Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Program Information
• Funding

Fluxes of lipid biomarkers in the 1500 m and 3200 m Oceanic Flux Program sediment traps in the northern Sargasso Sea, before, during and after of Hurricane Nicole 2016 (Sep-Dec 2016)

Sinking particles were collected at 1500 m and 3200 m depths by Parflux sediment traps (McLane Labs, Falmouth, MA) on the Oceanic Flux Program (OFP) mooring. Trap cups were filled with 40 ppt deep seawater (concentrated by freezing) poisoned with ultra-trace metal purity HgCl2 (200 mg L-1). OFP methods are detailed in Conte et al. (2001, 2018). Sinking particles analyzed in this study were collected between 25 October 2016 and 10 December 2016 with a biweekly sample resolution.

Lipids were preserved and analyzed using a modification of methods in Conte et al. (2003) (Pedrosa-Pàmies et al., 2018). Briefly, an internal standard mixture (n-C21:0 fatty alcohol, n-C23:0 fatty acid, 5α-cholestane and n-C36:0 alkane) was added to the samples prior to lipid extraction. Lipids were ultrasonically extracted in 2:1 CHCl3-MeOH, transesterified with methanolic HCl and trimethylsilylated using BSTFA with 1% TMCS. The transesterified, trimethylsilyl derivatives were analyzed on an Agilent 7890A GC coupled to a 5975C MS. Compounds were identified by mass spectra and quantified from their FID response relative to the internal standard.

Lipid compounds were identified by their mass spectra and were quantified from their FID response relative to the internal standard. The software used were MSD ChemStation (version E.0202.1431) and Chrom Perfect (version 5.5.2).

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- re-formatted date from d-Mon-yy to yyyy-mm-dd

NSF Award Abstract:
This award continues, for another three years, the Ocean Flux Program (OFP) that has been in continuous operation near Bermuda since 1978. The OFP time-series of particle fluxes in the deep Sargasso Sea has produced a unique record of the "biological pump," a term used to describe the sinking of biological material from the surface to the deep ocean. The OFP provided the first direct evidence for seasonal changes in the deep ocean and tight links between deep ocean and upper ocean processes. The OFP provides clear evidence for the intensity of biological activity throughout the ocean's interior and the roles of key processes in biogeochemical and elemental cycling. The time-series is becoming long enough to study flux variability in terms of ocean basin-scale forcing, such as the North Atlantic Oscillation. The OFP sample archives are an unparalleled resource for study of temporal trends and the biogeochemical consequences of changing ocean chemistry. Education provided by the OFP broadens the experiences and science directions of many students (high school to PhD levels) and early investigators at critical career junctures.

The OFP time-series is the longest of its kind and unique in its focus on the deep ocean. As the record lengthens, investigators are better able to put into perspective the observed flux patterns in terms of the interplay between climate and ocean functioning. Colocation of complementary time-series -- Hydrostation S, the Bermuda Atlantic Time-Series (BATS), the Bermuda Testbed Mooring (BTM, 1994-2007), the Tudor Hill atmospheric tower and other sampling conducted near the Bermuda Time-Series Site -- and continuing advances in instrumentation on the OFP mooring present unparalleled opportunities to study coupling among ocean physics, biology and chemistry and material fluxes, and flux linkages with atmospheric and climatic forcing. As ever more sophisticated analytical tools are used to probe the recovered flux materials, new data continue to reveal novel information about ocean processes.

(Adapted from the NSF Project Summary)

Since 1978, the Oceanic Flux Program (OFP), originally founded and managed by at the Woods Hole Oceanographic Institution and now managed by the Bermuda Institute of Ocean Science (BIOS), has continuously measured particle fluxes in the deep Sargasso Sea. The 35+ year OFP time-series is, by far, the longest of its kind and unique in its focus on the deep ocean. OFP has produced a unique, albeit "edited", record of temporal variability in the "biological pump", a term loosely applied here to material transfer from the surface to the deep ocean. The OFP provided the first direct evidence for seasonality in the deep ocean and the tight coupling between deep fluxes and upper ocean processes. It has provided clear evidence of the intensity of biological reprocessing of flux and scavenging of suspended material in mesopelagic waters. The record has documented interannual and longer variations in deep fluxes and shorter term fluctuations driven by the interactions between mesoscale physical variability, meteorological forcing and ecosystem responses.