Carbon export and fate beneath a dynamic upwelled filament off the California coast

Abstract. To understand the vertical variations in carbon fluxes biologically productive waters, four autonomous flux explorers (CFEs), ship-lowered CTD-interfaced particle-sensitive transmissometer and scattering sensors, surface-drogued sediment traps were deployed a filament of offshore flowing, recently upwelled water, during June 2017 California Current Ecosystem – Long Term Ecological Research process study. The Lagrangian CFEs operating at depths from 100–500 m yielded its partitioning with size 30 µm–1 cm three intensive study locations within waters outside filament. Size analysis codes intended to enable long-term CFE operations independent ships are described. Different particle classes (anchovy pellets, copepod > 1000 µm aggregates) dominated 100–150 successive stages evolution as it progressed offshore. Fluxes very high all filament; below 150 m, was invariant or increased depth two closer coast. Martin curve b factors (± denotes 95 % confidence intervals) for total particulate +0.37 ± 0.59, +0.85 0.31, ?0.24 0.68, ?0.45 0.70 successively occupied plume, transitional waters. Interestingly, profiles particles < 400 much fit canonical profile (b?0.86); however, most (typically 90 %) carried by sized aggregates which depth. Mechanisms explain factor 3 increase between 500 mid-plume location investigated.