Gravity waves in the atmosphere occur when a parcel of air is lifted, usually by terrain or updrafts in thunderstorms, and then gravity serves as a force to try to restore the parcel to an equilibrium state. The waves occur as the parcel overshoots its equilibrium point, rising or sinking because of its own momentum. Gravity waves play a large role in the atmosphere due to their ability to affect circulation patterns. This award is for the study of thunderstorm-induced gravity waves in the lower to middle atmosphere, using a research aircraft and remote sensing instruments. The observations will be combined with state-of-the-art numerical models to improve understanding of gravity waves and provide guidance for improving their representation in weather and climate models. The project will provide training opportunities for a number of students and early career researchers and public outreach will be conducted during a facility day and K-12 school visits.

The collaborative research team will conduct a field campaign and associated modeling effort to increase understanding of convective gravity wave (CGW) dynamics and their role in atmospheric circulation, structure, and variability from Earth's surface to the stratopause and above. Gravity waves that are generated by deep convection have not previously been quantified by full-column measurements. The CGWaveS field campaign will be conducted in the central US in June 2022 using the NSF/NCAR G-V research aircraft. The G-V will make in situ measurements using tracers of vertical transport and mixing and remote sensing measurements of radial winds from 15-25km using a Na resonance lidar and temperature and perturbations from 25-60km via a Rayleigh lidar. OH airglow measurements at 85km will provide additional data about the atmospheric structure. Multiple numerical models will be used, including the WRF in idealized and real-case configurations, the GATS Complex Geometry Compressible Atmosphere Model (CGCAM) and ERAU Model for Acoustic-Gravity wave Interactions and Coupling (MAGIC) for CGW responses extending throughout the stratosphere, and the GATS spectral DNS models that can resolve instabilities and turbulence. The measurement campaign and analysis and modeling efforts would focus on four main science goals: 1) Measure and quantify CGW generation, propagation, and variability throughout the troposphere and stratosphere, 2) Identify and quantify the convective source dynamics that dictate CGW character and orientations for a variety of source conditions, 3) Quantify CGW refraction in variable winds, breaking and instability dynamics, mean-flow interactions, and their effects in the stratosphere for a range of environments, and 4) Advance the parameterizations of both CGW generation by WSR-88D measurements and the resulting CGW nonlinear dynamics and influences in the troposphere and stratosphere.

The CGWaveS campaign is scheduled for June-July 2023.