Dataset: ETSP NO3 and NO2 isotopes
Deployment: AT15-61

ETSP NO3 and NO2 isotopes

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/903891

Principal Investigator:

Karen L. Casciotti (Woods Hole Oceanographic Institution, WHOI)

Scientist:

Alyson E. Santoro (Woods Hole Oceanographic Institution, WHOI)

Student:

Carolyn Buchwald (Woods Hole Oceanographic Institution, WHOI)

Noah Gluschankoff (Stanford University)

Analyst:

Matthew Forbes (Stanford University)

Matthew R. McIlvin (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

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

Project:

Expression of Microbial Nitrification in the Stable Isotopic Systematics of Oceanic Nitrite and Nitrate (Microbial Nitrification)

Version:

Deployment Synonyms:

ETSP2010

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Description

Nitrous oxide (N2O) data from the samples are available in the related dataset "ETSP N2O" (https://www.bco-dmo.org/dataset/821268).

Methods & Sampling

Dataset acquisition description

Seawater samples were obtained during the R/V Atlantis (AT15-61) and R/V Melville (MV1104) cruises from January to February 2010 and March to April 2011. Water samples were collected at discrete depths using Niskin bottle type rosette samplers equipped with either 24 bottles (10L) or 12 bottles (20L), and an SBE9plus conductivity-temperature-depth (CTD) sensor package (SeaBird Electronics, Bellevue, WA).

The d15N and d18O of NO3- was determined using the "denitrifier" method (Casciotti et al., 2002; Sigman et al., 2001) with updated techniques (McIlvin & Casciotti, 2011). Samples were treated with sulfamic acid to remove NO2-, if present (Granger & Sigman, 2009).

The d15N and d18O of NO2- was determined using the chemical reduction of NO2- to nitrous oxide (N2O) using the "azide method" (McIlvin & Altabet, 2005).

Samples were collected on the R/V Atlantis in January through February 2010, and the R/V Melville in March through April 2011 between 10° and 20° South and between 80° and 100° West, with station locations and sample depths, salinities, sigma theta, oxygen concentrations values, etc. reported in the 'ETSP N2O' dataset. Water column samples were collected by Niskin bottles deployed on a rosette equipped with conductivity-temperature-depth (CTD) sensors. All samples were collected into sample-rinsed HDPE bottles and passed through a 0.2 micrometer (um) filter before collection, and were stored at -20° Celsius until analysis on land.

Data Processing Description

Dataset Processing Description

BCO-DMO Processing:
- Imported original file named "ETSP_ENSO_no3_no2_isotope_BCODMO_230227.xlsx" sheet 1 into the BCO-DMO data system.
- Replaced missing data identifier of 'NaN' with blank/empty values, which is the default for csv files.
- Added columns ISO_DateTime_Local, Latitude, and Longitude from related N2O dataset (https://www.bco-dmo.org/dataset/821268) by joining on key comprised of Year+Station+Depth.
- Named the final file "903891_v1_etsp_no3_and_no2_isotopes.csv".

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0961098	NSF Division of Ocean Sciences

Instruments

CTD - profiler

Supplied Description:

Instrument Type

Generic Name: CTD - profiler

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/130/

Generic Description:

The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast.

This term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934.

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo Delta Plus XP isotope ratio mass spectrometer

Supplied Description:

Used to analyze NO3- and NO2- d15N and d18O.

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 Description:

Used to collect water samples.

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

Supplied Name	Supplied description	Supplied Units	Standard Name
Year	Year sampled	unitless	year
Station	Station	unitless	station
Depth	Sample Depth	meters (m)	depth
del15N_NO3	Delta 15N of nitrate; expressed in permille notation in reference to atmospheric N2	permille	dN15_NO3
del15N_NO3_sd	Delta 15N of nitrate; 1 standard deviation expressed in permille notation in reference to atmospheric N2	permille	dN15_NO3
del18O_NO3	Delta 18O of nitrate; expressed in permille notation in reference to VSMOW (vienna standard mean ocean water)	permille	d18O_NO3
del18O_NO3_sd	Delta 18O of nitrate; 1 standard deviation expressed in permille notation in reference to VSMOW (vienna standard mean ocean water)	permille	d18O_NO3
del15N_NO2	Delta 15N of nitrate expressed in permille notation in reference to atmospheric N2	permille	d15N
del15N_NO2_sd	Delta 15N of nitrite; 1 standard deviation expressed in permille notation in reference to atmospheric N2	permille	d15N
del18O_NO2	Delta 18O of nitrite; 1 standard deviation expressed in permille notation in reference to VSMOW (vienna standard mean ocean water)	permille	d18O
del18O_NO2_sd	Delta 18O of nitrite; 1 standard deviation expressed in permille notation in reference to VSMOW (vienna standard mean ocean water)	permille	d18O
ISO_Date_Local	Date of sampling in ISO 8601 format. Timezone was GMT-5 in 2010, GMT-4 in 2011	unitless	ISO_DateTime_Local
Latitude	Latitude of sample collection, South is negative	decimal degrees	lat
Longitude	Longitude of sample collection, West is negative	decimal degrees	lon

Database

Contribute Data

Dataset: ETSP NO3 and NO2 isotopes
Deployment: AT15-61

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: ETSP NO3 and NO2 isotopesDeployment: AT15-61

Dataset acquisition description

Dataset Processing Description

Dataset: ETSP NO3 and NO2 isotopes
Deployment: AT15-61