A History of Storm Electricity Research at the National Severe Storms Laboratory (NSSL)
Abstract
Many of the early advances in observational capability and in understanding of the electrical nature of severe storms were based on research at NSSL starting in 1977. During the following decade, NSSL's innovations included adapting several observational technologies to a mobile platform, culminating in a mobile balloon launching facility. NSSL also installed multiple lightning mapping systems, including a three-dimensional VHF mapping system, an array of thunder microphones, an L-band radar, and the first LLP direction-finder network to map +CG flashes.
The following are among advances made using these facilities: Severe storms produce large flash rates, consisting mostly of intracloud flashes, and can produce +CG flashes The vertical polarity of the charge distribution in storm's producing CGs dominated by +CGs typically is inverted in at least some region Lightning flashes extend through the moderate reflectivities of storms and reflect the airflow within and extending downstream from updrafts, consistent with the advection of charge from updrafts MCS stratiform precipitation regions typically have CGs dominated by +CG flashes and have hundreds of Coulombs of charge in multiple horizontally extensive layers The vertical distribution of charge outside of strong updrafts typically is more complex than the tripole paradigm Using these advances, NSSL incorporated electrification mechanisms and two lightning parameterizations in three-dimensional numerical cloud models. With these, they demonstrated that noninductive charging of graupel and small ice particles is sufficient to electrify thunderstorms and that inductive mechanisms are not likely responsible. They also developed lightning data assimilation techniques for weather forecast models. Currently NSSL is refining their balloon-borne electric field meter and particle imager and constructing a deployable Lightning Mapping Array to participate in the multi-institutional field programs needed to address such issues as the microphysics contributing to additional electrification in storm anvils and stratiform regions, the electrical discharges and charge structures in overshooting tops and in the turbulent regions of severe storm updrafts, and the electrification and lightning of tropical cyclones.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMAE12A..08M
- Keywords:
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- 3304 Atmospheric electricity;
- ATMOSPHERIC PROCESSES;
- 3324 Lightning;
- ATMOSPHERIC PROCESSES;
- 1704 Atmospheric sciences;
- HISTORY OF GEOPHYSICS