AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Nitrogen Oxide Emissions Perturbation and its Effects on the WRF-Chem Forecast
MEGAN CHRISTIANSEN, Maryam Abdioskouei, Negin Sobhani, Charles Stanier, Gregory Carmichael, Can Dong, University of Iowa
Abstract Number: 468 Working Group: Regional and Global Air Quality and Climate Modeling
Abstract A collaborative field campaign (Lake Michigan Ozone Study 2017, LMOS 2017) occurred during May and June 2017 to address the high ozone episodes in coastal communities surrounding Lake Michigan. Episodic ozone concentrations exceed EPA/Clean Air Act National Ambient Air Quality Standards. Sampling of numerous chemical and meteorological parameters during LMOS 2017 permits in depth testing of chemical transport model (CTM) skill for meteorology, ozone, ozone precursors, speciated PM2.5, and ozone sensitivity indicator species and ratios such as HNO3 and H2O2. Sampling platforms included one research vessel on Lake Michigan, two aircraft, two major ground sites, one mobile van, and supplemental ground sites. A daily forecast of meteorology and air quality was used to direct mobile platforms. The computer transport model, WRF-Chem, was used as a forecast tool to evaluate the gas phase and aerosol mechanisms and spatial resolution of chemically reactive area of interest during flight planning meetings. The key challenge of the forecast was to simulate the lake breeze effect. Two separate full chemistry 48-hour forecasts were initialized every evening of the campaign. The first was a base simulation with NEI-2011(v2) emissions. The second was a NOx sensitivity simulation to test the model response to NOx emissions. Model performance evaluation of the two WRF-Chem configurations will be presented together with modeled sensitivity of O3 to NOx. Plans for post-campaign model-based analysis and CTM optimization will be presented. The perturbation of a 50% reduction in the NOx emissions allows for the evaluation of NOx and its contribution to the ozone concentration. Through extensive testing of the model’s configuration WRF-Chem was optimized to provide insight to ozone, NOx, VOC, formaldehyde, nitric acid, and other various air pollutants during the campaign.