HR: 15:25h
AN: A22D-08    [PDF]
TI: Direct and Indirect Measurements of DMS, Ozone, and CO Fluxes Over the Eastern Pacific Ocean
AU: * Faloona, I
EM: icfaloona@ucdavis.edu
AF: University of California @ Davis, LAWR One Shields Ave., Davis, CA 95616 United States
AU: Thornton, D
EM: thorntdc@drexel.edu
AF: Drexel University, Chemistry Department, Philadelphia, PA 19104 United States
AU: Blomquist, B
EM: blomquis@hawaii.edu
AF: Drexel University, Chemistry Department, Philadelphia, PA 19104 United States
AU: Bandy, A
EM: bandyar@drexel.edu
AF: Drexel University, Chemistry Department, Philadelphia, PA 19104 United States
AU: Lenschow, D
EM: lenschow@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Campos, T
EM: campos@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301 United States
AU: Hall, S
EM: halls@ucar.edu
AF: National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80301 United States
AB: The second Dynamics and Chemistry of Marine Stratocumulus experiment (DYCOMS-II) was an integrated investigation of the stratocumulus topped boundary layer regime off the coast of Baja California using the NCAR C-130. While the suite of chemical measurements was relatively scant, the application of a novel, fast technique for measuring dimethyl sulfide (DMS) was employed to great advantage in constraining the dynamic exchange between the strongly capped marine boundary layer (MBL) and the free troposphere above. This exchange parameter, the entrainment velocity, in concert with the surface flux, plays a principal role in controlling the abundance and diurnal behavior of DMS, and most other trace gases, in the MBL worldwide. By measuring the fluxes of DMS and ozone with direct eddy-correlation methods the entrainment rates were determined with unprecedented accuracy, thereby allowing an inference to be made of the oceanic carbon monoxide emissions. The observed fluxes of DMS and ozone are found to be in line with previous estimates and measurements, but the carbon monoxide fluxes are substantially larger than others reported in the literature. Furthermore, very strong horizontal gradients of DMS were observed on almost every flight and indicate patchy emissions upwind of the target area, the orientation of which is not easily explicable from patterns of oceanic primary production.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere--composition and chemistry
DE: 0400 Biogeosciences
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting