Keifu Maru II: Sea Surface CO2 and Salinity Measurements

Surface underway data from the R/V Keifu Maru II captures the partial pressure of carbon dioxide in both the atmosphere and ocean water across the Pacific Ocean, East China Sea, and Sea of Japan. The dataset includes concurrent measurements of sea surface salinity, temperature, and barometric pressure, collected using a carbon dioxide gas analyzer and a shower head chamber equilibrator. Multiple accessions indicate this data collection is part of a sustained, multi-year observational program led by the Japan Meteorological Agency.

Use Cases

• Calculating air-sea CO2 flux based on partial pressure differentials between the atmosphere and water.
• Analyzing correlations between sea surface temperature and pCO2 levels in the western Pacific region.
• Validating regional ocean carbon cycle models with in-situ underway measurements.
• Investigating seasonal variability in surface ocean carbon chemistry across multiple years.

Strengths

• Data collection spans multiple years, with explicit time ranges provided for 2016, 2017, 2018, and 2019.
• Includes simultaneous measurements of five key physical and chemical variables (pCO2-air, pCO2-water, salinity, temperature, pressure).
• Originates from a known research vessel and is associated with a specific, named scientific program (SOOP_Keifu_Maru_II_2015).

Limitations

• Column names and data structure are not specified in any source, hindering immediate analysis.
• Key metadata such as row counts, file size, and license information are consistently absent.
• The primary source (datagov) lists a future 'last updated' date (2026-03-06), which is a conflict and suggests a metadata error.

Provenance

Source

Japan Meteorological Agency (Marine Division, Global Environment and Marine Department); collected by Shu Saito and Keizo Sakurai.

Collection Method

Surface underway observations from the R/V Keifu Maru II using a carbon dioxide (CO2) gas analyzer and a shower head chamber equilibrator.

Time Range

2016-01-07 to 2019-10-19 (aggregated from multiple accessions covering 2016, 2017, 2018, and 2019).

Freshness

2026-03-06 00:24:43.831133 (from datagov, but this appears to be a future date error)

Geography

Pacific Ocean, East China Sea, and Sea of Japan.