Impacts of Bubbles on Optical Estimates of Calcium Carbonate in the Great Calcite Belt

Abstract

In this MSc thesis I determine if wind-generated bubbles elevated measurements of above-water normalized water-leaving radiance (nLw) and subsequent remote sensing estimates of particulate inorganic carbon (PIC) in a coccolithophore bloom on the Patagonian Shelf. Although no measurements were made of bubbles, shipboard wind speed was used as a proxy for bubble backscattering. An empirical orthogonal function (EOF) analysis was performed on nLw. The first EOF accounted for 95% of the variance, and was attributed to changes in spectral amplitude. Scores of the first EOF were positively correlated with flow-through PIC backscattering (bb′) > 5x10-4 m-1, indicating that above this threshold PIC was an optically active seawater constituent. There was only evidence for a bubble elevation of nLw at values of bb′ < 5x10-4 m-1 and wind speeds > 12.5 m s-1. There was no evidence for a bubble elevation of PIC estimated using the two-band PIC algorithm.