Airborne remote sensing of submesoscale dynamics and phytoplankton

This work is in press in AGU's 'Earth and Space Science. Please see embedded PDF at end for paper.<\bold> Abstract: Submesoscale dynamics can induce significant vertical fluxes of phytoplankton, nutrients, and carbon, resulting in biological and climatological impacts such as enhanced phytoplankton production, phytoplankton community shifts, and carbon export. However, resolving these dynamics is challenging due to their rapid evolution (hours to days) and small spatial scales (1-10 km) of variability. The Modular Aerial Sensing System (MASS), an airborne instrument package measuring concurrent ocean dynamics and hyperspectral ocean color, provides a powerful tool to study the influence of submesoscale dynamics on phytoplankton and carbon. In this study, we present the first airborne observations pairing snapshots of sub-kilometer ocean velocities and their derivatives (i.e. vorticity, divergence, and strain) with concurrent ocean color and sea surface temperature. We developed airborne proxies of chlorophyll-a and particulate organic carbon, which explained about 66.2% and 56.2% of in situ variability without atmospheric correction, suggesting that MASS can capture phytoplankton variability. We also explored relationships between concurrent vorticity, divergence, strain, sea surface temperature, chlorophyll-a, and hyperspectral variables to illuminate the submesoscale processes that alter phytoplankton distributions. This study demonstrates the value of merging bio-optical and physical airborne remote sensing data to better understand the influence of submesoscale dynamics on oceanic ecosystems and organic carbon. We highlight the potential for suborbital remote sensing for studying processes that impact phytoplankton ecosystems and carbon transport without the spatiotemporal aliasing affecting in situ sensors.

overview of study region, plane lines, chl-a and SST variability

</picture> </figure> --> plane schematic

</picture> </figure> --> co-located physical and bio measurements

</picture> </figure> --> Example of 2 features of interest, aligning convergence/divergence features with ocean color

</picture> </figure> --> schematic

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