Story at a glance:
- The ocean’s eddies are getting stronger.
- It’s due to climate change, but the research doesn’t specifically call out human activity.
- Ninety percent of the global heating and 40 percent of carbon dioxide are absorbed by the oceans.
Many of the ocean's currents are getting stronger in what scientists are referring to a “global-scale reorganization” within the past three decades.
Ocean eddies, comparable to atmospheric weather, are the swirling motion of fluid in the water, and it is said that the amount of energy in these ocean currents is increasing — the eddies span from 6.2 miles (10km) to 62 miles (100km) across.
Eddies help control different temperature water across the ocean, mixing heat, carbon, salt and other nutrients worldwide.
Lead researcher Josué Martínez Moreno, of the ARC Centre of Excellence for Climate Extremes and Australian National University, said the eddies regularly joined and withdrew from strong ocean currents.
The research, Moreno said, shows that there is “a global-scale reorganisation of the ocean’s energy over the past three decades.” The scientists did not attempt to link human activity to the changes in the ocean. However, Moreno said this could have extended effects on the world’s climate and fisheries.
Understanding the changes in ocean eddies could also improve climate change projections, Moreno said.
The ocean has been absorbing about 90 percent of global heating since the 1970s and 40 percent of carbon dioxide that was emitted into the atmosphere, mainly from fossil fuel burning, since the start of the Industrial Revolution.
“The world’s oceans soak up most of the carbon dioxide that humans dump into the atmosphere. The Southern Ocean in particular absorbs about 40% of the entire ocean uptake and much of that uptake is achieved by ocean eddies,” Janet Sprintall, an oceanographer at the Scripps Institution of Oceanography in California who was not involved in the research, told The Guardian.
The Southern Ocean, she said, if changed by the ocean eddies, could “potentially impact the carbon sink and the ability to uptake carbon that we might continue to emit in the future."
As sea levels are rising, coasts are beginning to erode, water is overheating and acidifying, and dead zones or deoxygenated water are forming that threaten 90 percent of mangrove, seagrass, and marsh plant species into extinction.
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