Estimating ocean primary production from satellite chlorophyll. Introduction to regional differences and statistics for the Southern California Bight

Abstract

The prospect of estimating primary production (II, mg C m −2 d −1 ) from chlorophyll pigment concentrations (C k , mg m −3 near the ocean surface is appealing, now that chlorophyll concentrations can be extracted from satellite images. Earlier work has shown a proportionality between II and C k (II αF·C k ) but with large variance in the proportionality factor F. A cursory overview of global data suggests part of this variability is regional. For example, F for subtropical open ocean regions exceeds that of temperate coastal regions. In the richest waters, F approaches a minimum limit value, of ∼100(mg C m −2 d −1 )(mg C k m −3 ) −1 . Some of the variability in the relation over time and space in the Southern California Bight is related to environmental variables. In the simplest systems, F is proportional to insolation. The variability in F may be of ecological interest beyond its utility in relating water column production to near-surface chlorophyll as an additional descriptive characteristic of pelagic ecosystems.