Assessment of Ozone Soundings during the Summer of 2019 Air Quality Exceedances in Baltimore, Maryland

The Atmospheric Lidar Group (https://alg.umbc.edu) at the University of Maryland, Baltimore County (UMBC) contribute to the Maryland Department of the Environment (MDE) Air Quality Monitoring Program effort to understand the transport of particulates and air pollutants (from both natural and anthropogenic sources) and their impact on the regional variability of ozone (O₃) and fine particulate matter (PM_2.5) for the last 12 years. A total of 14 ozone soundings were launched in the summer of 2019 during forecasted air quality exceedances. Maximum 8-hr ozone surface concentrations in Maryland during these 10 air quality events ranged between 74 to 85 ppbv. Ozone profiles were obtained from soundings taken with the I-Met sounding systems. Balloon-borne electrochemical concentration cell (ECC) ozonesondes were used to generate vertical profile of aloft ozone concentrations to better understand the aloft “ozone reservoir”. In addition to ozonesondes, rawinsondes will be launched to record aloft relative humidity, water vapor, temperature, and wind speed and wind direction. These aloft meteorological measurements will be of great importance as they will be used to determine the vertical make-up of the boundary layer and help in determining the potential presence of temperature inversions and the impact of other meteorological parameters to surface ozone concentrations.