This directory contains files with Open Closed field line Boundaries obtained from different instruments
YR, SOY, NB, PHICENT, RCENT, R, A, R_ERR, R_MERIT
YR : Year SOY : Seconds of year (be careful in leap years) NB : Number of MLT sectors that a boundary existed for that fit PHICENT : Angle from midnight of the line from the AACGM pole to the ‘fitted pole’ (effectively MLT*15) RCENT : AACGM Co-latitude of the location of the ‘fitted pole’ R : radius of the circle (co-latitude) remembering that the circle centre is the ‘fitted pole’ in degrees A : Psuedo area of the circle (as in AACGM, not geographic) R_ERR : Root-mean squared error in the radius in degrees R_MERIT : Radial distance from the most typical pole location in degrees
There are certain ranges for NB, RCENT, and R that you shouldn’t use that can be found (and explained) in Chisham (2017), doi:10.1002/2016JA023235. These ranges are the defaults in OCBoundary.get_next_good_ocb_ind. When using these boundaries, remember to cite Chisham (2017). From ocbpy version 0.3.0 onward, the SI12, SI13, and WIC files contain uncorrected auroral boundary fits, while the IMAGE file contains DMSP corrected average boundaries for the OCB and EAB.
DATE, TIME, RADIUS, X, Y, J_MAG
DATE : 4-digit year, 2-digit month, and 2-digit day of month (YYYYMMDD) TIME : 2-digit hours of day and 2-digit minutes of hour, separated by a colon RADIUS : Radius of the R1/R2 boundary circle in degrees X : Location of the R1/R2 boundary circle centre in degrees along the dawn/dusk axis Y : Location of the R1/R2 boundary circle centre in degrees along the noon/midnight axis J_MAG : Largest positive-to-negative changed in the summed currents (micro amps per meter)
There are certain ranges for J_MAG that shouldn't be trusted. This limitation is explained in Milan et al. (2015), doi:10.1002/2015JA021680. This range is the default in OCBoundary.get_next_good_ocb_ind. When using these boundaries, remember to cite Milan et al. (2015). If the OCB correction was applied, also remember to cite Burrell at al. (2019).
amp_north_radii.txt : Active Magnetosphere and Planetary Electrodynamics Response Experiment [Waters, et al. (2001), Geophys. Res. Lett., 28, 2165-2168] amp_south_radii.txt : Active Magnetosphere and Planetary Electrodynamics Response Experiment [Waters, et al. (2001), Geophys. Res. Lett., 28, 2165-2168] si12_north_circle.xxx : Spectrographic Imager SI12 [Mende, et al. (2000), Space Sci. Rev., 91, 287–318] si13_north_circle.xxx : Spectrographic Imager SI13 [Mende, et al. (2000), Space Sci. Rev., 91, 287–318] wic_north_circle.xxx : Wideband Imaging Camera (WIC) [Mende, et al. (2000b), Space Sci. Rev., 91, 271–285] image_north_circle.xxx : Combined data from all IMAGE instruments