Abstract
The occurrence context of compact intracloud discharges (CIDs) is examined using their electric field waveforms and corresponding NLDN data. A total of 1096 CIDs transporting negative charge upward and 8 CIDs transporting positive charge upward were analyzed. The CIDs were categorized based on whether they were isolated or were followed, preceded, or both followed and preceded by other NLDN-reported lightning events. The percentages of isolated CIDs transporting negative charge upward decreased from 92% for 5 km search radius and ±10 ms time window to 31% for 10 km and ±1000 ms, this decrease being accompanied by an increase of the percentage of CIDs preceding (initiating) normal lightning events from 6.8% to 43%. GM NLDN-reported peak currents for isolated CIDs (33 kA) were similar to those initiating normal lightning events (34 kA). Some of our isolated CIDs could be viewed as precursors, because they apparently initiated normal lightning events at essentially the same location after time intervals measured in seconds. CIDs transporting positive charge upward (a) occurred at heights ranging from 16 to 19 km vs. 6 to 16 km for CIDs transporting negative charge upward and (b) had considerably higher NLDN-reported peak currents: 113 kA vs. 33 kA (GM values).
Highlights
The analyses were performed for 2 search radii
for 4 different time windows centered at the time of compact intracloud discharges (CIDs)
electric fields were sensed with a 0.8-m long whip antenna followed by a pre-amplifier
Summary
In the LDWSS, electric fields were sensed with a 0.8-m long whip antenna followed by a pre-amplifier. The pre-amplifier included an integrator and a unity-gain, low-noise amplifier. The signal from the pre-amplifier was transmitted, via a 10-m long coaxial cable, to the main unit, which was installed inside the LOG cupola and consisted of analog signal conditioning circuitry and digitizing system. The conditioning circuitry included a 500-kHz low-pass anti-aliasing filter, a 30-Hz high-pass filter, and a programmable gain amplifier (PGA). The sampling rate of the digitizing system was 1 MHz. The digitizing system had an RTC (Real Time Clock) which was synchronized with a GPS module
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
