A preliminary assessment of the sensitivity of air quality in North Carolina to global change

Climate change and the associated dynamical and physical processes in the atmosphere affect ambient concentrations of air pollutants, and their temporal and spatial distributions, resulting from various sources of natural and anthropogenic emissions. Our understanding of such complex relationship between climate and air quality is key to identify the potential impacts of global change on human health where meteorology and air quality stressors are among the most important metrics of health outcomes. We used a nested global-to-regional scale modeling system to study the effect of changes in future climate and emissions on ozone and particulate matter (PM10 and PM2.5) concentrations in North Carolina. The future year climate change was modeled with the NCAR Community Climate System Model (CCSM) for the IPCC A1B scenario. We performed full dynamic downscaling of the meteorology from CCSM to the regional-scale Weather Research Forecast (WRF) model, and we modeled inter-annual variability by modeling 3 years for the base period (2000-2002), and for each of two future year periods (2018-2020 and 2048-2050). We used the EPA National Emissions Inventories (NEI) for the base period, and projected them to the two future-year periods, and used the WRF-SMOKE-CMAQ modeling system over a nested modeling domain at 36/12-km horizontal resolution to model these 9 annual periods. We will present results from changes in ozone, PM10 and PM2.5 levels observed in the Eastern U.S. focusing on several urban areas in North Carolina, due to the changes in future year climate and emissions. In particular we focus our analysis on the effect of the selected horizontal resolution and the corresponding scales on capturing the peak ozone and PM episodes and their spatial and temporal variations. We also examine the relative influence of meteorology and emissions in relation to elevated pollution levels simulated during the three-year base period and the two future three-year periods.