Research Highlights

We systematically investigated the influence of water vapor fluctuations on turbulence statistics in the convective atmospheric boundary-layer using a series of numerical simulations. Although water vapor is typically assumed to play a passive role in turbulence dynamics, we find that it plays an active role, where it contributes to buoyancy independently of temperature and influences the nature of turbulent transport under humid conditions.

New aerosol particle formations within the marine boundary layer (MBL) have been difficult to pin down, limiting how well earth system models represent this aerosol source. Using measurements from the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Aerial Facility's G-1 aircraft during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign, researchers applied a continuous wavelet transformation technique to derive vertical turbulent fluxes of freshly nucleated 3-10nm particles. This approach sidesteps the stationarity assumptions that limit traditional eddy covariance methods on a fast-moving aircraft platform, and it uses flux direction—upward versus downward—to infer whether a nucleation source lies above or below the aircraft.

Marine shallow cumulus clouds cool the Earth by reflecting solar radiation back to space and are challenging to accurately represent in earth system models. These clouds are intimately coupled with turbulence in the boundary layer. Here, vertical air motion and its co-variability with cumulus cloudiness are characterized using data from the Atmospheric Radiation Measurement (ARM) Eastern North Atlantic (ENA) observatory.