Spectrally Resolved Ocean Optics in the Vicinity of COVE Site

Radiative transfer at the air-sea interface plays a significant role in the global climate system. Investigations of radiation to date have tended to focus on one of the two media (atmosphere or ocean) explicitly, regarding the other as a simple boundary condition or correction factor in remote sensing. Our analysis with the CERES Ocean Validation Experiment (COVE) treats both media explicitly using thorough measurements and coupled radiative transfer theory. Long-term observations at the rigid COVE sea platform are sponsored by the Clouds and the Earth's Radiant Energy System (CERES) program of NASA's Earth Observing System (EOS). We show data from the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS), which was a field campaign (June - August, 2001) at COVE, and from the summer of 2002. Analytical Spectral Devices spectroradiometers on board the NASA Langley OV-10 aircraft measured both downwelling and upwelling irradiances (350 - 2250 nm with an effective resolution of 8-12 nm interpolated to 1 nm); spectral albedo is readily obtained. In addition to calibration using data provided by the manufacturer, a second inter-instrument calibration was conducted using the same sources: outdoor solar radiation and an indoor 1000-W QTH lamp with 8" integrating sphere applied to both the uplooking and downlooking instruments. The albedo of the ocean surface is a function of numerous variables; some are hard to measure. A Coupled Ocean-Atmosphere Radiation Transfer (COART) model based on Discrete Ordinate Radiation Transfer (DISORT) has been developed by Z. Jin. COART has been used to compute the spectral albedo of the ocean surface under various conditions. The measured data show reasonable agreement with the COART model results.