Available scientific evidence has established the fact that meteorology plays an important role in determining whether or not a region meets National Ambient Air Quality Standards (NAAQS) set by Environmental Protection Agency (EPA). This implies that there is a need to account for climate change while moving forward with the future air quality planning in the United States.
This thesis research is focused on analyzing the long term trends in meteorological parameters like wind speed, tropopause height, temperature extremes and growing season length for three Midwestern cities including Indianapolis, Indiana, Cincinnati, Ohio, and Little Rock, Arkansas in the continental U.S. These cities were chosen because their topography is relatively flat and unaffected by large mountain ranges or other topographical features; they represent important regional economic centers; and, have all undergone major air quality management efforts over the past 35 years in order to attempt to meet the NAAQS. The data was obtained from the National Climatic Data Center (NCDC) from 1940’s to present. For the tropopause height analysis, the study region consisted of 7 cities in Midwest and south east coast of US.
Analysis of wind data indicates a significant increase in the frequency of calms over the past 60 years. Temperature analysis revealed warming trends in the region with increased daily maximum and minimum temperature, increased growing season length and a decrease in number of frost days particularly during the period 1976-2009. The trend in the height of tropopause seems to be of cyclic nature with alternate decades of increase and decrease.
Increases in the frequency of calms would affect ozone distribution patterns and would ventilate pollutants from these areas less effectively which could be problematic from a human health point of view, particularly for asthmatics. Increase in temperature may lead to increased natural production of ozone precursors (VOCs and NOx).
Finally, we provide an overview of the processes by which climate change can effect emissions from natural and anthropogenic sources and how the variations in climate – biosphere interaction can affect pollutant concentrations.