CPP-15. A Study of Intermittent Turbulence in Stable Arctic Boundary Layers

Atmospheric boundary layers in polar environments are often characterized by strongly stable atmospheric conditions. However, current weather and climate models have difficultly accurately simulating such conditions. One potential source of this difficulty is the existence of intermittent turbulence within stable boundary layers, which has been observed by in-situ measurements and large eddy simulations. Here we present a case study evaluation of coherent structures in a stable boundary layer observed during a series of flights with an uncrewed aircraft system (UAS; DataHawk2) on 19 October 2016 at Oliktok Point, Alaska as part of the ERASMUS (Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems) field campaign. During a set of five flights over a nine-hour period 57 profiles of the lower atmosphere (surface – 200 m AGL) were collected. Intermittent turbulence was examined using a variety of metrics, including Richardson Number, TKE dissipation, and temperature structure function parameter. Here we characterize the size and propagation velocity of the turbulent layers within the stable boundary layer, identify the forces (e.g., shear, buoyancy) which influenced their dynamics, and assess the potential of such datasets for developing sub-grid parameterizations of small-scale turbulence embedded within stable boundary layers.