The vertical axis is in nanoTesla or gamma relative to an arbitrary baseline. The baselines are approximately 0 nT (nanoTesla) for D, 22275 nT for H, and 48175 nT for Z. The three "lanes" are nearly but not exactly equal in height. The SAC software scales each lane to reach from the highest value to the lowest value for the given day. Because the mean value is removed and the height rescaled for each component for each day, the traces will not line up on printouts for different days.
The magnetic field is sensed by a three component Narod S100 ring-core magnetometer. The output voltages are sampled 2000 times per second by a Guralp 16 bit DM16-R8 digitizer. The samples are filtered and decimated by factors of 10, 10, and 5. This produces four samples per second. The four samples per second are transmitted to a PC running Guralp SCREAM data acquisition software. SCREAM produces 24 hour files for each component. The files are plotted with Lawrence Livermore National Labs Seismic Analysis Code. After plotting on a Sun SPARC 20, the magnetograms are converted to gif image files by ImageMagick software.
The digitizer time-tags the samples with signals from Global Positioning System satellites.
2000 JUN15 2000 JUN16 2000 JUN17 2000JUN18 not recorded 2000JUN19 not recorded 2000JUN20 not recorded 2000JUN21 not recorded 2000JUN22 not recorded 2000 JUN23 2000 JUN24 2000 JUN25 2000 JUN26 2000 JUN27 2000 JUN28 2000JUN29 not recorded 2000 JUN302000 JUL01 2000 JUL02 2000 JUL03 2000 JUL04 2000 JUL05 2000 JUL06 2000JUL06 9.5 hours recorded 2000 JUL07 2000 JUL08 2000 JUL09 2000 JUL10 2000 JUL11 2000JUL12 not recorded 2000 JUL13 2000JUL13 10 hours recorded 2000JUL14 not recorded 2000 JUL15 STORM 14:37:51GMT/UTC 2000JUL15 Comparison of Leonard and St. John's (Newfoundland) Z magnetograms of the 2000 JUL 15 storm 2000 JUL16 2000 JUL17 2000 JUL18 2000 JUL19 (ssc)
