Identification and Tracking of Locust Swarms by Indian Doppler Weather Radar

Abstract

The desert Locust swarms are a severe threat to the agriculture sector and have invaded northern India over large areas. Locust swarms are expected to give echoes comparable with those given by heavy precipitation since the Locusts contain more than 50% of their body weight as water. During June and July of 2020, the northern part of India experienced a Locust invasion and they were observed by two Doppler weather radars (DWRs) viz. Delhi and Lucknow. A strong echo in radar reflectivity is observed in both the radars throughout the Locust flight. The mean vertical profile shows echo strength of more than 40 dBZ for all Locust clusters and the maximum vertical extent up to a height of 1.5 km. The tracks were also compared with the hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) and showed the possible tracks of Locust reaching Delhi and Lucknow on the day of observation. The five-day backward trajectories on June 27th and July 12th, 2020 indicate air parcel movements from Rajasthan toward Delhi and Lucknow, where the invasion of Locust was observed.