Ozone is toxic to living organisms and is considered a major air pollutant.
Despite considerable regulatory and pollution control efforts over the past 30 years, high ozone concentrations in urban, suburban, and rural areas of the United States continue to be a major environmental and health concern. Ozone in the lower atmosphere is also a greenhouse gas that contributes to global warming and climate change. Observations are needed to improve our understanding of the processes leading to ozone pollution and to implement more effective control mechanisms. It is important to monitor ozone concentrations not only at the surface but also in the lower atmosphere, because vertical and horizontal transport of ozone can have a major impact on surface ozone concentrations. Ozone DIALs are active remote sensors that are capable of measuring ozone concentrations in the atmosphere with high temporal and spatial resolution.