Photographic and lightning mapping observations of a blue starter over a New Mexico thunderstorm

On 4 August 2010 a small blue starter was observed over an active thunderstorm in west-central New Mexico. The storm was of normal polarity with upper positive charge over midlevel negative charge. The event was visually observed and photographed, and mapped by the Lightning Mapping Array (LMA) at Langmuir Laboratory. The blue starter occurred during a seven-stroke negative cloud-to-ground (-CG) flash that was detected by the National Lightning Detection Network (NLDN), and data from the LMA show that it initiated between upper positive charge and inferred negative screening charge at the cloud top. Upward positive streamers of the blue starter emerged from the cloud top at 15.2 km altitude and reached a terminal altitude of similar to 17 km. The observation confirms that blue starters can be initiated by the electric field changes associated with -CG flashes, which enhance the electric field between upper positive charge and negative screening charge. It also confirms that the upward leaders and streamers of blue starters in normal-polarity storms are of positive polarity. Citation: Edens, H. E. (2011), Photographic and lightning mapping observations of a blue starter over a New Mexico thunderstorm, Geophys. Res. Lett., 38, L17804, doi: 10.1029/2011GL048543.