Discrete measurements (TCO2, TALK, pCO2, and pH) metadata form
- Investigator:
- Name: Yager, Dr. Patricia L.
- Organization: University of Georgia - School of Marine Programs
- Address:
Department of Marine Sciences
220 Marine Science Bldg
Athens, Georgia 30602-3636
USA
- Phone: 706-542-6824
- Email: pyager@uga.edu
- Dataset Info:
- Dataset ID: MP9
- Submission Dates:
- Initial Submission: 2006/06/19
- Revised Submission:
- Cruise Info:
- Experiment:
- Experiment Name: Carbon Sequestration / Biocomplexity Project
- Cruise:
- Cruise ID: MP9
- Section:
- Geographical Coverage:
- Geographical Region:
Subtropical North Pacific Ocean - Bounds:
- Westernmost Longitude: +169.99
Degrees, Minutes, Seconds: E - Easternmost Longitude: -154.82
Degrees, Minutes, Seconds: E - Northernmost Latitude: 28
Degrees, Minutes, Seconds: N - Southernmost Latitude: 18.5
Degrees, Minutes, Seconds: N
- Temporal Coverage:
- Start Date: 2003/07/14
- End Date: 2003/08/21
- Ports of Call:
Honolulu. Hawaii USA
- Vessel:
- Vessel Name: R/V Roger Revelle
- Vessel ID:
- Country: USA
- Vessel Owner: Scripps Inst. Oceanography
- Variables Info:
- Variable:
- Variable Name: Pressure
- Description of Variable: dbar
- Method Description:
- Total C02 Data:
- TCO2 Analysis Method:
Samples collected and stored cold and dark until processed (DOE, 1997). Analyzed in the laboratory at UGA using a SOMMA (Single Operator Multi-Metabolic Analyzer) connected to a CO2 coulometer (UIC, Inc) interfaced to a PC. See Johnson et al., 1993; 1998. - Standardization Technique:
- Technique Description
The instrument was first calibrated using a standard CO2 gas (99.999%). Certified Reference Material (Dickson 2001) was run twice at the start of every day, after every ten samples, and at the end of the day. Unless daily drift was detected (rare), then we computed the average CRM for the day, calculated the ratio of the expected CRM value to the measured value, and multiplied all the data by this ratio. In the rare case of drift, we corrected to the nearest CRM. - Sample Volume(mL):
- CRM Info:
- Correction Magnitude: Average coffection factor = 0.99602396 (stdev = 0.01203377; n = 329)
- Batch Number:
64
65 - CRM Analysis Info:
The average (±95% ci) of the first CRM run of each day was 2091.008 (± 2.76) umol/kg for Batch 64 (n = 3) and 1994.586 (± 0.271) umol/kg for Batch 65 (n=22). The standard deviations were 1.112 umol/kg and 0.611 umol/kg for Batches 64 and 65, respectively. The expected value for Batch 64 was: 2090.89 umol/kg and the expected value for Batch 65 was 1993.68. The slope (±95% ci) of the trendline of the first daily CRM observed minus expected value versus time over the length of the cruise analysis (117 days) was -0.0071(±0.00392; R^2 = 0.126) umol/kg/day. System drift thus reduced accuracy over the 4 months, but individual analysis days were corrected according to daily standards so there should be no drift in the data. Precision (sR) based on replicate runs of the first daily CRM was 0.332 umol/kg.
- Field Replicate Info:
- Poisoning Info:
- Poisoning Correction Description:
To each sample (590 mls), we added 200 uL of a saturated (at 25°C) solution of mercuric chloride. Each DIC data point has already been multiplied by a dilution factor of 1.000338983. - Poison Volume(mL): 0.2
- Accuracy Info:
Accuracy was insured by daily corrections to average CRM. Instrument precision (sR, based on replicate runs from same CRM bottle) = 0.332 umol/kg. Sample precision (sR, based on duplicate samples collected from same Niskin bottle)=0.607 umol/kg. - Method References:
Johnson, K. H., K. D. Wills, D. B. Butler, W. K. Johnson (1993). Coulometric total carbon analysis for marine studies: measuring the performance of an automated gas extraction system and coulometric detector. Marine Chemistry 44: 167-187.
Johnson, K. H., A. G. Dickson, G. Eischeid, C. Goyet, P. Guenther, R. M. Key, F. J. Miller, D. Purkerson, C. L. Sabine, R. G. Schottle, D. W. R. Wallace, R. J. Wilke, and C. D. Winn (1998). Coulometric total carbon analysis for marine studies: assessment of the quality of total inorganic carbon measurements made during the US Indian Ocean CO2 survey 1994-1996. Marine Chemistry 63: 21-37.
Cooley, S. R., and P. L. Yager (in press 2006). Physical and biological contributions to the western tropical North Atlantic Ocean carbon sink formed by the Amazon River Plume. J. Geophys. Res. Oceans.
- Alkalinity:
- Curve Fitting Method:
Calculated using the modified gran approach (Dickson et al., 2003) - Type of Titration: Potentiometric titration using an automated burette with 0.1N HCl in 0.7 M NaCl
- Description of Other Titration:
- Cell Type: open-cell
- CRM Scale:
- Sample Volume(mL):
- Magnitude of Blank Correction: none used
- Accuracy Info:
CRMs were used as primary alkalinity reference standards to back calculate titration acid concentration. This forced the absolute accuracy of samples to CRM standards. Instrument precision (sR, based on duplicate runs of each CRM) = 2.992 ueq/kg. Sampling precision (sR, based on duplicate samples collected in series from the same Niskin bottle) = 1.428 ueq/kg. - Method References:
Dickson, A. G., J. D. Afghan, G. C. Anderson (2003). Reference materials for oceanic CO2 analysis: a method for the certification of total alkalinity. Marine Chemistry 80: 185-197.
Cooley, S. R., and P. L. Yager (in press 2006). Physical and biological contributions to the western tropical North Atlantic Ocean carbon sink formed by the Amazon River Plume. J. Geophys. Res. Oceans.
- pCO2 Data:
- Analysis:
- pCO2 Analysis Method:
- Sample Volume(mL):
- Headspace Volume:
- Measurement Temperature:
- Temperature Normalization:
- Temperature Correction Method:
- Variable Reported:
- Gas:
- Standard Gas Concentrations:
- Frequency of Standardization:
- Field Replicate Info:
- Storage Method:
- Accuracy Info:
- Method References:
- pH Data:
- pH Scale:
- pH Analysis Method:
- Calibration Info:
- Calibration Description:
- In Situ Temperature:
- Temperature of Analysis:
- Temperature Normalization:
- In Situ Pressure:
- Accuracy Info:
- Method References:
- Additional information:
For more information about MP cruises, go to: http://biology.usc.edu/bc/ - Data Set References:
- Citation:
Patricia L. Yager (unpublished data) - Data Set Link: