Turbulent Diffusion of Ozone and DMS in the Stratocumulus Topped Marine Boundary Layer

Ian Faloona

NCAR Advanced Study Program

Fast measurements of ozone and dimethylsulfide (DMS) from flights onboard the NCAR C-130 over the northeastern subtropical Pacific during DYCOMS-II (the second Dynamics and Chemistry of Marine Stratocumulus experiment) are used as the basis for an empirical study of turbulent scalar diffusion in the stratocumulus topped boundary layer (STBL).  In general, DMS is continually emitted from the ocean surface whereas ozone is entrained from the free troposphere above and very slowly deposited at the surface; thus, the tracers provide complementary views of turbulent mixing in the STBL.  Aside from independent measures of boundary layer entrainment rates, based on the ratios of their fluxes to the concentration difference across the top of the inversion, these data are used to investigate the spatial scales of the entrainment process, the nature of top-down/bottom-up diffusion, ozone deposition to the ocean surface, and the aqueous reaction of the two species within cloud droplets