HR: 0800h
AN: A21A-0020    [Abstracts]
TI: Nitrogen Oxides from Biogenic Alkyl Nitrates: A Natural Source of Tropospheric Ozone
AU: * Neu, J L
EM: jneu@uci.edu
AF: University of California, Irvine, Department of Earth System Science Croul Hall, Irvine, CA 92697, United States
AU: Lawler, M J
EM: mlawler@uci.edu
AF: University of California, Irvine, Department of Earth System Science Croul Hall, Irvine, CA 92697, United States
AU: Saltzman, E S
EM: esaltzma@uci.edu
AF: University of California, Irvine, Department of Earth System Science Croul Hall, Irvine, CA 92697, United States
AU: Prather, M J
EM: mprather@uci.edu
AF: University of California, Irvine, Department of Earth System Science Croul Hall, Irvine, CA 92697, United States
AB: Observations indicate that the tropical and southern oceans are source regions for biogenic emissions of alkyl nitrates. These compounds have lifetimes of several days to a month and are a significant source of reactive odd nitrogen (NO_x) in remote regions of the atmosphere. These biogenically produced NO_x precursors represent a natural control on atmospheric composition, including the important greenhouse gases methane (CH₄) and tropospheric ozone (O₃). We present simulations from the UCI global chemical transport model (CTM) using measurement-based fluxes of methyl and ethyl nitrate from their oceanic source regions and examine the contribution of these gases to global atmospheric composition. We also discuss the sensitivity of our results to our representation of two sub-gridscale processes: wet scavenging and photolysis in the presence of broken cloud fields. Quantification of the transport and chemistry of these compounds improves our understanding of natural tropospheric ozone production as well as hydroxyl radical (OH) chemistry in both the remote regions of the modern atmosphere and the pre-industrial atmosphere.
DE: 0322 Constituent sources and sinks
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting