HR: 11:05h
AN: A42B-03    [Abstracts]
TI: Evaluation of Lightning NOx Treatment in the GMI Model and its Effect on Upper Tropospheric NOx and O3
AU: * Allen, D J
EM: allen@atmos.umd.edu
AF: University of Maryland, 3417 Computer and Space Science Building, College Park, MD 20742
AU: Pickering, K E
EM: pickerin@atmos.umd.edu
AF: University of Maryland, 3417 Computer and Space Science Building, College Park, MD 20742
AU: Duncan, B N
AF: Goddard Earth Science and Technology Center and NASA GSFC, Code 916, NASA-GSFC, Greenbelt, MD 20771
AU: Strahan, S E
AF: Goddard Earth Science and Technology Center and NASA GSFC, Code 916, NASA-GSFC, Greenbelt, MD 20771
AU: Rodriguez, J M
AF: University of Miami and NASA GSFC, Code 916, NASA-GSFC, Greenbelt, MD 20771
AB: Ideally, model simulations of tropospheric ozone specify the lightning odd nitrogen (NOx) source in a manner that is consistent in time and space with the convective transport of ozone precursors. This consistency can be achieved if the lightning NOx distribution is parameterized in terms of convective fields from the driving GCM and/or data assimilation system (DAS). The Global Modeling Initiative (GMI) off-line tropospheric chemistry model can be driven by meteorological fields from a variety of GCMs and/or DASs. Therefore, it is an ideal tool to explore the sensitivity of trace gas distributions to the driving meteorological model. In this experiment, we explore the sensitivity of NOx and ozone to the the lightning NOx distribution. The method used to parameterize flash rates in the GMI model will be discussed. Lightning NOx production in the GMI model can be specified in terms of climatological convective cloud top heights from ISCCP or in terms of six-hour averaged and normalized upward convective mass fluxes from the driving meteorological model (GEOS DAS, NCAR CCM3, or GISS GCM). Parameterized lightning distributions from simulations driven by each of these models will be compared with the ISCCP-based flash rate distribution and with lightning observations. The sensitivity of upper tropospheric ozone to the distribution of lightning NOx will be evaluated for simulations with ISCCP-based and meteorological model-based lightning distributions.
DE: 3324 Lightning
DE: 3337 Numerical modeling and data assimilation
DE: 3314 Convective processes
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting