Scientific Discovery with Bats on Radar

Central Texas is the warm season home for the largest bat colony in the world, Bracken Cave, with an estimated 15–20 million bats. The daily emergence from, and return of the bats to, the cave is detected by the KEWX WSR-88D radar. Other bat colonies (e.g., Congress Street Bridge in Austin, TX) are also detected. Dual polarization of the WSR-88D includes the Hydrometeor Classification Algorithm (HCA) product, which usually classifies the bats as a biological target, but sometimes classifies them as big drops (large water droplets), possibly due to the bats large size, fast movement speed, and spatial coherence as a large group. Bats and other biological entities (birds and insects) are detected by WSR-88Ds across the United States. A centralized repository has been designed to catalog, display, and teach about biological scatterers detected by radar, including how, when, and why they appear. Eventually, the site will expand to include chaff, three-body scatter spikes, velocity detected along highways, and other non-precipitation events. An accompanying Twitter account will provide real-time monitoring and information to show the habits and migration patterns of biological scatters detected by radar.