Changing Distributions of Hydrocarbons, Alkyl Halides, Alkyl Nitrates, Carbon Monoxide, and Dimethyl Sulfide during SOFeX Oliver W. Wingenter 1, Karl B. Haase 1, Peter Strutton 3,2, Gernot Friederich 3, Simone Meinardi 4, Donald R. Blake 4, F. Sherwood Rowland 4 1 New Mexico Institute of Mining and Technology, Department of Chemistry 2 State University of New York, Stony Brook, Marine Sciences Research Center 3 Monterey Bay Aquarium Research Institute 4 University of California, Irvine, Department of Chemistry nmt.edu
SOFeX 2002 Observations made on the R/V Revelle Surface Water during the return to the Northern Patch
in patchout of patch%R compoundavestdeomavestdeomchangeO2O2 CO 2 Fluor O 2 (mL/L) CO 2 (ppm) in patch O 2 > 6.87 mL/L CO 2 < 325 ppm fluor > 10.6 volts n=11 out of patch O 2 > 6.73 mL/L CO 2 < 346 ppm fluor > 3.75 volts n=9 12 samples taken on the gradient
Trace Gases Quantified (~50 different species) Methane and nonmethane-hydrocarbons (over 15 quantified) Isoprene, ethene, propene, butenes Ethane, propane, n-butane, n-pentane, n-hexane, i-butane, i-pentane Benzene and Ethyne Alkyl Halides (over 20 quantified) methyl bromide, methyl iodide, methyl chloride ~20 other halocarbons quantified such as CFCs, HCFCs, HFCs Alkyl Nitrates MeONO 2, EtONO 2, n-PrONO 2, i-PrONO2, 2-BuONO 2 Carbon Monoxide DMS, OCS, and CS 2 Carbon Dioxide Oxygen
UCI analytical system MS
SOFeX 2002 Observations made on the R/V Revelle Surface Water during the return to the Northern Patch
Compound in patch out of patch% R pptavestdeomSA %avestdeomSA %changeO2O2 CO 2 Fluor Isoprene Ethene Propene Butene i-Butene t-2-Butene c-2-Butene CO (ppb) CH 4 (ppm) Gases effecting the oxidative capacity of the atmospheric MBL by consuming hydroxyl, the primary atmospheric oxidant. These gases also contribute to organic aerosol.
SOFeX 2002 Observations made on the R/V Revelle Surface Water during the return to the Northern Patch
compound in patch out of patch% R pptavestdeomSA %avestdeomSA %changeO2O2 CO 2 Fluor Ethane Propane n-Butane n-Pentane n-Hexane i-Butane i-Pentane Ethyne Benzene
SOFeX 2002 Observations made on the R/V Revelle Surface Water during the return to the Northern Patch
in patch out of patch% R compoundaveStdeomSA %avestdeomSA %changeO2O2 CO 2 Fluor CH 3 Br CH 3 I CH 3 Cl CH 2 Br CHBrCl CH 2 BrCl CHBr CHCl CH 2 Cl C 2 HCl C 2 Cl C 2 H 5 Cl ,2-C 2 H 4 Cl
SOFeX 2002 Observations made on the R/V Revelle Surface Water during the return to the Northern Patch
in patchout of patch% R compoundavestdeomSA %avestdeomSA %changeO2O2 CO 2 Fluor MeONO EtONO n-PrONO i-PrONO BuONO Source of NO y to the Atmosphere
in patch out of patch% R compoundavestdeomSA %avestdeomSA %changeO2O2 FluorCO 2 DMS OCS CS
Conclusions Iron fertilization in the North Patch resulted in large increases in DMS and isoprene. Changes in C 2 -C 4 alkenes were insignificant but may be important as the biomass degrades. CO decreased nearly 50 percent. CH 4 was unchanged. Straight-chain alkanes increased, while branched alkanes increased slightly or were consumed. Changes in the oxidative capacity of the atmospheric boundary layer can result in changes in the atmospheric lifetime of DMS. A longer lifetime allows for more transport of this aerosol precursor to the buffer layer. Because the BuL is not directly coupled to the ocean surface, the lifetime of these nascent particles would be considerably longer. CH 3 I was consumed, CH 3 Br increased while CH 3 Cl was unchanged. Anthropogenic halocarbons such as CFCs were not effected. Acknowledgments Ken Johnson and Kevin Sullivan Dick Barber and Sue Brown and the rest of the Revelle Science Team Crew of the R/V Revelle