New Study: 1979-2013 Southern Ocean And Southeast Pacific Cooling Driven By…Warming?

Scientists attempt to explain why approximately one-third of the global ocean’s sea surface temperatures cooled since the late 1970s.

The 50-70°S Southern Ocean and 160°W to 80°W southeastern Pacific cooled by about -0.35°C (-0.117°C per decade) from 1979-2013 (Yao et al., 2024). (The cooling also continued to 2019, but the authors chose to use 2013 as their end point.)

In the paper the scientists expend a great deal of effort to “argue” that warming in the North Atlantic forced 35+ years of cooling from 50 to 70°S and 160°W to 80°W.

“We argue that North Atlantic warming is decisive for driving the observed multidecadal SST cooling of the southeastern Pacific sector.”

However, they simultaneously acknowledge both (a) internal variability and (b) increases in cloud cover leading to reductions in downwelling shortwave radiation can explain the cooling in this region. These would appear to be much more plausible explanations for multi-decadal cooling than the warming-forces-cooling mechanism they propose.

Image Source: Yao et al., 2024