Diagnostic Model Studies Using Field Observations and Eulerian Model Output

L. I. Kleinman
Atmospheric Sciences Division
Environmental Sciences Department
Brookhaven National Laboratory
P.O. Box 5000, Building 815E
Upton, NY 11973-5000
631-344-3796
fax 631-344-2887
kleinman@bnl.gov

A diagnostic modeling study addresses questions of O3 and PM formation under conditions observed in Atmospheric Chemistry Program field campaigns. A detailed picture is obtained of the time evolution of a polluted air mass as it is advected from an emission source region eventually to merge into the background. This picture contains a description of the accumulation of O3, PM, and Indicator Species, and the relation between these quantities and emissions of precursors. The Constrained Steady State (CSS) calculations will be used to determine radical concentrations, O3 production rates, and NOx vs VOC sensitivities. Previously, these calculations were performed using observed trace gas concentrations from the G-1 as input. The spatial and temporal coverage of the G-1 will be augmented by using output concentration fields from the Pacific Northwest National Laboratory (PNNL) Eulerian model as a surrogate reality. This effort will provide the near-field to far-field coverage needed to investigate the entire time dependent process of O3 and PM production. By subjecting the field observations and the Eulerian model output to the same diagnostic procedures we will perform, a process-based evaluation of the Eulerian model will be carried out. By comparing observed Indicator Ratios and CSS calculations with Eulerian model results for perturbed emission rates, the Observation-Based Methods of inferring O3 control strategies will be evaluated. Gas-phase calculations will be extended to include gas-aerosol interactions. An important component of this extension is the use the NCAR Master Mechanism to determine production rates of multi-functional, VOC oxidation products that have low vapor pressure or high solubility.

Some further information can be found in the viewgraphs from a presentation at the Atmospheric Sciences Program Annual Meeting held in February 2001. Additional information can be found in the viewgraphs from a presentation at the Atmospheric Sciences Program Annual Meeting held in March 2002.