Airborne Measurements of Lightning Locations During Flights in Coastal Thunderstorm Conditions

Abstract

Real-time, accurate, remote detection of lightning can be important for aircraft operators, and more so for platforms with higher risk and vulnerability e.g., electric aircraft, hydrogen fuel tanks, and UAVs with less conductive composite skin. At best, aircraft can receive weather updates from ground sources every 2.5 to 5 minutes, but it is not uncommon for updates to be intermittent due to connection and service stability issues. Therefore, an aircraft-mounted lightning locator may be the most practical source of real-time lightning information for pilots. Here, we present airborne lightning measurements obtained using the commercially available Stormscope Weather Mapping System (WX-500 Series 2) collocated with measurements from the Houston Lightning Mapping Array, National Lightning Detection Network, and the GOES - Geostationary Lightning Mapper. This study estimates the WX-500 to have detection efficiencies between 12 – 33% for intracloud flashes, 57 – 75% for cloud to ground flashes, and 20 – 53% for total lightning. Bearing is unbiased with a σ of 14° and 17° for Cell and Strike mode, respectively. Increasing the integration time to from 2 to 30 s and removing clear outliers beyond |50°| improves these values to σ 4° and 8°, respectively. When measuring flashes at ~50 nmi, the WX-500 range was biased high by an average of 44 and 73 nmi for Cell and Strike mode, respectively. The WX-500 strike bounds were shown to fully and accurately capture the bounds of true lightning activity when the activity was confined to one general direction. Tests show that integration times longer than one minute do not necessarily improve its ability to identify lightning bounds.

Keywords: Lightning Detection, Dangerous Weather, Airborne Measurement, Flight Safety, Decision Aid