Scientists have discovered the first direct evidence of the so-called Gulf Stream “blender effect,” where the waters mix on either side of the current.
The University of Maryland led the research, which is published in the Proceedings of the National Academy of Sciences.
The Gulf Stream is a warm ocean current in the Western North Atlantic. “As the Gulf Stream courses its way up the east coast of the US and Canada, it brings warm salty water from the tropics into the north Atlantic,” the researchers explain in a statement. “But the current also creates an invisible wall of water that divides two distinct ocean regions: the colder, fresher waters along the northern edge of the Gulf Stream that swirl in a counterclockwise direction and the warmer, saltier waters on the southern edge of the current that circulate in a clockwise direction.”
Churning across the edges of the Gulf Stream across areas as small as a kilometer (0.62 miles) could be a leading source of ocean mixing between the waters, according to the experts.
Scientists released fluorescent dye from a buoy and a towing platform that plowed through the sea to examine the churning waters.
“This long-standing debate about whether the Gulf Stream acts as a blender or a barrier to ocean mixing has mainly considered big ocean eddies, tens of kilometers to a hundred kilometers across,” said Jacob Wenegrat, an assistant professor in UMD’s Department of Atmospheric and Oceanic Science and the lead author of the study, in the statement. “What we’re adding to this debate is this new evidence that variability at the kilometer scale seems to be doing a lot of mixing. And those scales are really hard to monitor and model.”
Scientists say that their research has implications for ocean circulation, biology and also climate. “The Gulf Stream plays an important role in what’s known as the ocean biological pump—a system that traps excess carbon dioxide, buffering the planet from global warming,” they explained, in the statement. “In the surface waters of the Gulf Stream region, ocean mixing influences the growth of phytoplankton—the base of the ocean food web. These phytoplankton absorb carbon dioxide near the surface and later sink to the bottom, taking carbon with them and trapping it in the deep ocean.”
“Current models of the ocean biological pump don’t account for the large effect small-scale mixing across the Gulf Stream could have on phytoplankton growth,” they added.
Experts from Stanford University, the University of Massachusetts, Dartmouth, the University of Cambridge, the University of Washington, the University of Victoria and Oregon State University also contributed to the research.
Scientists continue to shed new light on Earth’s oceans and seas. Last year, for example, scientists in Russia discovered a strange “boiling” sea in the waters of the Eastern Arctic. “An unusually powerful methane emission,” caused the phenomenon, according to a translated statement released by Russia’s Tomsk Polytechnic University.
In another project in 2018, a stunning volcanic “lost world” was discovered off the coast of Tasmania.