Cloudiness and marine boundary layer dynamics in the ASTEX Lagrangian experiments. Part II: cloudiness, drizzle, surface fluxes, and entrainment

The Analysis of the Atlantic Stratocumulus Transition Experiment (ASTEX) Lagrangians is continued, presenting measurements of sea surface temperature, surface latent and sensible heat fluxes from bulk aerodynamic formulas, cloud fraction, and drizzle rate for the two Lagrangians, mainly using data from horizontal legs flown by the Electra and C130. Substantial drizzle, averaging 1 mm day^-1 at the surface, was measured during the first Lagrangian. The surface fluxes increased rapidly as the air mass advected over rapidly increasing SST. Cloud fraction remained high throughout. During the second Lagrangian, drizzle formed in the stratocumulus layer but mainly evaporated in the deep, dry cumulus layer and the subcloud layer before reaching the surface. -from Authors