‘Unprecedented’ failure in the Pacific Ocean stuns scientists
A reliable pattern that occurs off the coast of Panama failed to appear this year
Scientists observed an ‘unprecedented’ failure of a reliable ocean pattern earlier this year, a first in more than four decades of detailed records.
Pacific waters off the coast of Panama typically experience a dramatic temperature drop around the beginning of each year thanks to a complex interaction between the atmosphere and the ocean.
The phenomenon’s conspicuous absence this year could have long-term implications for the region’s economy and ecosystem alike.
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Upwelling is critical to the ecosystem
Upwelling is a natural process that sees chilly water from deep within the ocean rise toward the surface and dramatically cool sea surface temperatures in the region.
This process also draws up rich nutrients from the ocean floor, rejuvenating food sources and increasing productivity for local fisheries.
A recent paper published in the Proceedings of the National Academy of Sciences explored the factors behind the event’s shocking disappearance this year.
The Gulf of Panama experiences a reliable upwelling event every year when the Intertropical Convergence Zone (ITCZ)—an area where trade winds converge—shifts south during the winter.
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Stiff northerly winds funnel south across Panama and over the Pacific Ocean, blowing warm surface water out of the region. Cold water from deep within the ocean then rises to the surface to take its place, forcing sea surface temperatures to plunge.
Data collected since the mid-1980s reveal that upwelling normally occurs by the third week of January and persists for about two months. Each event pushes average water temperatures down to around 19°C, according to the scientists.
This year, however, the upwelling event didn’t begin until early March. Cooler-than-normal waters stuck around for less than two weeks, and average sea surface temperatures only fell to around 23°C.
What happened? Researchers zeroed in on unusually lacklustre wind patterns across the region this year. The team’s analysis found that strong winds weren’t as frequent or persistent as usual, which subdued this year’s upwelling event.
Given the phenomenon’s role in drawing critical nutrients to the surface, this year’s suppressed upwelling could have lingering effects on the region’s marine ecosystem and fishing industry. Persistently warm waters could also add more heat stress to coral reefs that are already struggling against warming oceans.
Header image created using graphics and imagery from Canva and NOAA.