HR: 15:10h
AN: A22D-07    [PDF]
TI: Direct Eddy-correlation Measurements of DMS Fluxes and Exchange Coefficients in the Equatorial Pacific
AU: * Huebert, B J
EM: huebert@hawaii.edu
AF: University of Hawaii, Dept. of Oceanography, Honolulu, HI 96822 United States
AU: Blomquist, B W
EM: blomquis@hawaii.edu
AF: University of Hawaii, Dept. of Oceanography, Honolulu, HI 96822 United States
AU: Duan, B
EM: baozhong@hawaii.edu
AF: University of Hawaii, Dept. of Oceanography, Honolulu, HI 96822 United States
AU: Bates, T S
EM: tim.bates@noaa.gov
AF: NOAA, PMEL, 7600 Sand Point Way NE, Seattle, WA 98115-0700 United States
AU: Johnson, J E
EM: james.e.johnson@noaa.gov
AF: NOAA, PMEL, 7600 Sand Point Way NE, Seattle, WA 98115-0700 United States
AU: Fairall, C W
EM: chris.fairall@noaa.gov
AF: NOAA, ETL, 325 Broadway, Boulder, CO 80305 United States
AU: Hare, J E
EM: jeffrey.hare@colorado.edu
AF: CIRES, Colorado Univ. and NOAA ETL, Campus Box 216, Boulder, CO 80309 United States
AB: In the marine atmosphere the emission of dimethylsulfide gas (DMS) is thought to be a major factor in the production of aerosols that control cloud reflectivity. The sea/air flux of DMS has been constrained mostly by budget methods that rely on assumptions about the fate of DMS in the ocean or atmosphere. Area-averaged parameterizations of these fluxes in terms of wind speed alone cannot explain all of the variability, because a) wind speed is only one factor affecting the exchange velocity (roughness, surface films, bubble spectra, and mean-square wave slope are others), and b) the parameterizations are based on observations that cannot resolve fluxes on time scales of less than a day. We measured the flux of DMS on an hourly time scale in the Eastern Equatorial Pacific from the NOAA ship R/V Ronald H. Brown, using an atmospheric pressure ionization mass spectrometer (APIMS) with an internal isotopically-labeled standard. Both standard and ambient concentrations were measured at 20 Hz. We also measured the seawater DMS concentration with a purge and trap system, so that we could compute the DMS exchange coefficient (flux/interfacial concentration difference). We will compare our transfer coefficients with those from three commonly used parameterizations and with those reported from the GASEX data sets.
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4504 Air/sea interactions (0312)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting