S-MODE: Shipboard Nitrate Measurements from the 2021 Pilot Campaign

Two weeks of Submersible Ultraviolet Nitrate Analyzer (SUNA) nitrate measurements were collected approximately 300 km offshore of San Francisco during the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE) pilot campaign in October 2021. The dataset contains calibrated optical nitrate sensor data from shipboard CTD rosette casts, validated against bottle nutrient samples analyzed with a Lachat Nutrient Analyzer. It is available in netCDF format and supports research into how short-scale ocean dynamics influence vertical nutrient exchange.

Use Cases

• Calibrating optical nitrate sensor data against discrete bottle samples for method validation.
• Analyzing nitrate distribution patterns in relation to sub-mesoscale physical ocean dynamics.
• Investigating vertical exchange of biological variables using high-resolution nutrient measurements.
• Validating satellite-derived ocean color products with in-situ nitrate concentration data.

Strengths

• Data is calibrated against discrete bottle nutrient samples analyzed with a Lachat Nutrient Analyzer, providing a quality control reference.
• Measurements target a specific, under-sampled spatial scale (sub-mesoscale) over a defined two-week campaign.
• The dataset's cross-platform presence (Data.gov, NASA Earthdata) indicates recognized importance and curation.

Limitations

• Column names and row counts are not provided in any source, limiting immediate understanding of data structure.
• License information is inconsistent ('other-license-specified' vs. null) and lacks specific terms.
• The last updated metadata dates conflict significantly (2026 vs. 2021), raising questions about maintenance.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

SUNA optical nitrate sensor mounted on a shipboard CTD rosette, with calibration from underway system bottle samples analyzed by Lachat Nutrient Analyzer.

Time Range

October 2021

Freshness

2026-04-09 22:52:58.651240

Geography

Approximately 300 km offshore of San Francisco, Pacific Ocean.