MRI Hakuho Maru II: Ocean Carbon and Meteorology from Surface Underway Measurements

Four research cruises (KH01-3, KH90-2, KH90-3, KH94-4) collected surface underway data from 1990-09-03 to 2002-01-21 across the Pacific, Indian, and Southern Oceans. The dataset includes measurements of dissolved inorganic carbon, carbon dioxide partial pressure in air and water, total alkalinity, salinity, sea surface temperature, air temperature, barometric pressure, and wind. Data were collected using autonomous DIC sensors and CO2 gas analyzers aboard the Hakuho Maru vessel.

Use Cases

• Estimating ocean carbon sink strength based on partial pressure of carbon dioxide in water and atmosphere.
• Analyzing relationships between sea surface temperature, salinity, and dissolved inorganic carbon concentrations.
• Modeling air-sea gas flux using concurrent wind speed, barometric pressure, and carbon dioxide measurements.
• Studying decadal changes in surface ocean alkalinity and carbonate chemistry across multiple ocean basins.

Strengths

• Covers a 12-year time series from 1990 to 2002, providing a multi-decadal perspective.
• Includes co-located chemical, physical, and meteorological variables enabling integrated analysis.
• Data collection used specialized autonomous instruments for dissolved inorganic carbon and CO2.

Limitations

• Key metadata such as row count, file size, specific column names, and license are not provided on any platform.
• Conflicting 'last updated' dates (2002-01-21 vs. 2026-03-05) create uncertainty about metadata freshness.
• The dataset's spatial coverage, while broad, is defined by specific cruise tracks and may not be uniformly distributed.

Provenance

Source

Hisayuki Y. Inoue (Hokkaido University) and Masao Ishii (Meteorological Research Institute)

Collection Method

Surface underway observations from the research vessel Hakuho Maru.

Time Range

1990-09-03 to 2002-01-21

Freshness

2026-03-05 23:52:23.172614

Geography

Bismarck Sea, Coral Sea, Indian Ocean, North Pacific Ocean, Philippine Sea, Solomon Sea, South Pacific Ocean, Southern Oceans (>60 degrees South), Tasman Sea