TY - JOUR
T1 - Simultaneous radio and satellite optical measurements of high-altitude sprite current and lightning continuing current
AU - Cummer, Steven A.
AU - Frey, Harald U.
AU - Mende, Stephen B.
AU - Hsu, Rue Ron
AU - Su, Han Tzong
AU - Chen, Alfred B.
AU - Fukunishi, Hiroshi
AU - Takahashi, Yukihiro
PY - 2006/10/1
Y1 - 2006/10/1
N2 - We report coordinated measurements of lightning and resulting sprites using ground-level magnetic field sensors (<0.1 Hz to 30 kHz bandwidth) and the ISUAL instrument on the FORMOSAT-2 satellite. These measurements demonstrate two distinct elements of the connection between the radio and optical emissions. First, the quasi-static magnetic field signature is tightly correlated with the low-altitude optical emissions from the lightning flash, indicating that this radio signature is produced by continuing lightning current. Second, in two events with strong postretum stroke extremely low frequency (ELF) magnetic pulses, the optical emissions demonstrate that there are no observable intensifications of low-altitude optical emissions associated with those pulses. If they were produced by a lightning process, such as an M-component, the connection between optical emissions and current seen in the return stroke and the continuing current suggests they should be visible. However, as has been observed previously, the bright, high-altitude optical emissions associated with the sprite are simultaneous with the ELF pulse. This is strong evidence that these ELF pulses originate in high-altitude electric current in the sprite itself and are not produced by a low-altitude lightning process.
AB - We report coordinated measurements of lightning and resulting sprites using ground-level magnetic field sensors (<0.1 Hz to 30 kHz bandwidth) and the ISUAL instrument on the FORMOSAT-2 satellite. These measurements demonstrate two distinct elements of the connection between the radio and optical emissions. First, the quasi-static magnetic field signature is tightly correlated with the low-altitude optical emissions from the lightning flash, indicating that this radio signature is produced by continuing lightning current. Second, in two events with strong postretum stroke extremely low frequency (ELF) magnetic pulses, the optical emissions demonstrate that there are no observable intensifications of low-altitude optical emissions associated with those pulses. If they were produced by a lightning process, such as an M-component, the connection between optical emissions and current seen in the return stroke and the continuing current suggests they should be visible. However, as has been observed previously, the bright, high-altitude optical emissions associated with the sprite are simultaneous with the ELF pulse. This is strong evidence that these ELF pulses originate in high-altitude electric current in the sprite itself and are not produced by a low-altitude lightning process.
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U2 - 10.1029/2006JA011809
DO - 10.1029/2006JA011809
M3 - Article
AN - SCOPUS:33947507530
SN - 2169-9380
VL - 111
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
IS - 10
M1 - A10315
ER -