These data are maps of remotely sensed chlorophyll observations starting in 1990. The data were obtained using the Ocean Data Acquisition System (ODAS), an ocean color instrument developed by NASA. ODAS consists of 3 radiometers in the blue-green region of the visible spectrum that measure water-leaving radiance at 460, 490 and 520 nm. This region of the spectrum is responsive to changes in concentrations of chlorophyll. The instrument package also includes a Loran-C that acquires navigation data, an infrared sensor to measure sea surface temperature, and an on-board computer to log the data.
In 1996, a new instrument, the SeaWiFS Aircraft Simulator (SAS II), was used in parallel with the ODAS instrument. SAS II contains sensors at 7 wavebands, including the 6 visible bands of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite ocean color instrument. The additional bands of SAS II allows improved recoveries of chlorophyll in highly turbid conditions or at the extremely high concentrations that accompany red tides. SAS II also gives data unaffected by the atmosphere for comparison with satellite data and thus serves as a way to validate SeaWiFS data for Chesapeake Bay. Map images of chlorophyll for 1996 and later were generated from SAS II data.
Measurements by both ODAS and SAS instruments are made in low altitude (150 meters) surveys using small aircraft, such as the De Havilland "Beaver" which was operated by the Virginia Institute of Marine Science, or newer aircraft including a Piper Aztec and Cessna 172 Skyhawk. A set of flight tracks encompassing the Bay is sampled 1-2 times per week. Over 200 flights with ODAS were made over the Chesapeake Bay and additional 200 flights using SAS instruments since the inception of the program. The first year of the program in 1989 focused on developing algorithms for recovering chlorophyll concentrations by coordinating ship and aircraft measurements. Since 1990, regular series of 25-30 flights per year have been conducted, spanning the most productive parts of the year. [This summary was derived from the NOAA Chesapeake Bay Office WWW page.]
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NOAA Chesapeake Bay Office, website for Study of Phytoplankton Blooms in the Chesapeake Bay using Aircraft Remote Sensing.
NOAA CHESAPEAKE BAY OFFICE Phone:
derek.orner at noaa.gov
NOAA Chesapeake Bay Office
410 Severn Ave., Suite 107A City:
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Synoptic measurements of the distribution of chlorophyll in the Chesapeake Bay using aircraft remote sensing, L.W. Harding, Jr., and E.C. Itsweire, in New Perspectives in the Chesapeake System: A Research and Management Partnership (J. Mihursky and A. Chaney, Eds), 147-160 (1991).
Comparison of phytoplankton biomass estimates for the Chesapeake Bay using aircraft remote sensing and in-situ chlorophyll data, E.C. Itsweire, L.W. Harding, Jr., and L. H. Bahner, in New Perspectives in the Chesapeake System: A Research and Management Partnership (J. Mihursky and A. Chaney, Eds), 161 - 168 (1991).
Determination of Phytoplankton Chlorophyll Concentrations in the Chesapeake Bay with Aircraft Remote Sensing, L.W. Harding, Jr., E.C. Etsweire and W.E. Esaias, Remote Sensing of the Env., 40: 79-100 (1992).
Estimates of Phytoplankton Biomass in the Chesapeake Bay from Aircraft Remote Sensing of Chlorophyll Concentrations, 1989-92, L. W. Harding, Jr., E.C. Itsweire and W.E. Esaias. Remote Sensing of the Env., 49: 41-56 (1994).