Bottle sample data from CTD casts from the third cruise of SPIROPA project, R/V Thomas G. Thompson cruise TN368, to the New England Shelfbreak in July of 2019 (NCEI Accession 0278016)

This dataset contains biological, chemical, optical, and physical data collected on R/V Thomas G. Thompson during cruise TN368 in the North Atlantic Ocean from 2019-07-08 to 2019-07-16. These data include Ammonium, Carbon, Nitrate, Nitrogen, Oxygen in volts, PAR, Partial pressure of CO2, Silicate, chlorophyll a, conductivity, density, depth, depth nominal, dissolved Oxygen, dissolved inorganic Carbon, fluorescence, irradiance, particulate organic Carbon (POC), particulate organic nitrogen, potential temperature, primary production, reactive phosphorus (PO4), salinity calculated from CTD primary sensors, sigma-t, sound velocity, total alkalinity (TA), total phaeopigment, turbidity, water pressure, and water temperature. The instruments used to collect these data include CTD Sea-Bird SBE 911plus, LI-COR Biospherical PAR Sensor, Photosynthetically Available Radiation Sensor, Pressure Sensor, Sea-Bird SBE 43 Dissolved Oxygen Sensor, Turbidity Meter, and Wet Labs ECO-AFL/FL Fluorometer. These data were collected by Dennis J. McGillicuddy and Weifeng Gordon Zhang of Woods Hole Oceanographic Institution as part of the "Collaborative Research: Shelfbreak Frontal Dynamics: Mechanisms of Upwelling, Net Community Production, and Ecological Implications (SPIROPA)" project. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2021-04-21.

The following is the text of the dataset description provided by BCO-DMO:

Acquisition Description:
Location: New England Shelfbreak 40 S 71W depth 80-2000m.

Standard station CTD profiles measurements (down casts, see dataset https://www.bco-dmo.org/dataset/807119) with water sampling (up casts). This dataset (dataset ID 849340) includes the bottle sample data which is from the up casts.

Twenty-four 10 L Niskin bottles fitted with Teflon-coated external closures were used for water column sampling. At each station, samples were typically collected at 12 discrete depths for assessment of nutrient concentrations. These samples were syringe-filtered and stored at -20°C until analysis at the WHOI Nutrient Analytical Facility. Nitrate and silicate were measured using standard AutoAnalyzer techniques. To measure ammonium concentrations, site water was cartridge-filtered (0.1 µm, Pall Co.) directly from Niskin bottles using a peristaltic pump. Filtrate was collected in FalconTM tubes that were pre-treated with orthophthaldialdehyde (OPA) and measured on-board via the OPA method (Holmes et al., 1999) with a detection limit of 10 nM.

To measure particulate organic carbon and nitrogen, water was collected from the Niskin bottles and filtered through combusted 0.7 µm glass fiber filters (Whatman GF/F), rinsed with a weak acid (0.01 N HCl in seawater) to remove carbonates, then dried in combusted glass vials at 60 °C. Diatom biomass was assessed by sampling for biogenic silica. Samples were filtered through 0.6 µm polycarbonate filters, dried at 60°C in plastic Petri dishes, and dissolved in strong acid.

For incubation-based primary productivity, water samples were taken from Niskin bottles at known isolumes, then placed in sterile 285 mL Qorpak bottles, then ~20 µCi NaH14CO3 was added. An on-deck incubator holding the bottles had surface seawater flowing through it, with irradiance attenuated by neutral density filters to the light levels at the isolumes sampled. Blue filters were used for isolumes below 30% Eo. After 24 h, samples were filtered through GFF filters and placed in 7 mL scintillation vials. Size fractionations were conducted at all stations using 20 µm Poretics filters on subsamples from each bottle. 100 µL 1N HCl was added to volatilize absorbed inorganic 14C. Ecolume (5 mL) was then added to each vial, and all vials were counted after 24 h on a liquid scintillation counter. Total activity was measured by counting 100 μL of non-acidified sample in β-phenethanylamine.