Overview of the 2017 OWLETS: Summary of Observations and Initial Results

The monitoring of ozone (O₃) in the troposphere is of pronounced interest due to its known toxicity and health hazard as a photo-chemically generated pollutant. One of the major difficulties for the air quality modeling, forecasting and satellite communities is the validation of O₃ levels in sharp transition regions, as well as near-surface vertical gradients. Land-water gradients of O₃ near coastal regions can be large due to differences in surface deposition, boundary layer height, and cloud coverage. Observations in horizontal and vertical directions over the Chesapeake Bay are needed to better understand O₃ formation and redistribution within regional recirculation patterns. The O₃ Water-Land Environmental Transition Study (OWLETS) was a field campaign conducted in the summer 2017 in the VA Tidewater region to better characterize O₃ across the coastal boundary. To obtain over-water measurements, the NASA Langley Ozone Lidar as well as supplemental measurements from other sensors (e.g. Pandora, AERONET) were deployed on the Chesapeake Bay Bridge Tunnel (CBBT) 7-8 miles offshore. These observations were complimented by NASA Goddard’s Tropospheric Ozone Lidar along with ground-based measurements over-land at the NASA Langley Research Center (LaRC) in Hampton, VA. On measurement days, time-synchronized data were collected, including launches of ozonesondes from CBBT and LaRC sites that provided additional O₃, wind, and temperature vertical distribution differences between land and water. These measurements were complimented with: in-situ O₃ sensors on two mobile cars, a micro-pulse lidar at Hampton University, an in-situ O₃ sensor on a small UAV-drone, and Virginia DEQ air-quality sites. Two aircraft and a research vessel also contributed to OWLETS at various points during the campaign: the NASA UC-12B with the GeoTASO passive remote sensor, the NASA C-23 with an in-situ chemistry analysis suite, and a SERC research vessel with both remote and in-situ sensors. This combination of observations provided a unique 4-D (horizontal, vertical, and time) view of O₃ to help provide feedback to air quality forecast models as well as future satellite remote sensing systems such as NASA’s TEMPO mission. In this presentation, a summary of observations and initial results will be presented from the OWLETS campaign.