INHERENT OPTICAL-PROPERTIES OF THE OCEAN - RETRIEVAL OF THE ABSORPTION-COEFFICIENT OF CHROMOPHORIC DISSOLVED ORGANIC-MATTER FROM AIRBORNE LASER SPECTRAL FLUORESCENCE MEASUREMENTS

The absorption coefficient of chromophoric dissolved organic matter (C DOM) at 355 nm has been retrieved from airborne laser-induced and wate r Raman-normalized CDOM fluorescence. Four combined airborne and ship field experiments have demonstrated that (1) the airborne CDOM fluores cence-to-water Raman ratio is linearly related to concurrent quinine-s ulfate-standardized CDOM shipboard fluorescence measurements over a wi de range of water masses (coastal to blue water); (2) the vicarious ca libration of the airborne fluorosensor in units traceable to a fluores cence standard can be established and then maintained over an extended time period by tungsten lamp calibration; (3) the vicariously calibra ted airborne CDOM fluorescence-to-water Raman ratio can be directly ap plied to previously developed shipboard fluorescence-to-absorption alg orithms to retrieve CDOM absorption; and (4) the retrieval is not sign ificantly affected by long-path multiple scattering, differences in at tenuation at the excitation and emission wavelengths, or measurement i n the 180 degrees backscatter configuration. Airborne CDOM absorption measurements will find immediate application to (a) forward and invers e modeling of oceanic water-leaving radiance and (b) validation of sat ellite-retrieved products such as CDOM absorption.