NOAA/CMDL Trace Halocarbons: Underway Surface Ocean Measurements, 1994-2004

Over a decade of measurements from 1994-01-28 to 2004-07-02, this dataset contains underway surface observations of trace halocarbons, CFCs, and environmental variables collected during seven major research cruises across global oceans. It includes concentrations of specific compounds like CFC-11, CFC-12, methyl bromide, and methyl iodide, alongside core oceanographic and meteorological parameters such as salinity, water temperature, air temperature, wind speed, and photosynthetic active radiation. The data support the CLIVAR Global Ocean Carbon and Repeat Hydrography Program's goal to quantify changes in ocean heat, freshwater, and carbon storage.

Use Cases

• Analyzing temporal trends of ozone-depleting substances (CFCs) and other halocarbons in surface seawater across multiple ocean basins.
• Correlating trace gas concentrations (e.g., CH3Br, CH3I) with concurrent physical conditions like water temperature, salinity, and wind speed.
• Investigating air-sea flux estimates for halogenated compounds using underway meteorological and chemical data.
• Calibrating and validating ocean carbon cycle models with in-situ measurements from repeat hydrography sections.
• Studying phytoplankton activity through the relationship between fluorescence and photosynthetic active radiation (PAR) measurements.

Strengths

• Covers a specific 10.5-year time range from 1994 to 2004, providing a decadal-scale snapshot.
• Includes measurements from seven distinct research cruises (e.g., BACPAC, BLAST I-III, GasEx 98) across a global network of ocean regions.
• Contains a detailed list of over 25 measured variables, including specific chemical species and core environmental parameters.
• Data is associated with a major international climate research program (CLIVAR), indicating scientific rigor.

Limitations

• Critical metadata is missing: row count, file size, column definitions, and license information are not provided on any platform.
• Conflicting 'last updated' dates exist (2026-03 05 and 2004-07-02), creating uncertainty about metadata maintenance.
• The dataset's structure and granularity (e.g., sampling frequency, data format) are unclear from the available descriptions.

Provenance

Source

James W. Elkins and James H. Butler of NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL)/Earth System Research Laboratory (ESRL).

Collection Method

Underway surface observations collected using a PAR Sensor and other instruments aboard multiple research vessels.

Time Range

1994-01-28 to 2004-07-02

Freshness

The most recent platform update noted is 2026-03-05, but the data collection ended in 2004.

Geography

Bering Sea, Caribbean Sea, Gulf of Alaska, Gulf of Mexico, Indian Ocean, North and South Atlantic and Pacific Oceans, including several U.S. National Marine Sanctuaries.