Abstract
Airborne measurements of the aerosol size spectra n (r) (r is radius) were made in a vertical plane extending northeastward 18 km from San Nicolas Island, California. Thin, patchy, stratus clouds were present in a deepening convective marine layer capped by a strong temperature inversion based at ∼147 m. These data show that the aerosol spectra shape changed systematically as a function of the liquid water content w, calculated from n(r), as w increased with elevation into the stratus layer. Clouds formed when w approached 0.05 g m−3 and a mode formed in n(r) near the region 3 < r < 4 μm. The horizontal variability of w was large, particularly in the middle of the convective layer.
