Gulf of Mexico Hydrographic and Chemical Oceanography Survey

Two hydrographic surveys, N1 and N2, collected data from 94 and 98 stations respectively in the northeastern Gulf of Mexico. The dataset includes continuous profiles of conductivity, temperature, pressure, irradiance, fluorescence, and light transmission, plus water sample analyses for dissolved oxygen and six nutrients. Data were collected by Texas A&M University researchers under contract for the U.S. Minerals Management Service from October 1997 through June 1998.

Use Cases

• Analyze relationships between conductivity, temperature, and pressure profiles to model water density and current patterns.
• Correlate fluorescence and light transmission measurements with HPLC-analyzed phytoplankton pigment data to study algal biomass distribution.
• Model nutrient concentrations (nitrate, nitrite, phosphate, silicate, ammonium, urea) against depth and location across the continental shelf.
• Use ADCP current profiler data alongside hydrographic station data to validate hydrodynamic models of the Gulf of Mexico shelf.
• Assess particulate organic carbon concentrations from filtered water samples to understand carbon cycling in surface and bottom waters.

Strengths

• Data from 192 hydrographic sampling stations across two dedicated research cruises.
• Includes up to 12 water samples per station analyzed for 7 distinct chemical parameters (dissolved oxygen and six nutrients).
• Subjected to stringent quality assurance and control procedures as described in the program report.

Limitations

• Temporal coverage is limited to a single 9-month period from late 1997 to mid-1998.
• Spatial coverage is restricted to the continental shelf and upper slope between the Mississippi Delta and Tampa Bay.
• Sample sizes for specific analyses (e.g., phytoplankton pigments at 51-61 stations) are smaller than the total station count.

Provenance

Source

National Oceanic and Atmospheric Administration, Department of Commerce.

Collection Method

Collected via ship-based hydrographic and ADCP surveys, with water samples analyzed using laboratory techniques like high-performance liquid chromatography.

Time Range

October 1997 through June 1998.

Freshness

Data collection concluded in 1998; the record was last updated in the repository in March 2026.

Geography

Northeastern Gulf of Mexico, continental shelf and upper slope between the Mississippi Delta and Tampa Bay (approx. 29.72N, 86.89W).