Weather and Air Quality Forecasts and Observations for the OWLETS Campaign

As an EPA regulated criteria pollutant, tropospheric ozone is of interest due to its adverse effects on lung functionality and crop yield. The National Aeronautics and Space Administration (NASA) Tropospheric Emissions: Monitoring of Pollution (TEMPO) mission is the first geostationary satellite that will take hourly measurements to monitor air pollutants across North America using solar backscatter. In summer 2017, the TEMPO Student Collaboration team participated in the Ozone Water-Land Environmental Transition Study (OWLETS) campaign that studied how meteorological conditions such as the planetary boundary layer height (BLH), sea breeze, and cloud coverage influenced ozone concentrations over land and water bodies. This will provide information on land-water gradients to help improve forecast model predictions and air quality satellite retrievals, such as for TEMPO. The team utilized collocated in situ and remote sensing measurements at multiple land-based locations across Hampton Roads and at the water-based Chesapeake Bay Bridge Tunnel (CBBT) in order to study the differences between the land-water interfaces. Spatial measurements in the horizontal plane were taken using ground stations (NASA and Virginia Department of Environmental Quality) and mobile ozone monitors. Vertical profiles of ozone and meteorological parameters were obtained from ozonesondes. The days of interest during the campaign were July 19, 20, and 21 due to a significant blocking high-pressure event over the southeastern region of the U.S. Forecasts were made prior to measurement days using weather and air quality models and were later analyzed compared to observed data (i.e. METAR and buoy reports, sonde profiles, and ground measurements). It was hypothesized that the ozone mixing ratios over the bay during a high-pressure event were higher than mixing ratios over the mainland due to the shallow marine boundary layer, lower ozone deposition over water, and the pollution transport from sea breeze circulations. Measurements taken during this case study showed interesting preliminary results in regards to possible sea breeze interactions and BLH differences.