Inherent optical properties of the ocean: retrieval of the absorption coefficient of chromophoric dissolved organic matter from airborne laser spectral fluorescence measurements

Appl Opt. 1995 Oct 20;34(30):7032-8. doi: 10.1364/AO.34.007032.

Abstract

The absorption coefficient of chromophoric dissolved organic matter (CDOM) at 355 nm has been retrieved from airborne laser-induced and water Raman-normalized CDOM fluorescence. Four combined airborne and ship field experiments have demonstrated that (1) the airborne CDOM fluorescence-to--water Raman ratio is linearly related to concurrent quinine-sulfate-standardized CDOM shipboard fluorescence measurements over a wide range of water masses (coastal to blue water); (2) the vicarious calibration of the airborne fluorosensor in units traceable to a fluorescence standard can be established and then maintained over an extended time period by tungsten lamp calibration; (3) the vicariously calibrated airborne CDOM fluorescence-to-water Raman ratio can be directly applied to previously developed shipboard fluorescence-to-absorption algorithms to retrieve CDOM absorption; and (4) the retrieval is not significantly affected by long-path multiple scattering, differences in attenuation at the excitation and emission wavelengths, or measurement in the 180° backscatter configuration. Airborne CDOM absorption measurements will find immediate application to (a) forward and inverse modeling of oceanic water-leaving radiance and (b) validation of satellite-retrieved products such as CDOM absorption.