The interaction of sunlight, particularly ultraviolet light, with hydrocarbons and nitrogen oxides, which are emitted by automobiles, gasoline vapors, fossil fuel power plants, refineries, and certain other industries.
You may have heard of the ozone hole problem-that is a lack of ozone in the stratosphere (the 2nd layer of the Earth's atomsphere). But ozone is also found in the troposphere, the first layer of the Earth s atmosphere. In the troposphere, ozone is NOT wanted! It can actually do a lot of damage.  As in the stratosphere, ozone in the troposphere is destroyed by naturally occurring chemical reactions and by reactions involving human-produced chemicals. Tropo-spheric ozone can also be destroyed when ozone reacts with a Ozone is formed throughout the atmosphere in multistep chemical processes that require sunlight. In the stratosphere, the process begins with an oxygen molecule (O 2) being broken apart by ultraviolet radiation from the Sun. In the lower atmos phere (troposphere), ozone is formed by a different set of chemical reactions that involve naturally occurring gases and those from pollution sources. Tropospheric ozone. Near Earth’s surface, ozone is produced by chemical reactions involving naturally occur-ring gases and gases from pollution sources. Ozone produc-tion reactions primarily involve hydrocarbon and nitrogen oxide gases, as well as ozone itself, and all require sunlight for completion. 1 Ozone is a naturally occurring gas found in the troposphere and other parts of the atmosphere. 2  Tropospheric ozone is often called bad ozone because it can damage living tissue and break down certain materials. 3  Concentrations of ozone are not uniform in the troposphere. The general concepts found in this section include the following: 1  Ozone is a naturally occurring gas found in the troposphere and other parts of the atmosphere. 2  Tropospheric ozone is often called bad ozone because it can damage living tissue and break down certain materials. 3  Concentrations of ozone are not uniform in the troposphere. 4  Longer 5  ... T Ozone (O 3) is a constituent of the troposphere (it is also an important constituent of some regions of the stratosphere commonly known as the ozone layer). The troposphere extends from the Earth 's surface to between 12 and 20 kilometers above sea level and consists of many layers. Ozone is more concentrated above the mixing layer, or ground layer. Ground-level ozone, though less concentrated than ozone aloft, is more of a problem because of its health effects. Photochemical and chemical reactions involving it drive many of the chemical processes that occur in the atmosphere by day and by night Ozone is formed from dioxygen by the action of ultraviolet light and also atmospheric electrical discharges, and is present in low concentrations throughout the Earth's atmosphere (stratosphere). In total, ozone makes up only 6993600000000000000♠0.6 ppm of the atmosphere.  It protects both plants and animals from the sun's harmful ultraviolet rays. In the troposphere (lower atmosphere) however, ozone is a troublemaker being both a pollutant and a greenhouse gas. In the troposphere it can be harmful to health. Here, ozone is formed by a very different process. Oxides of nitrogen and reactive organic compounds react together in the presence of sunlight.  Tropospheric ozone is formed by the interaction of sunlight, particularly ultraviolet light, with hydrocarbons and nitrogen oxides, which are emitted by automobiles, gasoline vapors, fossil fuel power plants, refineries, and certain other industries. The general concepts found in this section include the following: 1  Ozone is a naturally occurring gas found in the troposphere and other parts of the atmosphere. 2  Tropospheric ozone is often called bad ozone because it can damage living tissue and break down certain materials. 3  Concentrations of ozone are not uniform in the troposphere. 4  Longer 5  ... T Tropospheric ozone is a greenhouse gas and initiates the chemical removal of methane and other hydrocarbons from the atmosphere. The troposphere extends from the Earth 's surface to between 12 and 20 kilometers above sea level and consists of many layers. Ozone is more concentrated above the mixing layer, or ground layer. Ground-level ozone, though less concentrated than ozone aloft, is more of a problem because of its health effects. Stratospheric ozone is formed naturally by chemical reactions involving solar ultraviolet radiation (sunlight) and oxygen molecules, which make up 21% of the atmosphere. In the first step, solar ultraviolet radiation breaks apart one oxygen molecule (O 2) to produce two oxygen atoms (2 O) (see Figure Q2-1). Tropospheric ozone. Near Earth’s surface, ozone is produced by chemical reactions involving naturally occur-ring gases and gases from pollution sources. Ozone produc-tion reactions primarily involve hydrocarbon and nitrogen oxide gases, as well as ozone itself, and all require sunlight for completion. Ozone is formed in the troposphere by various chemical reactions involving a combination of the oxides of nitrogen, reactive volatile organic compounds (VOC) produced by a combination of exhaust from automobiles in the form of unburned hydrocarbons, and diatomic oxygen in the presence of sunlight (Figure 12). 
http://www.windows2universe.org/earth/Atmosphere/ozone_tropo.html http://www.esrl.noaa.gov/csd/assessments/ozone/2010/twentyquestions/Q2.pdf https://www.ucar.edu/learn/1_7_1.htm https://en.wikipedia.org/wiki/Tropospheric_ozone https://en.wikipedia.org/wiki/Ozone http://epa.tas.gov.au/epa/tropospheric-ozone https://www.ucar.edu/learn/1_7_1.htm https://en.wikipedia.org/wiki/Tropospheric_ozone http://www.esrl.noaa.gov/csd/assessments/ozone/2010/twentyquestions/Q2.pdf http://www.meteor.iastate.edu/gccourse/chem/nitro/ozone2.html
how is tropospheric ozone formed