RESEARCH

Our research group is involved in a number of areas currently. Listed below is a sample of ongoing research.

VORTEX-(2,SE,USA)

Texas Tech has been heavily involved in the Verification of the Origin of Rotation in Tornadoes Experiment (VORTEX2 - 2009, 2010; VORTEX-SE/USA - 2016-current). During these seasons, a wealth of data was collected by a broad spectrum of radar and in situ platforms. Texas Tech, specifically, has brought two instrument platforms to the field.

• StickNet - an array of 48 deployable in situ probes capable of making measurements of all atmospheric state variables (temperature, dewpoint, pressure, wind speed/direction). These platforms have real-time telemetry and have participated in a number of recent projects, including the Propagation and Evolution of Rotation in Linear Systems (PERiLS) experiment in 2022 and 2023.
• The TTUKa Radars - two 35 GHz (Ka-band) mobile Doppler radars are available for use and have been a key part of mesocyclone-scale radar objectives in recent field efforts such as TORUS (see below) in 2019, 2022 and 2023.  These platforms recently have been upgraded to include a 1.8-m diameter reflector, permitting a half-power beamwidth of 0.33 deg.

Pictured above are (left) a StickNet probe and (right) a TTUKa radar

Current avenues of research include:

• Baroclinic zones in supercell storms and quasi-linear convective systems (QLCS); assessing the relevance to low-level vorticity evolution
• The role of internal RFD surges in modulating low-level vertical vorticity
• Tornado vortex structure, particularly within the shallow inflow boundary layer and corner flow regions
• Verifying numerically simulated thunderstorm cold pools, improvements in cloud microphysics schemes

(left) Equivalent potential temperature perturbation analysis from StickNet data and (right) an animation of internal RFD surges observed by TTUKa dual-Doppler data during VORTEX2

Since 2016, we have been involved in a Congressionally mandated project named VORTEX-SE (now VORTEX-USA), aimed at an improved understanding of conditions leading to tornado development in the southeastern United States. We have continued this effort with the PERiLS Experiment, in 2022 and 2023!

StickNet deployments during a VORTEX-SE intensive observing period

TORUS Project

In collaboration with the University of Colorado and the University of Nebraska-Lincoln, we have been part of the Targeted Observation by Radars and UAS of Supercells (TORUS) project in 2019, 2022 and 2023.

The overarching goal of this project is to use unmanned aircraft systems (UAS), mobile Doppler radars and surface in situ measurements to characterize thermodynamic and kinematic gradients along flanking boundaries of supercells that are believed to be relevant to the genesis and maintenance of tornadoes.

(left) A photograph of the University of Colorado Tempest aircraft, (right) TTUKa mobile radar (top) reflectivity and (bottom) radial velocity RHIs of a streamwise vorticity current

A numerical simulation of the streamwise vorticity current (Schueth et al. 2021)

Dryline Structure and Convection Initiation

The West Texas region outlines the climatological maximum in dryline activity. Understanding the critical role of drylines in the initiation of severe thunderstorms, we are focused on a few key areas:

• Along-dryline variability on a very fine (100 m to 5 km) scale, particularly the presence of misovortices that can modulate the vertical velocity distribution
• Vertical structure of the dryline convergence zone and associated variance within the diurnal cycle
• Roles of topographic features (e.g., Caprock Escarpment) in influencing dryline evolution and convection initiation
• The inherent predictability of convection initiation from the perspective of regional-scale numerical weather prediction; improvements from adaptive observations

Animation of (shaded) reflectivity and (contoured) vertical vorticity for a series of dryline misovortices near Levelland, TX