = Day 1 3 I3 Hour 0, 1,...,23 4 I4 999 # of points in the IMF averages 5 F6.1 999.9 X, GSE (Re) 6 F6.1 999.9 Y, GSE (Re) 7 F6.1 999.9 Z, GSE (Re) 8 F6.1 999.9 Y, GSM (Re) 9 F6.1 999.9 Z, GSM (Re) 10 F6.1 999.9 Field Magnitude Average |B| 1/N SUM |B|, nT 11 F6.1 999.9 Magnitude of Average Field Vector sqrt(Bx^2+By^2+Bz^2) 12 F6.1 999.9 Lat.Angle of Aver. Field Vector Degrees (GSE coords) 13 F6.1 999.9 Long.Angle of Aver.Field Vector Degrees (GSE coords) 14 F6.1 999.9 Bx GSE, GSM nT 15 F6.1 999.9 By GSE nT 16 F6.1 999.9 Bz GSE nT 17 F6.1 999.9 By GSM nT 18 F6 1 999.9 Bz GSM nT 19 F6.1 999.9 sigma|B| RMS Standard Deviation in average magnitude (word 10), nT 20 F6.1 999.9 sigma B SQRT[sigma(Bx)**2 + Sigma(By)**2 + Sigma(Bz)**2], nT 21 F6.1 999.9 sigma Bx RMS Standard Deviation in GSE X-component average, nT 22 F6.1 999.9 sigma By RMS Standard Deviation in GSE Y-component average, nT 23 F6.1 999.9 sigma Bz RMS Standard Deviation in GSE Z-component average, nT -------------------------------------------------------------------------------- ----------------------------------------------------------------- Related data and directories: SPDF Data and Orbits Services NSSDC Master Catalog NSSDC Contact: Natalia Papitashvili , Please acknowledge NASA's National Space Science Data Center and Space Physics Data Facility, and the Principal Investigator Dr Adam Szabo for data usage. Authorizing NASA Official: Dr. R.E. McGuire, Head, SPDF, NASA Goddard Space Flight Center 301-286-7794, e-mail: Robert.E.McGuire@nasa.gov -----------------------------------------------------------------------