TORUS Doppler Lidar and Radiosonde Wind Observation Intercomparison

The Targeted Observation by Radars and UAS (unmanned aircraft systems) of Supercells (TORUS) project is an ongoing collaborative research project funded by the National Science Foundation and NOAA. The first TORUS field season took place in May and June of 2019. Bringing more than 50 researchers from 7 institutions together in the field, TORUS deployed a wide-ranging suite of instruments in the field to observe supercell thunderstorms with the goal of improving the conceptual model of supercells and their relationship to boundaries in the context of tornadogenesis. As part of this effort NOAA-NSSL supported the deployment of a mobile Doppler lidar platform to collect observations in the near-inflow supercell environment. Over the course of the 2019 TORUS field season, the lidar was deployed on 17 days. Typically, the lidar used a scan strategy which included a single 70-degree elevation plan-position indicator (PPI) scan every 2 minutes with continuous vertical stares in between. Horizontal wind profiles can be retrieved from the PPI scans every 2 minutes roughly 30-m vertical resolution. These deployments resulted in over 20 hours of horizontal wind profile observations. In addition to the lidar scans, 36 radiosondes were released from the lidar location during TORUS 2019.

This study uses the Doppler lidar retrieved horizontal winds alongside radiosonde winds from colocated balloon releases to present a summary picture of each platform’s perspective of low-level winds in the vicinity of convective storms. Since radiosondes are commonly used for low-level environment characterization and their results well documented, this work serves the purpose of introducing the Doppler lidar platform and establishing the reliability of its observations in these environments. Additionally, this comparison allows us to explore differences in the physical representativeness of each platform. A thorough understanding of the quality and representativeness of Doppler lidar wind retrievals enables confident application of these data for future research goals including the study of rapid evolution of low-level winds in the near-inflow region of supercells.