Acquisition of a Three Dimensional Lightning Channel Mapping Network for the Houston, Texas Area

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This grant supports the acquisition, installation, and initial operation of a 12-station Lightning Detection and Ranging (LDAR) network to map the paths of lightning flashes in the Houston area. Each station receives the VHF signal emitted by lightning with high-resolution GPS timing. The paths of the lightning strokes are then determined by triangulation. The LDAR is a commercial version of the lightning mapping array (LMA) originally developed by researchers at New Mexico Institute of Mining and Technology under NSF support. An LDAR network in Houston will lay the groundwork for an extensive study of what appears to be an anomalously high amount of lightning activity in that area. Data on cloud-to-ground lightning flashes from the National Lightning Detection Network for the past decade indicate a considerably higher flash density over Houston than over the nearby surrounding area. Speculation is that it may be related to the high level of atmospheric pollution over Houston, which could affect cloud microphysics and the charging mechanism, or that it may only be associated with the urban heat island. The LDAR network, in connection with existing and planned radar, airborne, and surface observations, will document the lightning in great detail and provide the information needed to test various hypotheses that explain the anomaly. The work not only contributes to the physics of lightning, but also advances the understanding of weather hazards.