Partial pressure and fugacity of carbon dioxide (pCO2/fCO2), temperature, salinity and other variables collected from surface underway observations using shower head equilibrator, carbon dioxide gas detector and other instruments during R/V Melville cruises MV1305 (EXPOCODE 318M20130321) and MV1306 (EXPOCODE 318M20130508) along the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) Section P02 in the North Pacific Ocean from 2013-03-21 to 2013-06-01 (NCEI Accession 0200367)
PACKAGE DESCRIPTION: This dataset contains underway measurements of partial pressure and fugacity of carbon dioxide (pCO2/fCO2), sea surface salinity, sea surface temperature, and other parameters collected during R/V Melville cruises MV1305 (EXPOCODE 318M20130321) and MV1306 (EXPOCODE 318M20130508) along the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) Section P02 in the North Pacific Ocean from 2013-03-21 to 2013-06-01. The cruises started in Yokohama, Japan and ended in San Diego, CA. This effort was conducted in support of the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) and NOAA's Climate Program Office (CPO).
CITE AS: Cosca, Catherine E.; Alin, Simone R.; Feely, Richard A.; Lebon, Geoffrey T. (2019). Partial pressure and fugacity of carbon dioxide (pCO2/fCO2), temperature, salinity and other variables collected from surface underway observations using shower head equilibrator, carbon dioxide gas detector and other instruments during R/V Melville cruises MV1305 (EXPOCODE 318M20130321) and MV1306 (EXPOCODE 318M20130508) along the Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) Section P02 in the North Pacific Ocean from 2013-03-21 to 2013-06-01 (NCEI Accession 0200367). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/w1t4-g438. Accessed [date].
Surface underway;
TEMPORAL COVERAGE:
SPATIAL COVERAGE:
GEOGRAPHIC NAMES:
PLATFORMS:
RESEARCH PROJECT(S):
VARIABLES / PARAMETERS:
pCO2 (fCO2) autonomous | |
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Abbreviation: | fCO2W@SST_uATM, pCO2W@SST_uATM |
Unit: | uatm |
Observation type: | Surface underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Calculation method and parameters: | Fugacity of CO2 is obtained by correcting the partial pressure of CO2 (pCO2) for non-ideality of the gas with respect to molecular interactions between CO2 and other gases in air. See Pierrot et al. for details on how the correction is made. |
Sampling instrument: | Seawater pump |
Location of seawater intake: | Bow |
Analyzing instrument: | General Oceanics 8050. PMEL system ID: GO12 |
Detailed sampling and analyzing information: | The sampling and analyzing methods of the Neill/General Oceanics Underway pCO2 systems are described in detail in: Pierrot, D., C. Neill, K. Sullivan, R. Castle, R. Wanninkhof, H. Lüger, T. Johannessen, A. Olsen, R.A. Feely, and C.E. Cosca (2009): Recommendations for autonomous underway pCO2 measuring systems and data-reduction routines. Deep-Sea Res. II, 56(8-10), 512-522, https://doi.org/10.1016/j.dsr2.2008.12.005. |
Equilibrator type: | Shower head |
Equilibrator volume: | ~0.5 L |
Is the equilibrator vented or not: | Vented |
Water flow rate: | 3 L/min |
Gas flow rate: | ~0.8 L/m |
How was temperature inside the equilibrator measured: | Hart Scientific model 1521 digital thermometer, serial number 132061, with an NIST traceable model 5610 thermistor probe, serial number B180905. Accurate to ± 0.01°C. |
How was pressure inside the equilibrator measured: | Setra 239 differential pressure transducer, accurate to ± 0.15 hPa. The equilibrator was passively vented to a secondary equilibrator, and the Licor sample output was vented to the laboratory when CO2 measurements were made, thus equilibrator headspace pressure was assumed to be laboratory pressure. |
Drying method for gas: | From Pierrot et al.: Sample air is dried in a condenser that is cooled to 4-5 oC by a Peltier thermoelectric device. This partially dried air flushes a chamber that is vented and remains at ambient pressure. The dried air inside the chamber is used as the counter flow in the Nafion® tubing. A vacuum pump pulls the dried air from the chamber first through a fixed restrictor and then through the Nafion® tubes, thus creating an absolute pressure and corresponding partial pressure gradient for water vapor across the membrane. When atmospheric air is measured, some of the partially dried air (80- 100 ml/min) is pushed through a Nafion® tube, the analyzer and out a vent instead of flushing the chamber. The headspace gas, when being measured, is circulated in a closed loop through the analyzer at a rate similar to that of the atmospheric air (80-100 ml/min). It is dried first in the condenser, then in a Nafion® tube prior to entering the analyzer and being returned to the equilibrator. Typically, the water mole fraction (xH2O) in the dried gas is about 2 parts per thousand (ppt), which corresponds to a dew point temperature of about -20 °C. The liquid water condensed out of the sample air streams is removed by peristaltic pumps into the vent equilibrator at intervals determined by the user. |
SEA CO2 gas detector manufacturer: | Licor, Inc |
SEA CO2 gas detector model: | Licor 7000, IRG4-1045 |
SEA CO2 gas detector resolution: | 0.2 uatm |
SEA CO2 gas detector uncertainty: | 0.3 uatm for equilibrator measurements |
ATM CO2 gas detector manufacturer: | Licor, Inc |
ATM CO2 gas detector model: | IRG4-0560 |
ATM CO2 gas detector resolution: | 0.2 µatm |
ATM CO2 gas detector uncertainty: | 0.3 µatm for equilibrator measurements, 0.2 µatm for atmospheric measurements |
Standardization technique: | The system runs a full cycle in approximately 6 hours. The cycle starts with 4 standard gases, then measures two rounds of 6 atmopherice samples followed by 50 surface water samples. Each new gas is flushed through the Licor Analyzer for 3 minutes prior to a stop-flow measurement. |
Standardization frequency: | Every 6 hours |
Standard gas manufacturer: | Standard gases are supplied by NOAA’s Earth System Research Laboratory, Global Monitoring Division, in Boulder, CO, and are directly traceable to the WMO scale. |
Standard gas concentration: | LL70570, 248.49 ppm; LL81353, 347.20 ppm; LL55878, 405.96 ppm; LL108056, 506.20 ppm |
Standard gas uncertainty: | 0.01 ppm |
Water vapor correction method: | Details of the data reduction are described in Pierrot, et.al. (2009). |
Temperature correction method: | Details of the data reduction are described in Pierrot, et.al. (2009). |
At what temperature was pCO2 reported: | In situ sea surface temperature |
Quality flag convention: | WOCE quality control flags are used: 2 = good value, 3 = questionable value, 4 = bad value |
Method reference: | Pierrot, D., Neill, C., Sullivan, K., Castle, R., Wanninkhof, R., Lüger, H., Johannessen, T., Olsen, A., Feely, R. A., & Cosca, C. E. (2009). Recommendations for autonomous underway pCO2 measuring systems and data-reduction routines. Deep Sea Research Part II: Topical Studies in Oceanography, 56(8-10), 512-522. https://doi.org/10.1016/j.dsr2.2008.12.005 |
Researcher name: | Catherine E. Cosca |
Researcher institution: | Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration |
Sea Surface Temperature | |
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Abbreviation: | SST(TSG)_C |
Unit: | Degree Celcius |
Observation type: | Surface Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Sampling instrument: | Seabird 45, maintained and calibrated yearly by ship personnel |
Uncertainty: | 0.0025 degrees Celsius |
Salinity | |
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Abbreviation: | SAL(TSG)_PERMIL |
Unit: | permil |
Observation type: | Surface Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Sampling instrument: | Seabird 45, serial number 4539646-0143 |
Uncertainty: | 0.005 |
Mole fraction of CO2 in the equilibrator headspace (dry) at equilibrator temperature | |
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Abbreviation: | xCO2W_ppm |
Unit: | ppm |
Observation type: | Surface Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Sampling instrument: | Licor 7000, IRG4-1045 |
Uncertainty: | 0.3 ppm |
Method reference: | See Pierrot et al. for details. |
Mole fraction of CO2 measured in dry outside air | |
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Abbreviation: | xCO2A_ppm |
Unit: | ppm |
Observation type: | Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Sampling instrument: | Licor 7000, IRG4-1045 |
Uncertainty: | 0.2 ppm |
Method reference: | See Pierrot et al. for details. |
Mole fraction of CO2 measured in dry outside air associated with each water analysis. | |
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Abbreviation: | xCO2A_interpolated_ppm |
Unit: | ppm |
Observation type: | Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Calculation method and parameters: | Values are interpolated between measurements of xCO2A_ppm |
Sampling instrument: | Licor 7000, IRG4-1045 |
Uncertainty: | 0.2 ppm |
Method reference: | See Pierrot et al. for details. |
Partial pressure and fugacity of CO2 in air corresponding to the interpolated xCO2 (xCO2A_interpolated_ppm) at SST and 100% humidity | |
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Abbreviation: | pCO2A_uatm, fCO2A_uatm |
Unit: | µatm |
Observation type: | Surface Underway |
In-situ / Manipulation / Response variable: | In-situ observation |
Measured or calculated: | Measured |
Calculation method and parameters: | Values are interpolated between measurements of xCO2A_ppm |
Sampling instrument: | Licor 7000, IRG4-1045 |
Uncertainty: | 0.2 µatm |
Method reference: | See Pierrot et al. for details. |
SUBMITTED BY: Catherine E. Cosca (Cathy.Cosca@noaa.gov)
SUBMISSION DATE: 2019-08-23