Development of a consistent multi-sensor global ocean colour time series

The advent of a new generation of space-borne ocean colour sensors brings the prospect of global ocean measurements for decades into the future. These measurements will provide the basis for characterizing variability in the structure of the ocean's phytoplanktonic communities and the response of those communities to climatic change. In addition, the measurements will allow development of the scientific basis necessary to manage the sustainable resources of marine ecosystems. These studies will require a merged, long-term, multi-satellite ocean colour time series extending beyond the operational lifetimes of individual instruments. The Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project has been tasked to develop the tools required to create this time series. Among these tools are a comprehensive in situ (field collected) bio-optical dataset for validating ocean optics algorithms and associated models of oceanic properties; a programme to evaluate different atmospheric correction techniques; a programme to link the calibrations of individual satellite instruments; a programme to develop consistent calibration and validation datasets for satellite instruments; and a set of alternate methods to combine ocean colour measurements from different sources into a single time series. We report on the progress of this development work by the SIMBIOS Project.