PAOC oceanographer and chair Raffaele Ferrari and postdoc Ali Mashayek recently attended the 2016 Ocean Sciences Meeting of the American Geophysical Union in New Orleans, where they presented a new look into how turbulence in the deep ocean may be driving global currents. Their work caught the attention of many, including the journal Nature.
Ocean currents mix water vertically from the surface to the deep sea, as well as transport warm water to the poles and cold water toward the equator in a “global conveyor belt”. Small-scale turbulence in the ocean’s interior has long been thought to bring the deep cold water towards the surface. “Now, some researchers [Ferrari, Mashayek, McDougall, and Nikurashin] are rethinking the role of this turbulence — turning it upside down. Using computer simulations fed with measurements from the field, they argue that small-scale turbulence drives circulation by pushing water in the ocean’s interior down, not up,” wrote Devin Powell for Nature.
Waters of different densities and temperatures form layers within the ocean, and as they interact with each other, waves can form and crash in the ocean’s interior causing chaos in the deep sea. “This rolling in the deep inverts the effect of turbulence, the MIT group argues. It causes upper, less-dense layers of water to mix into lower, denser layers — pulling massive flows down in the middle of oceans.”
Work like Ferrari’s and Mashayek’s has implications that extend beyond the water. Understanding how the ocean moves can help explain its effects on the climate, as well as the ocean’s ability to store carbon and heat.
Read more about Ferrari and Mashayek’s research on ocean turbulence and how it may help explain historical observations like the “missing mixing problem” in Nature and EAPS News.