Dataset: Subterranean Estuary In Situ Tracer Experiment Incubation Data, 2019

Name: In situ tracer injection experiment conducted with 15N-labeled ammonium in a shallow, sandy subterranean estuary in Gloucester Point, USA in August 2019.
Published: 2024-01-15
Keywords: nitrogen, isotope, nitrification, subterranean estuary, oceans

Cite This Dataset

DOI:10.26008/1912/bco-dmo.917767.1

Spatial Extent: N:37.248884 E:-76.505324 S:37.248884 W:-76.505324

Gloucester Point Beach subterranean estuary (37.248884N, 76.505324W) in Gloucester Point, VA, USA.

Temporal Extent: 2019-08-19 - 2019-08-23

Project:

Collaborative Research: Cryptic nitrogen cycling in the anoxic subterranean estuary (Subsurface cryptic N cycle)

Principal Investigator:

Bongkeun Song (Virginia Institute of Marine Science, VIMS)

Co-Principal Investigator:

Iris C. Anderson (Virginia Institute of Marine Science, VIMS)

Craig Tobias (University of Connecticut, UConn)

Student:

Stephanie J. Wilson (Virginia Institute of Marine Science, VIMS)

Contact:

Stephanie J. Wilson (Virginia Institute of Marine Science, VIMS)

BCO-DMO Data Manager:

Karen Soenen (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

Version Date:

2024-01-15

Restricted:

Validated:

Yes

Current State:

Final no updates expected

In situ tracer injection experiment conducted with 15N-labeled ammonium in a shallow, sandy subterranean estuary in Gloucester Point, USA in August 2019.

Abstract:

These data are the result of an in situ tracer injection experiment conducted with 15N-labeled ammonium to determine the fate and transport rates of ammonium within a shallow, sandy subterranean estuary in Gloucester Point, VA, USA. Replicate injections of 15N-labeled ammonium, sulfur hexaflouride, and bromide amended porewater were injected into piezometers at 50cm. Porewater was then collected overtime from the injection piezometers and tracer piezometers surrounding the injection site ranging in depth from 40-60cm. At each time point, samples were collected to analyze dissolved inorganic nitrogen (nitrate, nitrite, and ammonium) concentrations, sulfur hexaflouride, bromide, chloride. Nitrate and nitrite samples from porewater were analyzed with an isotope ratio mass spectrometer in order to assess the 15N enrichment of the nitrate in each sample resulting in a delta value (d15N) that allows for the calculation of the mole fraction of 15N-labeled nitrite and nitrate in porewater at each time point. The production or consumption over time constitutes subterranean estuary nitrogen cycling rates (e.g. nitrification, denitrification, etc.).

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Archival Copy

Version Date	Archive	Persistent Identifier (PID)	Date PID Issued
2024-01-15	Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)	10.26008/1912/bco-dmo.917767.1	2024-01-15

Methods & Sampling

These data were collected during August 2019 from a sandy subterranean estuary (STE) located in Gloucester Point, Virginia, USA. Porewater was collected from surface water and piezometers placed at 40, 50, and 60cm. Prior to the injection, porewater was collected from replicate 50cm piezometers and amended with 15N-labeled ammonium, sulfur hexaflouride, and bromide. The amended porewater was then reintroduced into the STE through the 50cm injection piezometers.

After injection porewater was collected overtime from both the injection piezometers and other piezometers surrounding the injection well. At each time point, porewater was collected in serum bottles prepared with potassium hydroxide and were equlibrated by shaking before being run on a gas chromatograph with electron capture detection (GC-ECD, Shimadzu) in order to determine the sulfur hexaflouride concentration. Porewater was also collected for inorganic nutrients and ions, filtered with a 0.45 µm syringe filter (Whatman GE) and were frozen (-20 °C) until analysis.

Data Processing Description

Porewater nutrient concentrations were analyzed for NOx (nitrate + nitrite), nitrite, and ammonium with a Lachat autoanalyzer ions were assessed with an ion chromatograph (ThermoFisher Scientific). The isotopic enrichment of nitrate and nitrite products were measured using a gas bench isotope ratio mass spectrometer (IRMS, Delta V Plus, Thermo Fisher Scientific, Waltham, MA) using the bacterial reduction method. A culture of Pseudomonas aureofaciens reduced NOx in collected samples to N2O. The isotopic composition of the N2O was measured with isotope-ratio mass spectrometry (IRMS) (Sigman et al., 2001).

BCO-DMO Processing

* Split longitude and latitude of experiment location in separate columns
* Reworked Date/Time columns

Data Files

File
917767_v1_tracerdata.csv (Comma Separated Values (.csv), 9.50 KB) MD5:3ea25bd79518ba835e3f1547c5044717 Primary data file for dataset ID 917767, version 1

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-1657801

Deployments

None available yet

Instruments

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

Supplied Name: Ion Chromatograph, ThermoFisher Scientific; Lachat QuikChem 8000 automated ion analyzer Lachat In- struments

Supplied Description:

Ion Chromatograph, ThermoFisher Scientific; Lachat QuikChem 8000 automated ion analyzer Lachat In- struments, Milwaukee, WI, USA; detection limits for NO3−, NH4+, and PO43− are 0.20, 0.36, and 0.16 μM, respectively. Gas bench isotope ratio mass spectrometer (IRMS) Delta V Plus, Thermo Fisher Scientific, Waltham, MA.

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
Site_Name	Site name where experiment was conducted	unitless	site
Latitude	Latitude of experiment site location	decimal degrees	lat
Longitude	Longitude of experiment site location	decimal degrees	lon
Piezometer	The ID of the piezometer that was sampled written as replicate cluster-injection site or trace site-depth in cm; (e.g., 1-I-50 is the first replicate cluster, injection site, 50cm depth)	unitless	sample_descrip
Sample_ID	The ID of the piezometer that was sampled written as replicate cluster-injection site or trace site-depth in cm-timepoint; (e.g., 1-I-50-T1 is the first replicate cluster, injection site, 50cm depth, time point 1 )	unitless	sample
Time_Point	Injection experiment time point (BKGD, T0, T1, T2, etc). BKGD means background samples, so samples that were collected prior to the start of the injection.	unitless	time_point
Date	Date of sample collection Format: %Y-%m-%d	unitless	date
Time	Time of sample collection Format: %H:%M	unitless	time
Hours_after_Injection	Hours after injectate was introduced in the subsurface	hours (hrs)	time_inc
Bromide_uM	Bromide concentration in porewater in micromoles per liter (uM) measured by ion chromatograph	micromoles per liter (uM)	bromides
Chloride_mM	Chloride concentration in porewater in millimoles per liter (mM) measured by ion chromatograph	millimoles per liter (mM	chloride
SF6_ppbv	Sulfur hexaflouride concentration in porewater in parts per billion per volume (ppbv) measured by gas chromatograph-electron capture detector	parts per billion per volume (ppbv)	SF6
SF6_pM	Sulfur hexaflouride concentration in porewater in picoMolar (pM) measured by gas chromatograph-electron capture detector	picoMolar (pM)	SF6
Nox_uM	Nitrate + Nitrite concentration in porewater in micromoles per liter (uM) measured by a lachat autoanalyzer	micromoles per liter (uM)	NO3_NO2
NO2_uM	Nitrite concentration in porewater in micromoles per liter (uM) measured by a lachat autoanalyzer	micromoles per liter (uM)	NO2
NH4_uM	Ammonium concentration in porewater in micromoles per liter (uM) measured by a lachat autoanalyzer	micromoles per liter (uM)	NH4
True_d15N	Delta 15N measurement made by an isotope ratio mass spectrometer	parts per thousand (‰)	d15N
Mole_Fraction_Calc	15N Mole Fraction calculated from the d15N value	unitless	d15N