Scientists and engineers at NOAA/AOML frequently participate in cruises in support of the NOAA/AOML eXpendable BathyThermograph (XBT) Network. Recently, Dr. Marlos Goes, a University of Miami CIMAS scientist, gave a short talk to the officers of the Vienna Express, a vessel from the Hapag-LLoyd company, about the importance of the Ship Of Opportunity Program (SOOP) to the success of the XBT Network project.
Marlos Goes gives a presentation to the officers in the Vienna Express, a vessel from the Hapag-LLoyd company, about the XBT project and the importance of the data it collects.
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.
There are approximately 30 XBT transects recommended by the scientific community, one of them being the AX07 transect along 30 N that extends from the Straits of Gibraltar in the eastern Atlantic to the east coast of the United States at Miami, Florida. This transect is visited approximately four times per year, and XBTs are deployed at approximately 25-km intervals along the ship track. The AX07 transect is ideal for monitoring heat flux variability in the Atlantic. The data collected allow scientists to understand how ocean temperature, currents, and sea level change on timescales of days to decades.
Dr. Goes’ informal talk for the officers of the Vienna Express described the goals of the XBT Network project, how data are collected, their use in monitoring, science, and weather forecasts, and details of their transmission and quality control. Much of this information was new to the officers, and they were pleased to be part of the data collection process to better understand our weather and climate, as well as aid navigation through improved weather forecasts. More than 80% of international commerce worldwide is carried out by maritime shipments.
“Observations in this particular transect from Miami to Gibraltar have been ongoing since 1994, therefore for 30 years. One of the scientific applications of these data is to understand how heat is transported northward to the high latitudes, how ocean currents such as the Gulf Stream behave and impact the environment, and how these ocean currents are interconnected in depth and with other latitudes, said Dr. Goes.
The collaboration between scientists and shipping companies, through SOOP, to measure ocean properties is crucial for reaching the goals of scientific programs. Collaboration reduces the cost of operations and number of personnel for NOAA, while ships benefit by collecting critical data that improve maritime forecasts.
“To understand climate and obtain societal benefits from it, we need to collect observations globally, share knowledge, and make recommendations. Climate and weather are affected by many factors, which are all interconnected. These tasks cannot be carried out by one organization only. Therefore, we have many partners across the globe, and work in a very collaborative manner. In the XBT project, we have partners on all continents, civilian and military, which help us deploy observations that are sometimes within exclusive economic zones, and also work together in distributing and analyzing these data, since we share the same goals. The XBT network is very complex to maintain and a strong collaboration between many organizations and countries is needed,” said. Dr. Goes.