Dataset: Water Column Nitrate d15N Cocos Ridge Upper 1000m

Name: Average nitrate d15N values from the upper 1000 meters of the water column at four stations sampled in the Eastern Tropical North Pacific on R/V Sally Ride cruise SR2113 in December 2021
Published: 2024-09-13
Keywords: isotopes, denitrification, equatorial Pacific, oxygen deficient zones, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.933292.1

Spatial Extent: N:6.7849 E:-86.696 S:5.9596 W:-88.261

Cocos Ridge, Eastern Equatorial Pacific

Temporal Extent: 2021-12-02 - 2021-12-14

Project:

Collaborative Research: New approaches to study calcium carbonate dissolution on the sea floor and its impact on paleo-proxy interpretations (CDISP 2021)

Principal Investigator:

Xingchen Wang (Boston College, BC)

Student:

Kameko Landry (Boston College, BC)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-09-13

Restricted:

Validated:

Yes

Current State:

Final no updates expected

Average nitrate d15N values from the upper 1000 meters of the water column at four stations sampled in the Eastern Tropical North Pacific on R/V Sally Ride cruise SR2113 in December 2021

Abstract:

We report nitrate isotope data at four stations (CR01, CR02, CR03, and CR05) in the Eastern Tropical North Pacific (ETNP). The cruise (R/V Sally Ride SR2113) occupied these four stations near the Cocos Ridge between 6.8 to 5.3 degrees North latitude and 86.6 to 88.26 degrees West longitude. Sampling occurred between December 2-14, 2021. A 24-bottle Niskin rosette and CTD were used to collect 30-milliliter (mL) water samples that were later analyzed using the denitrifier method. The data were collected by Kameko Landry in the Stable Isotope Biogeochemistry Laboratory at Boston College.

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2024-09-13	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.933292.1	2024-09-13

Description

Data were collected on the NSF-funded 2021 "CDISP" cruise on R/V Sally Ride (SR2113). Analyses of the samples presented in this dataset were funded through Boston College.

Methods & Sampling

Water samples were collected directly from the CTD Niskin bottles and filtered through 0.2-micrometer (um) PVDF syringe filters. Samples were collected from approximately 24 depths throughout the water column ranging from 7 to 2900 meters (m), with the shallowest depths being sampled first to avoid nitrate contamination from deeper, higher nitrate samples. The samples were collected in pre-cleaned acid-washed 30-milliliter (mL) HDPE bottles. The bottles and caps were rinsed three times with the sample water. The syringe was rinsed three times before attaching the PVDF syringe filter and, once attached to the syringe, 10 mL of sample water was used to rinse the filter before filling the sample bottles. Once filled, sample bottles were labeled and parafilmed. Samples were immediately frozen on the ship and continued to be frozen until analysis.

Nitrate/nitrite in seawater were quantitatively converted into nitrous oxide using the denitrifier method (Sigman et al., 2001; Weigand et al., 2016). The isotopic composition of the resulting nitrous oxide was analyzed on a custom gas bench system coupled to a Delta V Plus isotope ratio mass spectrometer.

Problems/Issues

Did not collect water samples at CR04.

Data Processing Description

The data are processed and corrected using nitrate isotope standards IAEA NO3 and USGS34.

BCO-DMO Processing

- Imported original file "CCR_BCODMO_FINAL.xlsx" into the BCO-DMO system.
- Marked "nd" as a missing data value (missing data are empty/blank in the final CSV file).
- Converted the date column to YYYY-MM-DD format.
- Renamed fields to comply with BCO-DMO naming conventions.
- Saved the final file as "933292_v1_water_column_nitrate_d15n_cocos_ridge.csv".

Data Files

File
933292_v1_water_column_nitrate_d15n_cocos_ridge.csv (Comma Separated Values (.csv), 2.77 KB) MD5:e6f6881f4212ba717cff880a8ad630e3 Primary data file for dataset ID 933292, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
Boston College	BC internal award

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
SR2113	CDISP	2021-11-20	R/V Sally Ride	Jess F. Adkins (Co-Chief Scientist) William M. Berelson (Co-Chief Scientist)	data info

Instruments

Isotope-ratio Mass Spectrometer

Supplied Name: Delta V Plus isotope ratio mass spectrometer

Supplied Description:

The isotopic composition of the resulting nitrous oxide was analyzed on a custom gas bench system coupled to a Delta V Plus isotope ratio mass spectrometer.

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic Description:

The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

Niskin bottle

Supplied Name: 24-bottle Niskin CTD rosette

Supplied Description:

Instrument Type

Generic Name: Niskin bottle

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0412/

Generic Description:

A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
Station_ID	Cocos Ridge station number + cast number + Niskin bottle number	unitless	sample
Depth_m	Sample depth	meters (m)	depth
WC_NO3	Nitrate concentration	micromoles per kilogram (umol/kg)	NO3
WC_d15N	Averaged d15N in permille vs air. Blank/empty values in this column mean water was not collected from this specific bottle.	permille vs air	d15N
WC_d15N_1sd	Standard deviation of measurements for samples analyzed with more than one run	permille vs air	d15N
Latitude	Latitude of sample collection	decimal degrees	lon
Longitude	Longitude of sample collection; negative values = West	decimal degrees	lon
Date	Date of sample collection Format: %Y-%m-%d	unitless	date

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Database

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Dataset: Water Column Nitrate d15N Cocos Ridge Upper 1000m