Monte Carlo simulations for interpretation of irradiance measurements from moored instruments: preliminary results

摘要

Abstract: The recent development of moorable underwater spectral radiometers provides the possibility of long-term observations of bio-optical properties of the ocean at a sampling frequency of a few seconds to minutes. However, interpretation of the observed attenuation coefficients in terms of variations in the inherent optical properties (IOPs) or the biological properties is not straightforward for several reasons. First, even in a homogeneous ocean the attenuation coefficient K$-d$/ will be a function of depth, illumination at the surface, and the surface roughness, as well as the IOPs of the ocean. Next, a moored instrument cannot measure K$-d$/ as a function of depth but instead measures the mean K$-d$/ between discrete depths. Finally, K$-d$/ will depend on the (unknown) vertical structure of the optical properties of the water column. The dependence of the mean K$-d$/ on these factors is studied with Monte Carlo simulations of radiative transfer in the ocean-atmosphere system. Preliminary results from this study are presented. !14