HR: 0830h
AN: A51E-0731    [PDF]
TI: Ozone Prediction for the 2002 Air Quality Forecasting Pilot Program Using a Hybrid (Lagrangian-Eulerian) Photochemical Model
AU: * Stein, A F
EM: astein@ceam.es
AF: Fundacion CEAM, c/Charles Darwin 14. Parque Tecnologico., Valencia, 46980 Spain
AB: The Hybrid Single-Particle Lagrangian Integrated Trajectories with a generalized non-linear Chemistry Module (HY-SPLIT CheM) model has been developed to calculate the spatial and temporal distribution of different chemical species in the lower troposphere over a regional scale. The simulation relies on a Lagrangian particle approach to compute transport, dispersion and deposition; and uses an Eulerian framework to represent chemical transformations of different air contaminants. HY-SPLIT CheM has been configured to simulate 48-hour ozone mixing ratios for the eastern United States. Air concentrations are computed based upon a 1/2x1/2-degree resolution grid and 10 vertical layers. Emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) are based upon the Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system. The forecast simulations only include pollutant sources between 25-50 N latitude and 65-100 W longitude. Transport and dispersion is computed using meteorological fields from the Mesoscale Model Version 5 (MM5) model with a horizontal resolution of 45 km, once each day, based upon the 0000 UTC forecasts (to 48 h). The Carbon Bond IV chemical mechanism is used to simulate the photochemical smog formation. Each calculation is started with all the lagrangian particles that are on the domain at the model's initialization time as computed from the previous day's simulation (yesterday's 24 h forecast). Pollutant particles may accumulate for up to 72 h before termination, although most of them are advected off the grid prior to reaching their age limit. The ability of HY-SPLIT CheM to simulate ozone mixing ratios is evaluated by comparing calculated ozone mixing ratios against measured values for a 25-day period (5-29 August 2002). HY-SPLIT CheM is the first operational implementation of the particle-in-grid approach applied to air quality forecasting. This model constitutes a feasible tool for ozone prediction due to its speed and low cost of implementation.
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting