Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset includes dissolved inorganic carbon (DIC), del13C-DIC, and total alkalinity (TA). Samples were collected during transects across the Pacific Ocean from Hong Kong to Long Beach, CA on commercial container ships starting in 2008.

Related Dataset: O2/Ar and triple oxygen isotopes

Samples for carbonate chemistry analysis were collected from shipboard seawater intake (10 m depth) on basin-wide transects of the North Pacific between Hong Kong and Long Beach, California onboard the M/V OOCL Tianjin and the M/V OOCL Tokyo (each individual transect has a unique Cruise ID). Sea surface temperature and salinity at the time of sample collection were determined using a Sea-Bird Electronics SBE45 thermosalinograph installed in the ship’s seawater intake. To prevent biofouling that could cause respiration in the ship’s seawater lines [Juranek et al., 2010], intake lines between the anticorrosive sea chest and the sampling port were purged with bleach and freshwater between every cruise.

Samples for both dissolved inorganic carbon (DIC) and total alkalinity (TA) analysis were collected into 250 mL bottles with greased ground glass stoppers and poisoned with 100 μL of saturated mercuric chloride solution. DIC concentrations were determined in the laboratory through a combination of manometric measurements (DIC_SIL, Quay and Stutsman, 2003) and measurements with an Apollo SciTech AS-C3 IR-based DIC analyzer (DIC_IR). Certified reference materials (Andrew Dickson, UCSD) were used for calibration and determination of sample-specific measurement error for all DIC measurements using the AS-C3 analyzer (DIC_IR_uncert), with mean uncertainty of ± 4 μmol kg^-1 for the entire dataset. Comparison of duplicate samples analyzed both manometrically and with the AS-C3 analyzer (n = 111) agree to within 1 ± 9 μmol kg^-1 and indicate uncertainty of ± 8 μmol kg^-1 in the manometric measurements (DIC_SIL). δ¹³C of the DIC samples measured manometrically was determined following the methods detailed in Quay and Stutsman (2003). TA samples were measured using an automated, open-cell potentiometric titration system (Dickson et al., [2007]; SOP 3b), with sample-specific measurement error quantified based on certified reference materials (Andrew Dickson, UCSD) measured with each sample batch (TA_uncert, mean uncertainty of ± 2 μeq kg^-1 for the entire dataset).

Data are only reported for samples that meet quality control standards (any with problems in the laboratory extraction and measurement process have been omitted in the data spreadsheet).

BCO-DMO Processing:

- added conventional header with dataset name, PI name, version date, reference information
- renamed parameters to BCO-DMO standard
- split date/time into two columns
- reformatted date from m/d/yyyy to yyyy-mm-dd
- replaced blank cells with nd (no data)

This project is an ongoing time-series beginning in 2008 of measurements relevant to ocean carbon cycling and productivity on basin-wide container ship transects across the North Pacific from Hong Kong to Long Beach, California, with transects made throughout the seasonal cycle beginning in October 2008. The goal of this project is to improve our understanding of the rates and mechanisms of ocean carbon uptake from the atmosphere throughout the seasonal cycle and across spatial gradients across the basin. Sampling includes both discrete samples and continuous underway measurements. Tracers sampled in this program include triple oxygen isotopes (δ17O and δ18O), a tracer of gross primary production, oxygen/argon dissolved gas ratios, a tracer of net community production or carbon export, and carbonate system parameters (pCO2, total alkalinity, DIC, and 13C-DIC) as tracers of ocean carbon uptake and carbon cycling.