Complementary use of Wave Glider and satellite measurements: Description of spatial decorrelation scales in Chl-a fluorescence across the Pacific basin

A key challenge for ecosystem science in the 21st century is to characterize emerging trends in ecosystem productivity due to climate change and to better predict cycles in ecosystem variability. A first step toward this goal is to be able to characterize phytoplankton variability across a wide range of spatial and temporal scales. In this paper, 15 months of Wave Glider (WG) fluorometer measurements made across the Pacific Ocean were used to understand how WGs complement existing chlorophyll-a-based measurements of phytoplankton biomass from satellite platforms. Extensive analysis of the WG transects demonstrated that WG fluorometer readings reliably characterized similar large-scale variability in satellite Chl-a measurements in four distinct ecosystem types including coastal upwelling, transition zone, oligotrophic and equatorial upwelling regions. Complementary information provided by WG measurements included better resolution of coastal Chl-a patches and prominent diel cycles in the open ocean. The decorrelation scales computed from WG fluorometer measurements in this study provide necessary information for designing observing systems, process experiments, and data assimilation studies. We conclude this paper by suggesting how WGs can be used to anchor satellite measurements and to develop better predictive models.