TORUS in the Clear Air: Pre-Convection Observations from a Profile and Transect Perspective

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. While not directly connected to the main goals of the TORUS mission, multiple opportunities arose to collect observations of the pre-convection boundary layer with a robust armada of meteorological observation platforms including lidar, radars, UAS, manned aircraft, radiosondes, and mobile ground observations.

This presentation will offer an overview of two such deployments targeting drylines in the pre-convection boundary layer: 11 June 2019 and 14 June 2019. In each case, a Doppler lidar was deployed near the middle of the ground armada near the dryline. The lidar collected observations of vertical velocity with high spatial and temporal resolution and was colocated with a vertical profiling UAS for thermodynamic observations. Additional UAS and mobile ground observation teams performed east-west transects orthogonal to the dryline boundary, providing kinematic and thermodynamic observations of the moist air mass, boundary zone, and dry air mass as the boundary moved. The NOAA P3 aircraft also flew transect legs directly over the Doppler lidar position collecting flight level data and downward pointing thermodynamic observations from an onboard compact Raman lidar. In addition to the aforementioned observations, radiosondes were released intermittently on both sides of the dryline. These observations will be summarized to identify potential research questions for further analysis. In addition to motivating future research directions, these data also allow us to see the potential utility of collecting clear-air observations with platforms more typically used for severe weather applications.