Dataset: GP15 Nitrate d15N and d18O Leg 2
Deployment: RR1815

GP15 Nitrate d15N and d18O Leg 2

View Data: For data, See Dataset Metadata Page: https://www.bco-dmo.org/dataset/928099

Principal Investigator:

Daniel M. Sigman (Princeton University)

Co-Principal Investigator:

Karen L. Casciotti (Stanford University)

Scientist:

Jen Karolewski (Stanford University)

Rian Lawrence (Stanford University)

Dario Marconi (Princeton University)

Alfredo Martinez Garcia (Max Planck Institute for Chemistry)

Wentao Wang (Princeton University)

Technician:

Sergey Oleynik (Princeton University)

BCO-DMO Data Manager:

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

Project:

Collaborative Research: US GEOTRACES PMT: Investigating geochemical tracers of the Pacific nitrogen cycle and budget (PMT Nitrate)

US GEOTRACES Pacific Meridional Transect (GP15) (U.S. GEOTRACES PMT)

Version:

Deployment Synonyms:

GP15, GP15 Leg 2, 33RR20180918, PMT, US GEOTRACES PMT

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Description

Methods & Sampling

Dataset acquisition description

Seawater samples were collected using a 36-bottle ODF (Ocean Data Facility) conventional rosette equipped with 10.4-liter (L) Niskin bottles.

HDPE nalgene bottles were acid washed (10% HCl) and rinsed three times (3X) with high-purity water (HPW) before being shipped at sea. Sampling at sea followed the GEOTRACES cookbook indications for nitrate isotopes. Bottles and caps were rinsed three times (3X) with seawater samples from the Niskin before being filled up to shoulder. Samples were then stored kept upright and frozen at -20 degrees Celsius (°C).

Seawater samples were processed in accordance with the published Denitrifier Method (Casciotti et al., 2002). All isotope analyses were performed on a MAT253 Thermo IRMS equipped with a custom-sample preparation system. With this system, we were able to achieve an overall standard deviation of 0.04 per mil for d15N-NO3 analyses and 0.11 per mil for d18O-NO3 analyses. Individual data points have been averaged with standard deviations reported. Please see the papers cited under Related Publications for equations applied to derive final data.

Data Processing Description

Dataset Processing Description

Raw data (for mass 45/44 and 46/44) are generated by the MAT253 Thermo IRMS and are calibrated into nitrate d15N and d18O using a correction scheme developed in Excel.

Quality Flags:
All data are of good quality and have thus been assigned a flag of '1'.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-1736652	NSF Division of Ocean Sciences

Instruments

Isotope-ratio Mass Spectrometer

Supplied Name: MAT253 Thermo IRMS equipped with a custom-sample preparation system

Supplied Description:

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: 10.4L Niskin bottles deployed on the ODF 36-bottle 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

Supplied Name	Supplied description	Supplied Units	Standard Name
Station_ID	Station number	unitless	station
Event_ID	GEOTRACES event number	unitless	event
Start_Date_UTC	Date of sampling (start)	unitless	date
Start_Time_UTC	Time of sampling (start) (UTC)	unitless	time
Start_ISO_DateTime_UTC	Date and time of sampling in ISO 8601 format (start) (UTC)	unitless	ISO_DateTime_UTC
End_Date_UTC	Date of sampling (end)	unitless	date
End_Time_UTC	Time of sampling (end) (UTC)	unitless	time
End_ISO_DateTime_UTC	Date and time of sampling in ISO 8601 format (end) (UTC)	unitless	ISO_DateTime_UTC
Start_Latitude	Latitude of sampling (start); positive values = North	decimal degrees	lat
Start_Longitude	Longitude of sampling (start); negative values = West	decimal degrees	lon
End_Latitude	Latitude of sampling (end); positive values = North	decimal degrees	lat
End_Longitude	Longitude of sampling (end); negative values = West	decimal degrees	lon
Sample_ID	GEOTRACES sample ID	unitless	sample
Sample_Depth	Depth in meters (calculated from pressure and latitude)	meters (m)	depth
NITRATE_15_14_D_DELTA_BOTTLE_w2kmnp	Nitrate d15N in per mil versus air	per mil versus air	dN15_NO3
SD1_NITRATE_15_14_D_DELTA_BOTTLE_w2kmnp	Standard deviation of NITRATE_15_14_D_DELTA_BOTTLE_w2kmnp	per mil versus air	dN15_NO3
Flag_NITRATE_15_14_D_DELTA_BOTTLE_w2kmnp	Quality flag for NITRATE_15_14_D_DELTA_BOTTLE_w2kmnp	unitless	q_flag
NITRATE_18_16_D_DELTA_BOTTLE_dksgvb	Nitrate d18O in per mil versus VSMOW	per mil versus VSMOW	d18O_NO3
SD1_NITRATE_18_16_D_DELTA_BOTTLE_dksgvb	Standard deviation of NITRATE_18_16_D_DELTA_BOTTLE_dksgvb	per mil versus VSMOW	d18O_NO3
Flag_NITRATE_18_16_D_DELTA_BOTTLE_dksgvb	Quality flag for NITRATE_18_16_D_DELTA_BOTTLE_dksgvb	unitless	q_flag
Comment	Indicates for which samples we performed nitrite removal	unitless	comment

Database

Contribute Data

Dataset: GP15 Nitrate d15N and d18O Leg 2
Deployment: RR1815

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: GP15 Nitrate d15N and d18O Leg 2Deployment: RR1815

Dataset acquisition description

Dataset Processing Description

Dataset: GP15 Nitrate d15N and d18O Leg 2
Deployment: RR1815