Dataset: Dissolved trace metals and macronutrients from a 2014 IRNBRU cruise Surface Data

Name: Dissolved trace metals and macronutrients from samples collected using a tow-fish system on R/V Melville MV1405 (IRN-BRU) cruise in the California Current System in July 2014
Published: 2024-11-20
Keywords: California Current System, coastal upwelling, cyclonic eddies, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.943015.1

Spatial Extent: N:42.8684 E:-123.5954 S:37.6695 W:-127.1993

The California Current System, 33-44N, 118-128W, surface to 1500m max

Temporal Extent: 2014-07-06 - 2014-07-24

Project:

Accomplishment Based Renewal: An iron limitation mosaic within the central California Current System (iron limitation mosaic)

Principal Investigator:

Kenneth W. Bruland (University of California-Santa Cruz, UCSC)

Scientist:

Tyler Coale (University of California-Santa Cruz, UCSC)

Student:

Claire P. Till (University of California-Santa Cruz, UCSC)

BCO-DMO Data Manager:

Audrey Mickle (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-11-20

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Dissolved trace metals and macronutrients from samples collected using a tow-fish system on R/V Melville MV1405 (IRN-BRU) cruise in the California Current System in July 2014

Abstract:

This dataset is a suite of dissolved trace metal concentrations, along with macronutrient concentrations collected using a trace-metal clean towed-fish system on R/V Melville cruise MV1405 (IRN-BRU) while investigating the mosaic of the California Current System in July 2014. This dataset includes samples from transects 2, 5, 8, and 9. Transect 2 started at station 2 (an active upwelling site nearshore over the shelf in northern California; see related datasets) and followed the upwelled plume offshore. Transect 5 went through the eddy stations (stations 9, 12, and 15; see related datasets). Transects 8 and 9 went through the plume measured in station 28 (a more aged upwelling site offshore of the shelf break in southern Oregon; see related datasets). The chief scientist of the cruise was Ken Bruland. Trace metal samples were analyzed by Claire Till (nee Parker) as his graduate student. Nutrient samples were analyzed by Tyler Coale. See related datasets for depth profile samples using a regular rosette (macronutrient concentrations) and teflon-coated GoFlos (macronutrient and dissolved trace metal concentrations) collected on MV1405.

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2024-11-20	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.943015.1	2024-11-25

Methods & Sampling

Nitrate-nitrite, Phosphate, Silicate, Nitrite

Samples were collected from a trace-metal clean towed-fish system (Bruland et al., 2001). Samples were analyzed shortly after collection at sea using standard spectrophotometric methods (Parsons 1984) on a Lachat QuickChem 8000 Flow Injection Analysis System.

Dissolved trace metals

Surface samples for transects were sampled using a tow-fish system (Bruland et al., 2001) plumbed into a trace metal clean van. Samples were filtered directly from the GoFlo through 0.2 μm Acropak Supor membrane capsule filters into pre-cleaned LDPE bottles. The acropaks were pre-cleaned and flushed with at least 250 mL of sample before sampling. Sample bottles were pre-cleaned cleaned rigorously as per the GEOTRACES cookbook (Cutter et al., 2014), and were rinsed with sample three times before filling. Samples were acidified at sea to a pH of ~1.7 with quartz-distilled 6 M HCl (4 mL per liter) and stored for analysis post-cruise. Samples were analyzed for trace metals after the cruise with the method of Biller and Bruland (2012), with modifications as described in Parker et al. (2016). Briefly, this involves buffering the seawater to pH 6.0 ± 0.2 immediately before pre-concentrating on PA1 resin. The resin was extracted with 1 N optima nitric acid with rhodium as an internal standard. Extracts were analyzed on the Thermo Fisher Element 2 extended range ICP-MS at UC Santa Cruz.

Iron was additionally analyzed shipboard with a flow injection analysis method published in Lohan et al. (2006) with modifications as described in Biller et al. (2013). Briefly, this method involves pre-concentrating the iron on a toyopearl column at pH 2, eluting it into a buffered (pH ~5.7) reaction stream that contains DPD, a molecule that turns pink when oxidized by iron. H2O2 is also in the reaction stream, which re-oxidizes the iron, so that each iron molecule can react with multiple DPD molecules, another mechanism to increase the iron signal. The reaction stream absorbance is measured with a flow through spectrophotometer.

Generally, the measurements from these two methods for Fe agreed well; where there was a problem with one or the other dataset, we only report one dataset.

Data Processing Description

For the surface transect data, we did not have nutrient data and trace metal data taken from exactly the same moment. In order to directly compare the two datasets, the nutrient data was interpolated based on time to align with the trace metal data.

BCO-DMO Processing

- Imported original file "IRNBRU TM and macronutrient surface data.xlsx" into the BCO-DMO system.
- Converted "DATE TIME (GMT)" from %Y-%m-%dT%H:%M:%S to ISO format %Y-%m-%dT%H:%M:%SZ and changed parameter name to "ISO_DateTime_UTC"
- Renamed fields to comply with BCO-DMO naming conventions, removing special characters and spaces
- Saved the final file as "943015_v1_iron_limitation_surface.csv"

Data Files

File
943015_v1_iron_limitation_surface.csv (Comma Separated Values (.csv), 9.04 KB) MD5:65549e04f75cdea5bb26dbb32e112f14 Primary data file for dataset ID 943015, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1259776

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
MV1405	IrnBru IronBru	2014-07-03	R/V Melville	Kenneth W. Bruland (Chief Scientist)	data info

Instruments

GeoFish Towed near-Surface Sampler

Supplied Name: trace-metal clean towed-fish system

Supplied Description:

Samples were collected from a trace-metal clean towed-fish system (Bruland et al., 2001) (transects), from teflon-coated Go-Flos on a non-metal line, and from the ship's rosette. Samples were analyzed shortly after collection at sea using standard spectrophotometric methods (Parsons 1984) on a Lachat QuickChem 8000 Flow Injection Analysis System.

Instrument Type

Generic Name: GeoFish Towed near-Surface Sampler

Acronym: GeoFish

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/31/

Generic Description:

The GeoFish towed sampler is a custom designed near surface (<2m) sampling system for the collection of trace metal clean seawater. It consists of a PVC encapsulated lead weighted torpedo and separate PVC depressor vane supporting the intake utilizing all PFA Teflon tubing connected to a deck mounted, air-driven, PFA Teflon dual-diaphragm pump which provides trace-metal clean seawater at up to 3.7L/min. The GeoFish is towed at up to 13kts off to the side of the vessel outside of the ship's wake to avoid possible contamination from the ship's hull. It was developed by Geoffrey Smith and Ken Bruland (University of California, Santa Cruz).

Inductively Coupled Plasma Mass Spectrometer

Supplied Name: Thermo Element XR magnetic sector inductively coupled plasma mass spectrometer (ICP-MS)

Supplied Description:

Trace metal extracts were analyzed with a Thermo Element XR magnetic sector inductively coupled plasma mass spectrometer (ICP-MS)

Instrument Type

Generic Name: Inductively Coupled Plasma Mass Spectrometer

Acronym: ICP Mass Spec

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/

Generic Description:

An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer.

Lachat QuikChem 8000 flow injection analyzer and Ion Chromatography (IC) system

Supplied Name: Lachat QuickChem 8000 Flow Injection Analysis System

Supplied Description:

Nutrients were analyzed with a Lachat QuickChem 8000 Flow Injection Analysis System.

Instrument Type

Generic Name: Lachat QuikChem 8000 flow injection analyzer and Ion Chromatography (IC) system

Generic Description:

The Lachat QuikChem 8000 can operate flow injection analysis and ion chromatography simultaneously and independently on the same instrument platform. Instrument includes sampler, dilutor, sampling pump, electronics unit, and data station. Analysis takes 20-60 seconds, with a sample throughput of 60-120 samples per hour. Measurements are in the range of parts per trillion to parts per hundred.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
DATE_TIME_ISO_UTC	Date and time of sample collection in UTC Format: %Y-%m-%dT%H:%M:%SZ	unitless	ISO_DateTime_UTC
Latitude	Latitude of sampling site, negative values = South	unitless	lat
Longitude	Longitude of sampling site, negative values = West	unitless	lon
Transect_number	Transect identification	unitless	site
Nitrate	Nitrate concentration	umol/kg	NO3_NO2
Phosphate	Phosphate concentration	umol/kg	PO4
Silicate	Silicic concentration	umol/kg	Silicate
Fe	Iron concentration	nmol/kg	Fe
Y	Yttrium concentration	pmol/kg	trace_metal_conc
Cd	Cadmium concentration	pmol/kg	Cd
La	Lanthanum concentration	pmol/kg	Lanthanum
Pb	Lead concentration	pmol/kg	Pb
Ce	Cerium concentration	pmol/kg	trace_metal_conc
Sc	Scandium concentration	pmol/kg	Sc
Mn	Manganese concentration	nmol/kg	Mn
Co	Cobalt concentration	pmol/kg	Co
Ni	Nickel concentration	nmol/kg	Ni
Cu	Copper concentration	nmol/kg	Cu
Zn	Zinc concentration	nmol/kg	Zn
Ga	Gallium concentration	pmol/kg	Ga

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Dataset: Dissolved trace metals and macronutrients from a 2014 IRNBRU cruise Surface Data