Diurnal and Land Breeze Effects on Ozone Concentrations Along Southern Lake Michigan
Location
Alumni Hall South
Department
Environmental Science
Abstract
Ozone (O3) is a natural and anthropogenic gas that occurs in the Earth’s stratosphere and troposphere. Ozone in the stratosphere is formed naturally through the interaction of solar ultraviolet (UV) radiation and molecular oxygen (O2). Stratospheric ozone absorbs and protects us from most of the ultraviolet radiation that the sun emits, whereas ozone in the troposphere is harmful to those that breathe it in. Tropospheric ozone is formed primarily from photochemical reactions between two major classes of air pollutants, volatile organic compounds (VOCs) and nitrogen oxides (NOx). These pollutants are important precursors for ozone production and are cycled by the diurnal effect and land breeze. Lake Michigan’s coastal region is seasonally impacted by episodes of high ozone concentrations that are influenced by meteorology and the transport of pollutants. The 2017 Lake Michigan Ozone Study - Preliminary Finding Report was used as a reference for our research. The objective of our research was to assess spring and summer ozone concentrations while examining how ozone is influenced by land breeze and the diurnal cycle. Our area of study included a sequence of counties surrounding Lake Michigan from Gary, Indiana to Milwaukee, Wisconsin. We obtained ozone, UV, and ozone precursor data from the US EPA Air Quality System (AQS). We used R and RStudio to visualize these air-quality data sets. The two highest days of ozone concentrations between 2017 and 2020 at Gary, Indiana and Milwaukee, Wisconsin were plotted including O3, NO2, UV, and wind. Ozone concentration levels were elevated throughout May and September from 2017 to 2020. We found that ozone concentrations in counties around Lake Michigan have exceeded the National Air Quality Standards under the Clean Air Act provided by the EPA. Our research supports the claim that the diurnal cycle and lake breeze affect ozone concentration in the surrounding counties of Lake Michigan. This study provides us with information regarding diurnal patterns of ozone concentrations and an explanation for why areas bordering Lake Michigan sometimes experience unsafe levels of ozone.
Faculty Sponsor
Gregory Anderson, Northeastern Illinois University
Diurnal and Land Breeze Effects on Ozone Concentrations Along Southern Lake Michigan
Alumni Hall South
Ozone (O3) is a natural and anthropogenic gas that occurs in the Earth’s stratosphere and troposphere. Ozone in the stratosphere is formed naturally through the interaction of solar ultraviolet (UV) radiation and molecular oxygen (O2). Stratospheric ozone absorbs and protects us from most of the ultraviolet radiation that the sun emits, whereas ozone in the troposphere is harmful to those that breathe it in. Tropospheric ozone is formed primarily from photochemical reactions between two major classes of air pollutants, volatile organic compounds (VOCs) and nitrogen oxides (NOx). These pollutants are important precursors for ozone production and are cycled by the diurnal effect and land breeze. Lake Michigan’s coastal region is seasonally impacted by episodes of high ozone concentrations that are influenced by meteorology and the transport of pollutants. The 2017 Lake Michigan Ozone Study - Preliminary Finding Report was used as a reference for our research. The objective of our research was to assess spring and summer ozone concentrations while examining how ozone is influenced by land breeze and the diurnal cycle. Our area of study included a sequence of counties surrounding Lake Michigan from Gary, Indiana to Milwaukee, Wisconsin. We obtained ozone, UV, and ozone precursor data from the US EPA Air Quality System (AQS). We used R and RStudio to visualize these air-quality data sets. The two highest days of ozone concentrations between 2017 and 2020 at Gary, Indiana and Milwaukee, Wisconsin were plotted including O3, NO2, UV, and wind. Ozone concentration levels were elevated throughout May and September from 2017 to 2020. We found that ozone concentrations in counties around Lake Michigan have exceeded the National Air Quality Standards under the Clean Air Act provided by the EPA. Our research supports the claim that the diurnal cycle and lake breeze affect ozone concentration in the surrounding counties of Lake Michigan. This study provides us with information regarding diurnal patterns of ozone concentrations and an explanation for why areas bordering Lake Michigan sometimes experience unsafe levels of ozone.