HR: 13:55h
AN: A22D-02    [PDF]
TI: Climate Induced Changes in Biogenic Emissions - Global Chemical and Radiative Effects
AU: * Atherton, C S
EM: atherton2@llnl.gov
AF: Lawrence Livemore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94550 United States
AU: Bergmann, D J
EM: bergmann1@llnl.gov
AF: Lawrence Livemore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94550 United States
AU: Dignon, J E
EM: dignon1@llnl.gov
AF: Lawrence Livemore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94550 United States
AU: Grant, K E
EM: grant3@llnl.gov
AF: Lawrence Livemore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94550 United States
AU: Tannahill, J R
EM: tannahill1@llnl.gov
AF: Lawrence Livemore National Laboratory, P.O. Box 808, L-103, Livermore, CA 94550 United States
AB: A number of key biogenic emissions are temperature-sensitive. Thus, future climate and temperature changes may lead to changes in the emissions of naturally occurring species such as N2O, NOx, CH4, and isoprene. Once in the atmosphere, these gases react to form other gases and aerosols and feedback to alter the earth's radiative balance. We examine the possible influence of climate change and the accompanying change in biogenic emissions on upper tropospheric/lower stratospheric species distributions. Specifically, we use a three-dimensional, global chemistry/transport/deposition model (IMPACT). IMPACT contains over 300 prognostic tropospheric and stratospheric reactions. Reactions appropriate for the stratosphere include those for Ox, NOy, ClOy, HOy, BrOy, SOx, and CH4 and their oxidation products. The model also accounts for methane-produced water vapor in the stratosphere. Reactions appropriate for the troposphere include those for O3, OH, PAN, NO, NO2, CO, CH4, HNO3, SOx, H2SO4, isoprene, ethane, propane, C4-5 alkanes, C6-8 alkanes, ethene, propene, ketones (including acetone), formaldehyde, acetaldehyde, higher aldehydes, and their products. We simulate both a baseline scenario and a scenario in which temperature increases 1 - 4 degrees C. The prescribed temperature increase is allowed to alter the emissions of a number of biogenic species: N2O, soil NOx, lightning NOx, CH4, and isoprene. The resulting effects on key tropospheric and stratospheric species are calculated, and possible changes in radiative forcing are estimated.
DE: 0330 Geochemical cycles
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting