Posters

Poster Session 2, Tuesday,  October  4, 10:40–12:40

Poster 38

Investigating biophysical interactions across the Gulf Stream front via fine-scale optical measurements

The overarching goal of this work is to better understand the impact of fine scale (0.1-10km) ocean physics on phytoplankton biomass and diversity. By the very nature of the scale at which these processes operate, they are missing from global models and coarse remote sensing products. Yet they may be an important part of the physical dynamics that power the ocean’s biological carbon pump, sustain the foundation of marine ecosystems, and maintain phytoplankton diversity. We conducted four cruises across the Gulf Stream front just downstream of the current’s separation point at Cape Hatteras, N.C. We collected above-water radiometry from the ship and via aerial drone, continual flow-through based inherent optical properties (IOPs), high performance liquid chromatography, and flow cytometry in coordination with tow-yo profiles of physical properties at high resolution. In this presentation we will share early results, focused on products retrieved from IOPs and radiometry, describing the observed biophysical environment and comparing summer and winter conditions. We found unexpected increases in mean particle size in more oligotrophic Gulf Stream waters compared to shelf water, shifts in absorption spectra and backscattering ratio in micro-upwelling patches, spikes in chlorophyll-a at sharp density gradients, thin “waterfalls” under the Gulf Stream with aggregations of phytoplankton and zooplankton, and a variety of other fine-scale surprises.

*Patrick Gray, Duke University Marine Lab, pgrayobx@gmail.com, 0000-0002-8997-5255 

Anna Windle, University of Maryland Center for Environmental Science, awindle@umces.edu, 0000-0002-4852-5848

Ivan Sayvelev, Naval Research Laboratory, ivan.savelyev@nrl.navy.mil 

Julian Dale, Duke University Marine Lab, julian.dale@duke.edu, 0000-0001-6466-3426

Katelyn Smith, Wake Forest University, smitka20@wfu.edu, 0000-0001-6930-6348

Jessica Gronniger, Duke University Marine Lab, jessica.gronniger@duke.edu 

Nicolas Cassar, Duke University, Nicholas School of the Environment, nicolas.cassar@duke.edu, 0000-0003-0100-3783

Marina Lévy, French National Centre for Scientific Research, marina.levy@locean.ipsl.fr, 0000-0003-2961-608X

Emmanuel Boss, University of Maine, emmanuel.boss@maine.edu, 0000-0002-8334-9595

Greg Silsbe, University of Maryland Center for Environmental Science, gsilsbe@umces.edu, 0000-0003-2673-1162

Zackary Johnson, Duke University Marine lab, zackary.johnson@duke.edu, 0000-0003-0793-8512

Dana Hunt, Duke University Marine Lab, dana.hunt@duke.edu, 0000-0002-8801-9624

Sheri Floge, Wake Forest University, floges@wfu.edu, 0000-0002-1996-3347

Guillaume Bourdin, University of Maine, guillaume.bourdin@maine.edu, 0000-0001-7608-5256

David Johnston, Duke University Marine Lab, david.johnston@duke.edu, 0000-0003-2424-036X