Summertime Response of Air Emissions to Ambient Temperature in the Eastern United States Over the Years 2005-2013

This study observes the relationship of power plant air emissions of pollutant compounds (CO2, SO2, and NOx) and daily, ambient surface temperature. Greater average daily surface temperatures lead to greater energy demand, which in turn leads to increased emissions from the power plants meeting increased demand. We observe two meter above the surface temperatures using the North American Regional Reanalysis (NARR) and continuously monitored or calculated out-of-the-stack emissions from the EPA's Clean Air Markets database (CAMD) of power plant emissions, over the summers of 2007 through 2012 in the state of Ohio, Kentucky, and Indiana, along with EPA Regions 1, 2 and 3. Summer season is defined as May 1st through September 30th. Each pollutant reacts differently to changes in average state temperature. SO2 sensitivity to temperature is less important than the simple year-over-year reduction in emissions due to State Implementation Plans (SIPs). CO2 and NOx relationships with temperature vary according to region. While increases in emissions with increased temperature in the summer season is observed in all regions of the study, a positive linear relationship cannot be assumed. Different regions react differently to equal changes in temperature. A polynomial function relationship can be created for each region and pollutant. Air quality and emissions forecasting can be evaluated against these observations, and the relationship between temperature and NOx emissions may be useful in evaluating emissions reduction tactics throughout the summer season when NOx emissions have the greatest impact on ozone production.