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[Russian version]
M a i n p
a g e
Future seminars
P a s t seminars
Seminar council
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FUTURE SEMINARS, 2013
December, 2
Vladimir Rakov (University
of Florida, Institute of Applied Physics of the RAS)
"Compact Intracloud
Lightning Discharges"
Abstract:
Compact Intracloud Lightning Discharges
(CIDs), which were first reported by Le Vine (1980), received their name
(Smith et al. 1999) due to their relatively small (hundreds of meters)
spatial extent. They
are most intense natural producers of HF-VHF (3 - 300 MHz) radiation on
Earth,
tend to occur at high altitudes (mostly above 10 km),
appear to be associated with strong convection, however, even the strongest
convection does not always produce CIDs,
tend to produce less light than other types of lightning discharges (no hot
channel?),
produce single bipolar electric field pulses (Narrow Bipolar Pulses or NBPs)
having typical full widths of 10 to 30 μs and amplitudes of the order of
10 V/m at 100 km, which is comparable to or higher than for return strokes in
cloud-to-ground (CG) flashes.
The mechanism of electromagnetic radiation of CIDs and their parameters will
be presented and discussed.
November, 19
Leopold Lobkovsky (P.P.Shirshov
Institute of Oceanology RAS)
"Geological
evolution and present lithosphere state of Arctic: field investigations,
theoretical models and practical applications"
September, 20 |
