HR: 1340h
AN: AE23A-0844    [Abstracts]
TI: Leader Velocities of Normal and Inverted Intracloud Lightning Flashes as Observed by the Lightning Mapping Array
AU: * Thomas, R J
EM: thomas@nmt.edu
AF: Langmuir Laboratory for Atmospheric Research, New Mexico Institute of Mining and Technology, Socorro, NM 87801 United States
AU: Hamlin, T
EM: thamlin@nmt.edu
AF: Langmuir Laboratory for Atmospheric Research, New Mexico Institute of Mining and Technology, Socorro, NM 87801 United States
AU: Krehbiel, P
EM: krehbiel@ibis.nmt.edu
AF: Langmuir Laboratory for Atmospheric Research, New Mexico Institute of Mining and Technology, Socorro, NM 87801 United States
AU: Rison, W
EM: rison@ee.nmt.edu
AF: Langmuir Laboratory for Atmospheric Research, New Mexico Institute of Mining and Technology, Socorro, NM 87801 United States
AB: The New Mexico Tech lightning mapping array, LMA, has been operated during six lightning seasons. We have performed a detailed analysis of the velocities of lightning channels. The average velocity of the negative leaders have been deduced for many flashes. Normal intracloud flashes begin upward from between 6 and 10 km with velocities of about $1.5 \times 10^5$ m/s (0.5 to $3 \times 10^5$). The negative leader in inverted intracloud flashes are slower and begin downward from 9 to 12 km at about half the speed. In these flashes we isolated the branches of interest and used a cubic spline to fit each branch in X, Y, and Z versus time. As a result of the fits, we have characterized the evolution of the velocity of individual branches and the overall flash. Typical branch velocities range between $4 \times 10^4$ and $3 \times 10^5$ m/s.
UR: http://lightning.nmt.edu
DE: 3324 Lightning
DE: 3304 Atmospheric electricity
SC: Atmospheric and Space Electricity [AE]
MN: 2004 AGU Fall Meeting