Calcium carbonate measurements in the surface global ocean based on Moderate-Resolution Imaging Spectroradiometer data

Abstract

We describe a two-band algorithm for the remote quantification of the ocean's suspended calcium carbonate (also known as particulate inorganic carbon (PIC)), based on normalized water-leaving radiance at 440 and 550 run. We tested this algorithm using ship-derived and satellite-derived results from a variety of marine environments. From this validation work we calculated the overall accuracy of the satellite-based PIC estimates, assuming different timescales and space scales for binning. After performing the validation work we applied the two-band algorithm to water-leaving radiance data from 2002, sampled by Moderate-Resolution Imaging Spectroradiometer (MODIS)/Terra (a 36-band satellite spectrometer designed to observe land, ocean, and atmosphere), and we derived seasonal, global maps of the standing stock of pelagic PIC as well as particulate organic carbon (POC). These data, along with limited observations on the turnover time of calcium carbonate coccoliths in the euphotic zone, provide some new insights into global rates of pelagic calcite production. Copyright 2005 by the American Geophysical Union.