The Northern Atlantic Regional Aerosol Characteristic Experiment (ACE-2) was conducted in the western Atlantic Ocean near Canary Islands, Spain in the summer of 1997. During this experiment, extensive measurements of aerosol and its radiative properties, cloud microphysics, turbulence, and the atmospheric radiative properties were made by a small research aircraft, the Pelican, operated by the Center for Interdisciplinary Remotely-Piloted Aircraft Study (CIRPAS) at the Naval Postgraduate School (NPS) and by the C-130 operated by the United Kingdom Meteorological Office. We have analyzed observations from one flight of each platform made during the same day in close location, both were made in stratocumulus-topped marine boundary layers. The analysis emphasized the interaction between turbulence, aerosol, and cloud microphysics. Entrainment mixing at the boundary layer top estimated from the flux method will be presented together with the thermodynamic characteristics of the cloudy boundary layer. The effects of entrainment on droplet size spectrum will be discussed. The characteristics of aerosol and cloud droplets in the updrafts near the cloud base are also studied using a conditional sampling technique