NASA HQ supported an oceanographic field campaign in Chesapeake Bay this summer to coincide with the NASA DISCOVER AQ (Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality) EV-1 project managed by LARC and GSFC. The Chesapeake Bay oceanographic cruise was led by Dr. Antonio Mannino/NASA-GSFC 614.2 (Chief Scientist) and Dr. Maria Tzortziou/University of Maryland-GSFC (co-Chief Scientist). Among the main objectives of the CBODAQ campaign was to obtain detailed atmospheric and oceanographic observations for characterizing short-term dynamics and spatio-temporal variability in atmospheric and coastal ecosystem processes. These observations will assist NASA's GEO-CAPE (Geostationary for Coastal and Air Pollution Events) Decadal Survey mission science working group to further develop measurement and instrument requirements for the ocean ecosystem portion of the GEO-CAPE mission. Several sampling modes were accomplished during the field campaign to address GEO-CAPE science objectives including (1) transects - sampling a series of stations along a gradient (north to south, river tributary to open waters of the bay, marsh creek to open bay), (2) sampling a water mass throughout a day by following a surface drifter (built and tracked by the University of New Hampshire) and (3) sampling the same location throughout a day. The NOAA SRVx National Marine Sanctuary Test and Evaluation Vessel operated by Cardinal Point Captains LLC was used for the field campaign. More than 25 scientists, 4 undergraduate interns, 1 high school intern, and 2 graduate students from NASA/GSFC, NOAA, University of Maryland, University of New Hampshire, University of South Florida, Old Dominion University, East Carolina University, Smithsonian Environmental Research Center (SERC), Johns Hopkins University, Sigma Space Corporation and University of Maryland Baltimore County (UMBC) participated in the oceanographic field campaign. Other NASA/GSFC participants included Dirk Aurin (614.2/SSAI), Rob Jenkens (614.2/SIES intern) and Stan Hooker (614.2). The NASA P3B airplane equipped with instrumentation to measure aerosol and trace gas concentrations can be seen conducting spirals over the NOAA SRVx ship. Just to the right of the airplane are 3 sensors (1. Pandora for measuring atmospheric aerosol and trace gas constituents such as ozone and nitrogen dioxide, 2. a UV-Vis-NIR solar reference for an in-water profiling radiometer and 3. UV-Vis-NIR solar reference cluster with shadow band for an in-water profiling radiometer ; C-OPS). Oceanographic Observations Two in-water profiling radiometers, C-OPS (GSFC; Biospherical Scientific) and HyperPro (NOAA), were deployed to estimate the water-leaving radiances in the UV-Vis-NIR spectral range. An above-water radiometer was also employed to measure water-leaving radiances in the UV-Vis-NIR (University of South Florida). An inherent optical properties package with a suite of optical sensors was deployed to compute in-water profiles of spectral particle and dissolved absorbance, particle volume scattering function, fluorescence by chlorophyll and dissolved matter, as well as salinity and temperature (East Carolina University). An underway seawater instrument package measured surface concentrations of pCO2, dissolved oxygen, sea-surface temperature, salinity, turbidity and fluorescence by chlorophyll and dissolved matter (University of New Hampshire). Seawater samples were collected at multiple depths by deploying Niskin-type bottles. Primary production experiments were conducted on the ship daily with collected seawater samples (Old Dominion University). Laboratory analyses of the seawater samples include phytoplankton pigments (GSFC), fluorometric chlorophyll-a, pCO2, dissolved inorganic carbon, alkalinity, dissolved organic carbon and nitrogen (GSFC), particulate organic carbon and nitrogen (GSFC), nutrients, absorbance of colored dissolved organic matter (CDOM; GSFC, University of South Florida), fluorescence of CDOM (University of Maryland), absorbance of particles (University of South Florida), and suspended particulate matter (GSFC). The most dramatic event was the observation of dozens of dead striped bass fish in the upper Bay near Annapolis, which appears to be related to the very low levels of dissolved oxygen in the bay. The zodiac expedition to sample Fishing Bay which is surrounded by the Blackwater Wildlife Refuge to study the inputs of wetland vegetation organic matter into Chesapeake Bay. Participants included Stan Hooker (614.2), John Morrow (Biospherical Sciences), Vienna Saccomanno (SERC summer intern) and Paul Brooks (crew member of NOAA SRVx). Atmospheric Observations Several atmospheric sensors were employed on the NOAA SRVx. A new modified Pandora sensor (using feedback from a digital camera to the sun-tracker) was used for continuous measurements of atmospheric trace gases (total column NO2, O3, SO2) from the boat (University of Maryland, GSFC). A set of analytical instruments continuously collected and monitored ozone, NO, and NOy levels within the marine boundary layer (University of Maryland). A micropulse lidar was installed on the evening of July 15th to conduct measurements of aerosols and clouds including aerosol and cloud layer heights (Sigma Space; completed image posted daily to the Disc AQ daily quicklook table under "MPLs", at: https://www-air.larc.nasa.gov). Air samples were collected throughout each day for laboratory analysis of aerosols including water-soluble organics and inorganic ions as well as measurements of methane, CO2, and N2O (University of New Hampshire). One Microtops Ozonometer and two Microtops sunphotometers were used for measurements of total column ozone and aerosol optical thickness (AOT) in the spectral range of 340-936 nm (University of Maryland) (data will be made available through the AERONET/Marine Aerosol Network) During four flight days of the DISCOVER AQ activity, the NOAA SRVx was positioned to sample in the upper bay (between Baltimore and south of Annapolis) to provide ground-truth data for DISCOVER AQ. These airplanes (UC-12 and P3B) conducted several passes over the ship location each day including some spiral flight tracks by the P3B directly over the ship. The observations collected by DISCOVER AQ will also be applied for ocean color analyses including the ACAM sensor (UV-Vis radiometer; GSFC) and the HSRL (LARC lidar). Russ Dickerson's team (UMCP) also flew their Cessna 402 B near the ship during our transit further south in the bay.