Initial Results From the Huntsville, Alabama Field Change Array
Abstract
Previous studies using arrays of instruments measuring electric fields at the ground near thunderstorms generally focused on determining the electrostatic change caused by a lightning stroke. This data is then used to find the charge deposited in a cloud by a lightning stroke (e.g., Krehbiel, 1979, Koshak, 2007). These arrays had a characteristic bandwidths from DC to 700 Hz or less. This research introduces a new network of field change meter, the Huntsville, Alabama Field Change Array (HAFCA). HAFCA is comprised an array electric field change meters, covering roughly the same area as the North Alabama Lightning Mapping Array. Each instrument has a time constant of 100 ms and samples the electric field at 1 MHz. We present the the initial findings from HAFCA, using time-of-arrival to find the spacetime locations of lightning events, including the preliminary breakdown wavetrain and the return stroke. In addition, we introduce a new method of determining the amount of charge deposited in the cloud due to the electrostatic field change caused by a lightning stroke. This new method uses the spacetime location, as determined by time-of-arrival, to constrain the location of the charge, while the measured electrostatic changes are used to determine the magnitude of charge.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMAE32A..04B
- Keywords:
-
- 3304 ATMOSPHERIC PROCESSES / Atmospheric electricity;
- 3324 ATMOSPHERIC PROCESSES / Lightning