Dissolved inorganic carbon (DIC) from Niskin bottle samples from the PICO time-series station (34.7181 deg N, 76.6707 deg W) from 2010-2012 (PICO project)

Website: https://www.bco-dmo.org/dataset/4031
Version: 30 Aug 2013
Version Date: 2013-08-30

» Pivers Island Coastal Observatory (PICO)
Johnson, Zackary I.Duke UniversityPrincipal Investigator, Contact
Hunt, DanaDuke UniversityCo-Principal Investigator
Rauch, ShannonWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Dataset Description

Dissolved inorganic carbon (DIC; uM Carbon) from the Pivers Island Coastal Observatory (PICO) from 2010 to 2012.

Note: DIC was not measured at all time points, thus, some dates have no data ('nd') in the 'DIC' column.

Methods & Sampling

Water was sampled using a 5 L niskin bottle centered at 1 m with a bottle length of 0.7 m. DIC was measured on mercuric chloride poisoned samples by acidification and subsequent quantification of released CO2 using a CO2 detector (Li-Cor 7000). DIC samples were collected following recommended procedures (Dickson et al., 2007) and measurements were calibrated against Certified Reference Materials provided by Dr. A. G. Dickson at Scripps Institution of Oceanography (SIO), University of California, San Diego (UCSD).

Dickson, A.G., Sabine, C.L., and Christian, J.R. (eds) (2007) Guide to best practices for ocean CO2 measurements: PICES Special Publication 3.

Data Processing Description

Quality Scores (qflag) as follows:
1 = excellent (no known issues),
2 = suspect,
3 = poor (known reason to suspect data).

BCO-DMO Processing Notes:
- Created 'replicate' column and re-arranged data so that replicates are in rows, not columns.
- Modified parameter names to conform with BCO-DMO naming conventions.
- Replaced blanks with 'nd' to indicate 'no data'.
- Separated date into month, day, and year columns.

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Data Files

(Comma Separated Values (.csv), 84.11 KB)
Primary data file for dataset ID 4031

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deploymentDeployment name/id number. text
latLatitude of sampling location. Positive = North. decimal degrees
lonLongitude of sampling location. Positive = East. decimal degrees
yearYear (local time) of the sampling event. YYYY
month_localMonth (local time) when the sampling event occurred. mm (01 to 12)
PID_numUnique, sequential "occupation" number for sampling. (The unique time/day when sampling occurred.) dimensionless
day_localDay of month (local time) when the sampling event occurred. dd (01 to 31)
time_localTime (local) when the sampling event occurred; 24-hour clock. HHMM.mm
time_qflagQuality score for time_local: 1 = excellent (no known issues); 2 = suspect; 3 = poor (known reason to suspect data). dimensionless
depthDepth of water sampling. meters
replicateReplicate identifier. (All of the "A" DIC samples are from the same bottle, however "A" replicates for DIC are unrelated to "A" replicates in the other PICO datasets.) text
DICDissolved inorganic carbon. micromolar Carbon (uM C)
DIC_qflagQuality score for DIC: 1 = excellent (no known issues); 2 = suspect; 3 = poor (known reason to suspect data). dimensionless
yrdayConsecutive day of year for a specified year, as a decimal. The fraction of the value represents the time within the day (e.g. a value of 1.5 means January 1 at 1200 hours). dimensionless
ISO_DateTime_LocalDate-time (local) formatted to ISO 8601 standard. YYYY-MM-DDTHH:MM:SS.ss

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Dataset-specific Instrument Name
LI-COR LI-7000 Gas Analyzer
Generic Instrument Name
LI-COR LI-7000 Gas Analyzer
Dataset-specific Description
DIC was measured on mercuric chloride poisoned samples by acidification and subsequent quantification of released CO2 using a Li-Cor 7000 CO2 detector.
Generic Instrument Description
The LI-7000 CO2/H2O Gas Analyzer is a high performance, dual cell, differential gas analyzer. It was designed to expand on the capabilities of the LI-6262 CO2/ H2O Gas Analyzer. A dichroic beam splitter at the end of the optical path provides radiation to two separate detectors, one filtered to detect radiation absorption of CO2 and the other to detect absorption by H2O. The two separate detectors measure infrared absorption by CO2 and H2O in the same gas stream. The LI-7000 CO2/ H2O Gas Analyzer is a differential analyzer, in which a known concentration (which can be zero) gas is put in the reference cell, and an unknown gas is put in the sample cell.

Dataset-specific Instrument Name
Niskin bottle
Generic Instrument Name
Niskin bottle
Dataset-specific Description
Water was sampled using a 5 Liter niskin bottle.
Generic Instrument 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.

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Duke University Marine Lab
Start Date
End Date
The PICO time series is sampled weekly (or more frequently) to capture physical, chemical and biological variability in the coastal ocean. This time series enables the investigator to collaborate with a number of researchers and will serve as a long-term research focus. Project information: http://oceanography.ml.duke.edu/johnson/research/pico/

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Project Information

Pivers Island Coastal Observatory (PICO)

Coverage: 34.7181 deg N, 76.6707 deg W

From the project website:
Carbon dioxide is rising at ~3% per year in the atmosphere and oceans leading to increases in dissolved inorganic carbon and a reduction in pH. This trend is expected to continue for the foreseeable future and ocean pH is predicted to decrease substantially making the ocean more acidic, potentially affecting the marine ecosystem. However, coastal estuaries are highly dynamic systems that often experience dramatic changes in environmental variables over short periods of times. In this study, the investigators are measuring key variables of the marine carbon system along with other potential forcing variables and characteristics of the ecosystem that may be affected by these pH changes. The goal of this project is to determine the time-scales and magnitude of natural variability that will be superimposed on any long term trends in ocean chemistry.

This project is associated with Ocean Acidification: microbes as sentinels of adaptive responses to multiple stressors: contrasting estuarine and open ocean environments.

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Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
NSF Ocean Sciences Research Initiation Grants (NSF OCE-RIG)

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