Ocean currents will have more intense heat waves as climate warms

Several studies have shown the intensity and frequency of marine heatwaves are on the rise.  Photo by Pexels
Several studies have shown the intensity and frequency of marine heatwaves are on the rise.  Photo by Pexels

Aug. 28 (UPI) -- Regions of the ocean that host especially strong currents are more likely to experience intense marine heat waves in the decades ahead, according to a new climate model.

Several studies have shown the intensity and frequency of marine heat waves are on the rise. New research -- published Friday in the journal Nature Communications -- suggests the intensity of marine heat wave events will increase at an accelerated rate near large ocean currents.

According to the new model, the North Atlantic's Gulf Stream, Japan's Kuroshio current, the the Antarctic Circumpolar Current and two major currents near Australia, the Leeuwin current and East Australian Current, will all experience more intense heat waves as the climate continues to warm.

"We know marine heat waves are on the rise globally, but policymakers, fisheries experts, aquaculture industries and ecologists need to know how this will play out at regional levels, especially in terms of where they will occur and how much hotter they will be," lead author Hakase Hayashida, researcher with the ARC Center of Excellence for Climate Extremes in Australia, said in a news release.

"Our detailed modeling is the first step in peeling back these layers, revealing the temperature variation that occurs across these currents and around them, indicating where the sharpest rises in marine heat waves are likely to occur," Hayashida said.

In Australia, simulations showed increasingly intense heat waves will form far from Tasmania's shoreline, but in North America, heat waves along the Gulf Stream are likely to form closer to the coastline, from Virginia to New Brunswick.

"This will almost certainly change ecosystems in these regions," Hayashida said.

For the study, researchers combined the results from two near-global, high-resolution ocean warming models built by scientists with the CSIRO Ocean Downscaling Strategic Project. Scientists ran simulations for current and future warming periods. The analysis revealed more precise geographical differences in extreme ocean heat.

When researchers compared the results of their novel modeling approach with real world ocean warming records from 1982 to 2018, they found significant agreement among the data sets.

The simulations also showed that risk of extreme ocean temperatures dissipates as smaller, weaker currents peel off and diverge from major ocean currents.

"Like so many aspects of the climate system, the warming of the oceans isn't the same everywhere, which means the ecology will respond differently to global warming, depending on location," said study co-author Pete Strutton, professor of biological oceanography at the University of Tasmania.

"Detailed modeling like this is the first step in understanding which ecosystems will thrive or decline, how the productivity of the ocean will change, and those parts of the food chain most likely to be affected," Strutton said. "This is exactly the kind of knowledge we need to adapt to the inevitable consequences of global warming."

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