HR: 1330h
AN: AE42A-0794 [PDF]
TI: Optical observations of conjugate sprites in South Africa
AU: * Marshall, R A
EM: ram80@stanford.edu
AF: Stanford University, 350 Serra Mall, Stanford, CA 94305 United States
AU: Inan, U S
EM: inan@nova.stanford.edu
AF: Stanford University, 350 Serra Mall, Stanford, CA 94305 United States
AB:
Theoretical studies have predicted optical emissions and ionospheric conductivity enhancements due to precipitation of
relativistic electron beams, created by large positive cloud-to-ground discharges in the magnetically conjugate hemisphere.
In July and August 2003, an attempt was made to detect these optical emissions, called conjugate sprites, and correlate them
to sprite observations in Europe near L ™ 1.8. In the northern region, two remote-controlled low-light CCD cameras were
installed at the Observatoire Midi-Pyren"Ýes (OMP) in France to observe sprites in southern France and northern Spain.
Additionally, VLF receivers were installed in Europe to detect causative sferics and ionospheric disturbances associated with
sprites. In the southern region, the Wide-angle Array for Sprite Photometry (WASP), an array of six photometers, was set up
to observe conjugate sprites at the South African Astronomical Observatory (SAAO) near Sutherland, South Africa, with a
field-of-view magnetically conjugate to the northern observing region. A VLF receiver was also set up at SAAO to detect
ionospheric disturbances of VLF transmitter paths caused by relativistic electron beams. The team at OMP has observed over
100 sprites. Further analysis is required to determine whether conjugate sprites have been observed. We present initial
analysis of optical data recorded at SAAO as well as charge-moment analysis of causative sferics to determine the likelihood
of the conjugate events.
UR: http://www-star.stanford.edu/~vlf/southafrica/southafrica.htm
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
DE: 3334 Middle atmosphere dynamics (0341, 0342)
SC: Atmospheric and Space Electricity [AE]
MN: 2003 Fall Meeting