ENA Marine Clouds

Shallow marine clouds at the Eastern North Atlantic (ENA) atmospheric observatory are the foci of the third Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) scenario, LASSO-ENA. LASSO-ENA simulations are designed around investigating science questions related to cloud organization and precipitation processes.

Simulations have been produced for over 60 case dates spanning open-cell, closed-cell, and transitioning cloud regimes with shallow marine clouds. These use the System for Atmospheric Modeling (SAM) model with 100-meter grid spacing and a semi-idealized doubly periodic domain configuration. Ensembles are available that examine sensitivity to forcing data source and scale, as well as aerosol concentration. These provide information regarding sensitivity to the background meteorology and aerosol conditions for cloud formation.

A selection of case dates are further simulated with larger domains, at 102.8 kilometers, to more accurately address science questions around organized cloud structures. Highly detailed cloud treatments using spectral-bin microphysics have been used, with the bulk of the simulations having ice-phase microphysics disabled and a selection of sensitivity tests run that include ice.