HR: 0800h
AN: AE31A-0029 [Abstracts]
TI: Analysis of Charge Transport During Lightning Using Balloon-Born Electric Field Sensors and Lightning Mapping Array
AU: * Hager, W W
EM: hager@math.ufl.edu
AF: University of Florida, Department of Mathematics
358 Little Hall PO Box 8105, Gainesville, FL 32611-8105, United States
AU: Sonnenfeld, R G
EM: rsonnenf@nmt.edu
AF: New Mexico Institute of Mining and Technology, Department of Physics and Langmuir
Laboratory, Socorro, NM 87801, United States
AU: Aslan, B C
EM: aslan@math.ufl.edu
AF: University of Florida, Department of Mathematics
358 Little Hall PO Box 8105, Gainesville, FL 32611-8105, United States
AU: Lu, G
EM: gplu@nmt.edu
AF: New Mexico Institute of Mining and Technology, Department of Physics and Langmuir
Laboratory, Socorro, NM 87801, United States
AU: Winn, W P
EM: winn@loon.nmt.edu
AF: New Mexico Institute of Mining and Technology, Department of Physics and Langmuir
Laboratory, Socorro, NM 87801, United States
AU: Boeck, W L
EM: boeck@niagara.edu
AF: Niagara University, Computer and Information Sciences and Physics, Niagara University,
NY 14109, United States
AB:
Techniques are developed for processing the wide band measurements of
electric field obtained by a balloon-borne electric field sonde (or Esonde),
and for estimating the charge transport associated with lightning.
The techniques use Lightning Mapping Array measurements
of the VHF pulses generated during lightning recorded simultaneously
with the Esonde data.
A filtering algorithm is developed
to separate the background field associated with
instrument rotation and cloud charging processes from the
lightning-induced electric field change. The charge transport associated
with lightning is approximated by constrained monopoles and dipoles.
The constraints used to achieve a unique fit include conservation of
charge, charge separation constraints, location constraints associated
with the observed LMA pulses, and statistical constraints based on
estimated errors in instrument calibration. The location constraint
is handled using a "pulse graph," a graph whose vertices coincide with
the observed LMA pulses. The techniques are illustrated using electric
field data measured on 18 August 2004 near Langmuir Laboratory.
In our analysis we observe that current flow lags behind the
LMA detected channel formation by on the order of 0.1 s, roughly
the same time delay observed for lightning optical signals detected
by NASA's Lightning Imaging Sensor.
UR: http://www.math.ufl.edu/~hager/Lightning
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2007 Fall Meeting