A Hidden Blob of Water Has Abruptly Reappeared in the Atlantic
Scientists have discovered a previously elusive mass of water in the Atlantic by analyzing data from the Argo program. This water mass, known as Atlantic Equatorial Water (AEW), separates the north and south Atlantic along the equator. Understanding these water masses is crucial for studying climate variability and the transfer of heat and nutrients in the world's oceans.
A New Discovery in the Atlantic
For decades, scientists have known about “equatorial waters”—masses of ocean that separate waters north and south of the equator—in both the Pacific and Indian oceans. But a similar mass in the Atlantic has long remained elusive.
A new study by The Shirshov Institute of Oceanology finally discovered this aquatic mass, known as the Atlantic Equatorial Water (AEW), by poring over data available through the international Argo program.
Understanding this water mass—as well as others—will help scientists grasp how the world’s oceans transfer heat and nutrients across the planet.
Unveiling the Hidden AEW
Stare out into the grand expense of the ocean, and it can truly seem endless. Although oceans appear vast and uniform, they’re actually a mixture of roiling layers and masses both connected and split apart by various currents, temperature changes, and salinity variations.
One of these sections of ocean is what’s known as equatorial water, which forms along the equator and separates bodies to its north and south. For decades, scientists knew about equatorial waters in both the Pacific and Indian oceans—they had been detected through the collection of salinity and temperature data. However, a similar mass in the Atlantic remained ever elusive. This has been a particularly sticky problem for oceanologists, because it suggests that the Earth’s other equatorial oceans somehow behave differently than the Atlantic.
Finally, scientists from The Shirshov Institute of Oceanology in Moscow say they’ve found the Atlantic Equatorial Water (AEW) by combing over data provided by Argo, an international program that gathers ocean data using robotic platforms. The results were published in late October in the journal Geophysical Research Letters.
The Importance of Understanding Water Masses
By focusing on temperature and salinity profiles, Viktor Zhurbas—oceanologist at The Shirshov Institute of Oceanology in Moscow and study co-author—and his team refined and supplemented 'a detailed volumetric temperature-salinity diagram' of the upper 2,000 meters of the Atlantic ocean, which allowed them to finally discover the hidden AEW. As its name suggests, this new watery blob separates the north and south Atlantic roughly along the equator.
Understanding these areas of the ocean, and knowing they exist in the first place, is incredibly important. These water masses act as reservoirs of heat, salt, and dissolved gases, all of which reflect climate variability. Studying AEW, as well as other oceanic masses, will also help scientists grasp how the mixing process transfers heat and oxygen around the globe.
The ocean’s complexity and inhospitality to human biology make it less understood than the surface of Mars. However, this recent discovery has brought a moment of clarity to scientists studying the oceans.