Standardized daily high-resolution large-eddy simulations of the Arctic
boundary layer and clouds during the complete MOSAiC drift
Abstract
This study utilizes the wealth of observational data collected during
the recent MOSAiC drift experiment to constrain and evaluate 190 daily
Large-Eddy Simulations (LES) of Arctic boundary layers and clouds at
turbulence-resolving resolutions. A standardized approach is adopted to
tightly integrate field measurements into the experimental
configuration. Covering the full drift represents a step forward from
single-case LES studies, and allows for a robust assessment of model
performance against independent data under a broad range of atmospheric
conditions. A homogeneously forced Eulerian domain is simulated,
initialized with radiosonde and value-added cloud profiles. Prescribed
boundary conditions include various measured surface characteristics.
Time-constant composite forcing is applied, primarily consisting of
subsidence rates sampled from reanalysis data. The simulations run for
multiple hours, allowing turbulence and mixed-phase clouds to spin up
while still facilitating direct comparison to MOSAiC data. Key aspects
such as the vertical thermodynamic structure, cloud properties, and
surface energy fluxes are satisfactorily reproduced and maintained.
Specifically, the model captures the bimodal distribution of atmospheric
states that is typical of Arctic climate. Selected days are investigated
more closely to assess the model’s skill in maintaining the observed
boundary layer structure. The sensitivity to various aspects of the
experimental configuration and model physics is tested. The model input
and output are available to the scientific community, supplementing the
MOSAiC data archive. The close agreement with observed meteorology
justifies the use of LES data for gaining further insight into Arctic
processes and their role in Arctic climate change.