AOML's Ocean Chemistry and Ecosystems Division

About the Gordon Gunter

A picture of the Gordon Gunter at sea.

The NOAA Ship Gordon Gunter, commissioned on August 28, 1998 was originally the U.S. Naval Ship RELENTLESS. Beginning in March 1998, the ship was refitted to contain modern navigational electronics, oceanographic winches, sensors, sampling equipment, and a custom-designed marine mammal observation and survey station. With a home port of Pascagoula, Mississippi, the Gordon Gunter operates primarily in the Gulf of Mexico, Atlantic and Caribbean waters. For more information on the Gordon Gunter, follow the link to its homepage.

In March, 2008, the Ocean Carbon Cycle (OCC) group at NOAA's Atlantic Oceanographic and Meteorological Laboratory (AOML) installed an underway system to measure surface pCO2 in the Hydro Chem Lab aboard the Gordon Gunter. In August 2010, the underway system was replaced with a newer version system that could be connected more easily to the ship and other sensors. The installations were greatly facilitated by the cooperation of the ship's officers and crew, especially the operation officers and electronic technicians. While the ship conducts the research that is the focus of a cruise, the pCO2 instrument takes 5 air and 60 water measurements every 3 hours. Data files are sent to AOML via email every day so that the system operation can be monitored. The final data are processed after a cruise is completed and then posted to international databases and to this web site.

About this Website

This web site provides access to the fugacity of CO2 (fCO2) data collected on this ship. Note, fCO2 is the partial pressure pCO2 corrected for non-ideality of the CO2 gas; they are numerically similar (fCO2 ≃ 0.995 pCO2). The processed data are organized by year and by cruise. For each cruise, the color coded fCO2 values are plotted along the ship's cruise track on a chart. Next to each chart are links to the comma-delimited data file and the associated Readme file. To download a data file, select the year from the drop-down list box and click on GO. Choose a chart and cruise, right-click on the link to its data file or Readme file, and select the download option. Please consult with and acknowledge the AOML Ocean Carbon Cycle group if data is used for publication or presentation (contacts in Master Readme, or

The Master Readme link in the menu bar on the left provides meta data that is applicable for all data gathered from this ship. The individual Readme files next to the charts provide meta data specific to the associated cruise. The Realtime Display link displays plots of the raw xCO2 data as a function of time and location. These plots are suitable for monitoring but are not suitable for environmental interpretation since the Realtime data has not been processed nor quality controlled.

Data Downloads

All of the data available via these web pages are also available through the Gordon Gunter Landing Page at NCEI. The NCEI Landing Page is organized as a table with a row for all of the cruises within a year.