OCEANIC PRIMARY PRODUCTION ESTIMATES FROM MEASUREMENTS OF SPECTRAL IRRADIANCE AND PIGMENT CONCENTRATIONS

A major objective of biological oceanography today is to quantify the mean and the variance of phytoplankton production on a global basis. Synoptic satellite sensing of the world's ocean is essential to this effort which requires contemporaneous sea surface data to provide complete water column information. Toward these objectives we present a spectrally dependent bio-optical model for the computation of in situ phytoplankton production. Using this model we show that in situ phytoplankton production can be accurately estimated from measurements of incident spectral irradiance and phytoplankton pigment concentrations. We also present estimates of photosynthetically absorbed radiation as a function of wavelength for a natural phytoplankton population. These complete spectral data provide insight into the wavelength-dependent utilization of radiant energy by phytoplankton and the influence of phytoplankton on the optical properties of the water column. We show that the model can be used for shipboard observations and that it may be especially useful for predicting production rates from data provided by untended buoys.