fitsYYYYMM.dat File Format Description
B. J. Anderson, 3 March 2003
Filename: fitsYYYYMM where YYYY is the year and MM is the month.
Format: Tab delimited columnar ASCII
Time Span: One month beginning at 0800 UT on the first day of the month or the first day of the
month for which data are available and ending at 0800 UT on the first day of the next month or the
last time for which data are available within that time span.
Time Resolution: Values are provided every 15 minutes using a time window of 45 minutes centered at
the time given in the second field.
First line – comma delimited variable list:
yy,xday_all,rz_fit_n_all,r0_fit_n_all,r1_fit_n_all,xc0_fit_n_all,yc0_fit_n_all,nbndry_n_all,
rz_fit_s_all,r0_fit_s_all,r1_fit_s_all,xc0_fit_s_all,yc0_fit_s_all,nbndry_s_all
Contents List:*
Col. Variable name Format Description
1 yy i4 Four digit year (i4)
2 xday_all f8.4 decimal day of year (0000 UT 1 January = 1.0000). This is the center time over which the statistics are computed.
3 rz_fit_n_all f5.1 Northern magnetic latitude of circle fit to region 1, 2 sense perturbations.
4 r0_fit_n_all f5.1 Northern poleward latitude of region 1, 2 sense perturbations. 20% of the values are poleward of this latitude.
5 r1_fit_n_all f5.1 Northern poleward latitude of region 1, 2 sense perturbations. 20% of the values are equatorward of this latitude.
6 xc0_fit_n_all f5.1 X-coordinate of Northern hemisphere center of region 1,2 circle fit: in degrees, +X sunward.
7 yc0_fit_n_all f5.1 Y-coordinate of Northern hemisphere center of region 1,2 circle fit: in degrees, +Y duskward.
8 nbndry_n_all i5 Number of 2 degree latitude bins in the North for which at least one sample is above the statistical noise threshold.
8 rz_fit_s_all f5.1 Southern magnetic latitude of circle fit to region 1, 2 sense perturbations.
9 r0_fit_s_all f5.1 Southern poleward latitude of region 1, 2 sense perturbations. 20% of the values are poleward of this latitude.
10 r1_fit_s_all f5.1 Southern poleward latitude of region 1, 2 sense perturbations. 20% of the values are equatorward of this latitude.
11 xc0_fit_s_all f5.1 X-coordinate of Southern hemisphere center of region 1,2 circle fit: in degrees, +X sunward.
12 yc0_fit_s_all f5.1 Y-coordinate of Southern hemisphere center of region 1,2 circle fit: in degrees, +Y duskward.
13 nbndry_s_all i5 Number of 2 degree latitude bins in the South for which at least one sample is above the statistical noise threshold.
* See Ref 1 for a discussion of how these averages are derived.
Remarks: Entries for which the average cannot be computed are flagged by the mnemonic “NaN” for
Not a Number. For these cases entries for format is three characters in lieu of the floating point
format given in the Contents List.
References
1. Anderson, B. J., K. Takahashi, T. Kamei, C. L. Waters, and B. A. Toth, Birkeland current system
key parameters derived from Iridium observations: Method and initial validation results,
J. Geophys. Res., 107, A6, SMP 11-1 - 11-13, 10.1029/2001JA000080, 19 June 2002.
