Depth profile data from R/V New Horizons NH1418 in the tropical Pacific from Sept-Oct. 2014 (NCEI Accession 0278177)

This dataset contains biological, chemical, optical, physical, and survey - biological data collected on R/V New Horizon during cruise NH1418 in the North Pacific Ocean and South Pacific Ocean from 2014-09-20 to 2014-10-06. These data include Nitrate, PAR, chlorophyll a, density, depth, dissolved Oxygen, fluorescence, nitrate plus nitrite, particulate organic Carbon (POC), particulate organic nitrogen, prochlorococcus abundance, salinity calculated from CTD primary sensors, and water temperature. The instruments used to collect these data include Automated Cell Counter, CHN Elemental Analyzer, CTD Sea-Bird SBE 911plus, Flow Cytometer, Niskin bottle, Turner Designs Fluorometer 10-AU, and WETLabs ECO-FLNTU. These data were collected by Michael W. Lomas of Bigelow Laboratory for Ocean Sciences and Adam Martiny of University of California-Irvine as part of the "Biological Controls on the Ocean C:N:P ratios (Biological C:N:P ratios)" project and "Dimensions of Biodiversity (Dimensions of Biodiversity)" and "Ocean Carbon and Biogeochemistry (OCB)" programs. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) submitted these data to NCEI on 2020-11-20.

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

NH1418 ctd

Dataset Description:
Acquisition Description:
Temperature, salinity, oxygen concentration and saturation, and PAR were measured using a Sea-Bird SBE-911+ CTD platform equipped on the rosette deployment system. Fluorescence was measured via the rosette system using a WetLabs ECO AFL/FL platform.

Samples for NO3-/NO2- and NO2- were gravity filtered through 0.8 µm Nucleopore polycarbonate filters using acid cleaned in-line polycarbonate filter holders, then frozen (-20oC) in HDPE bottles until analysis on an Alpkem Flow Solution IV (Dore et al. 1996).

Soluble reactive phosphorus was measured after preparation via the magnesium-induced coprecipitation method (Karl and Tien 1992; Lomas et al. 2010).

Particulate organic carbon (POC), nitrogen (PON), and phosphorus samples were filtered on precombusted Whatman GF/F filters and frozen until analysis. After thawing, POC/PON filters were allowed to dry overnight at 65◦C before being packed into a 30 mm tin capsule (CE Elantech, Lakewood, New Jersey). Samples were then analyzed for C and N content on a FlashEA 1112 nitrogen and carbon analyzer (Thermo Scientific, Waltham, Massachusetts). POC and PON concentrations were calibrated using known quantities of atropine. Particulate organic phosphorus samples (POP) are analyzed using a ash-hydrolysis method (Lomas et al., 2010)

For chlorophyll, ~ 250–500 mL seawater was filtered onto 25-mm Ahlstrom glass fiber filters (nominal pore size 0.7 μm) under low pressure (15 kpa), and frozen immediately at −80_C. Samples were extracted in 90% acetone in the dark for 14–18 h at −20_C and quantified on a Turner 10-AU fluorometer using the acidification method (Parsons et al. 1984).

For cell counts, samples of whole seawater were collected in 2-mL centrifuge tubes, fixed with freshly made 0.2 -μm-filtered paraformaldehyde (0.5% v/v final concentration) for 1 h at 5_C in the dark, and counted on a FACSJazz or Influx flow cytometer (BD, Franklin Lakes, NJ, U.S.A.) utilizing a 200 mW 488 nm laser, with detectors for forward scatter, side scatter, 530 nm, and 692 nm. Prochlorococcus populations were discriminated based on forward scatter and red fluorescence, and a gate in orange (585 nm) discriminated for Synechococcus. Picoeukaryotic phytoplankton were all the red auto fluorescing cells that did not fit the Cyanobacteria gating scheme with a cell size below 2 – 3 μm.

See https://www.rvdata.us/search/cruise/NH1418 for further details.

For published methodologies please see the Related Publications section.