Voyage of collaboration

AOML ship rider, Dr. Marlos Goes, loads the XBT autolauncher during a recent AX07 transect cruise in May 2024. Credit: NOAA

The NOAA/AOML XBT Network consists of fixed routes, referred to as “transects,” across all ocean basins where XBT instruments collect temperature observations up to half a mile below the ocean’s surface. An XBT or eXpendable BathyThermograph is a probe deployed from a ship when underway that measures the temperature and depth as it falls through the water. A very thin wire transmits the temperature data to the ship where it is then distributed to data centers (e.g., the Global Telecommunication System and NOAA/National Center for Environmental Information) for use in scientific analysis and assimilation in numerical ocean, weather, climate, and ecosystem models. The earliest XBT observations date from the 1950s, with more than two million XBTs deployed since then.

The Ship Of Opportunity Program (SOOP) is an international effort that supports the implementation of a network of cargo vessels, cruise ships, and research vessels to deploy scientific instruments that collect oceanographic observations. The most important component of this effort is the NOAA/AOML XBT Network, a collaboration between NOAA and merchant ship companies where NOAA supplies the shipboard equipment, transmission of data, and technical support, and the shipping companies provide the ship time, personnel, and accommodations when an AOML ship rider is onboard. The fieldwork operations for the XBT Network depend critically on the commitment and support of the shipping companies.