HR: 0800h
AN: AE41A-0150    [Abstracts]
TI: Using the Los Alamos Sferic Array to Look for Positive Leaders
AU: * Stock, M
EM: mstock@lanl.gov
AF: Los Alamos National Laboratory, Space and Remote Sensing Sciences ISR-2, MS D436, Los Alaoms, NM 87545 United States
AU: Shao, X
EM: xshao@lanl.gov
AF: Los Alamos National Laboratory, Space and Remote Sensing Sciences ISR-2, MS D436, Los Alaoms, NM 87545 United States
AU: Stanley, M
EM: stanleym@lanl.gov
AF: Los Alamos National Laboratory, Space and Remote Sensing Sciences ISR-2, MS D436, Los Alaoms, NM 87545 United States
AU: Harlin, J
EM: harlin@lanl.gov
AF: Los Alamos National Laboratory, Space and Remote Sensing Sciences ISR-2, MS D436, Los Alaoms, NM 87545 United States
AB: In the spring of 2004, Los Alamos Nation Laboratory deployed a newly updated array of electric field change stations, the Los Alamos Sferic Array (LASA), in Florida. New triggering techniques and increased sensitivity allows LASA to capture very low amplitude signals. This increased sensitivity may allow LASA to detect positive leaders in nearby lightning events. Negitive leaders are known to be impulsive and bright in the VHF. Positive leaders are more continuous in nature and therefore should apear as a slow rise in the signal. Identifying positive leaders is difficult; they produce an electric field deflection at ground in the same direction as brighter negitive leaders, and their signal falls off rapidly with distance because of its large DC component. Because positive leaders are continuous, there should be a small positive deflection before the first negitive leader pulse. To detect positive leaders, we are looking at Intercloud (IC) and Narrow Bipolar (NB) waveforms located within 15 Km of a station that have no activity located within 30 Km of the same station for the 2 seconds preceding the flash. The first significant deflection of a record is located, and the preceding portion of the record is compared to similar portions of multiple other records.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
DE: 3360 Remote sensing
SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005