Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL) Campaign: High-Resolution in situ Observations above the Nocturnal Boundary Layer

Abstract

Abstract. The Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL) project was conceived to improve our understanding of the dynamics of sheet and layer (S&L) structures in the lower troposphere under strongly stable conditions. The approach employed a synergistic combination of targeted multi-point observations using small unmanned aircraft systems (sUAS) guiding direct numerical simulation (DNS) modeling to characterize the dynamics driving the S&L structures and associated flow features. The IDEAL research program consisted of two phases. The first was an observational field campaign to systematically probe stable lower atmosphere conditions using multiple DataHawk-2 (DH2) sUAS. Coordinated, simultaneous multi-DH2 flights were guided by concurrent Integrated Sounding System (ISS) wind profiler radar and radiosonde soundings performed by NCAR Earth Observing Laboratory (EOL) participants. Additional sUAS flight guidance was obtained from real-time sUAS measurements. Following the field campaign, the second phase focused on high-resolution DNS modeling efforts guided by in-situ observations made during the first phase. This overview focuses on the details of the observational phase that took place from 24 October to 15 November 2017 at Dugway Proving Ground (DPG), Utah. A total of 72 DH2 flights coordinated with 93 balloon-borne radiosondes were deployed in support of the IDEAL field campaign. Our discussion addresses the average atmospheric conditions, the observation strategy, and the objectives of the field campaign. Also presented are representative flight sorties and sUAS environmental and turbulence measurements.

Modeling Kelvin Helmholtz Instability Tube and Knot Dynamics and Their Impact on Mixing in the Lower Thermosphere

“…(2017), Doddi et al. (2021), Barat (1982), Sato and Woodman (1982), Lehmacher et al. (2011), and R. L. Mesquita et al.…”

“…Sharp wind and temperature gradients such as those underlying the Mesquita event exist throughout the atmosphere at scales below the resolution limit of GCMs, and the resulting Ri-critical shear layers produce local instabilities everywhere they occur. Such events arise in multi-scale environments exhibiting what are described as "sheet and layer" structures, which occur throughout the atmosphere into the MLT and which modeling reveals to be prolific sources of local KHI , see for example, Kantha et al (2017), Doddi et al (2021), Barat (1982), Sato and Woodman (1982), Lehmacher et al (2011), and R. L. Mesquita et al (2020). Though ubiquitous, GCM resolution cannot capture these dynamics , and their mixing contributions remain unaddressed.…”