Confronting resolved turbulence in Large-Eddy Simulations of Arctic mixed-phase clouds with aerial system data collected during the MOSAiC drift

Mixed-phase clouds play a key role in shaping the Arctic atmospheric boundary layer (ABL). Cloud-top radiative cooling drives turbulent processes within these clouds and influences their microphysical and thermodynamic behavior. In recent years, large eddy simulations (LES) have been increasingly used as a research tool for investigating the Arctic atmospheric boundary layer under different conditions. Although encouraging results have been obtained with LES in Arctic conditions, the observational data needed to critically assess its skill in resolving Arctic turbulence were hard to obtain. The recent Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provides unique and state-of-the-art in situ data on turbulence in Arctic ABLs that can effectively be used to evaluate LES. Building on this, this work aims to estimate and optimize the simulation performance of the Dutch Atmospheric Large Eddy Simulation (DALES) model on turbulence by comparison with Campaign datasets. A recently published measurement-informed standardized setup is used for DALES to simulate the Arctic boundary layer on two selected cases based on MOSAiC data. Preliminary results show it’s feasible to compare the LES energy spectrum with observation datasets. And LES simulations on two cases show some agreement with observations in turbulent variance profiles. In the energy spectrum, the inertial subrange following -5/3 can be identified in LES for both cases. Compared with observation, both cases indicate that LES can resolve large-scale eddies in the inertial subrange while smaller-scale eddies are filtered. Overall, DALES partially reproduces the turbulence in the inertial subrange for the examined case studies. Further sensitivity tests are needed in the future.