U.S. JGOFS Arabian Sea Study: Thorium-234 Activity in Particulate and Dissolved Components

Eleven research cruises aboard the R/V Thomas G. Thompson collected water samples from October 1994 to January 1996 in the Arabian Sea southeast of Oman. The dataset contains thorium-234 activity measurements in decays per minute per liter (dpm/l) and particulate organic carbon/nitrogen concentrations in micromoles per liter (umol/l), fractionated into size classes. This data was collected as part of the U.S. Joint Global Ocean Flux Study (JGOFS) to understand carbon cycling driven by monsoon cycles.

Use Cases

• Estimating particle and carbon fluxes based on thorium-234 activity measurements.
• Analyzing seasonal carbon cycling dynamics based on monsoon and inter-monsoon cycle coverage.
• Modeling particulate organic carbon (POC) and nitrogen (PON) concentrations in the water column.
• Comparing particle size fractions (greater than 53 microns and 1-53 microns) for biogeochemical studies.

Strengths

• Provides seasonal coverage of the annual monsoon and inter-monsoon cycles over approximately sixteen months.
• Includes thorium-234 activity, particulate organic carbon (POC), and particulate organic nitrogen (PON) measurements with size fractionation.
• Data is public domain and was originally accessible via the U.S. JGOFS website.

Limitations

• Last updated 1996-01-31 23:59:59.999000; freshness should be verified.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

U.S. Joint Global Ocean Flux Study (JGOFS) and the Cafe Thorium website at WHOI.

Collection Method

Water samples collected by in situ pump (the Slurper) at surface and discrete depth levels during research cruises.

Time Range

October 1994 to January 1996

Freshness

Last updated 1996-01-31 23:59:59.999000

Geography

Arabian Sea, southeast of Oman