An extreme marine heat wave is sweeping the Pacific Ocean off the coast of California and experts are warning it could impact coastal weather and ecosystems for months.
Heat waves started rising in the ocean late last year, but the situation has worsened in recent weeks Scripps Pier in La JollaWhich has broken more than 25 daily temperature records so far this year. The surface water temperature on Wednesday was 68.5 degrees – 7.7 degrees above the average for that day. The sea level temperature was 67.6 degrees, the hottest April 15 day in nearly 100 years of records.
The heat wave is deep, persistent, and widespread, extending roughly from San Francisco to the Mexican border. “These are pretty significant indicators that this has the staying power and will have consequences for Southern California for weeks or months or even seasons to come,” said Daniel Swain, a climate scientist at the University of California Department of Agriculture and Natural Resources.
Beachgoers play in the water near the Hermosa Beach Pier.
There are several factors contributing to the shocking heat, including an unyielding ridge of high pressure stretching across Southern California and weaker-than-normal coastal winds, which generally move up along the coast. Upwelling occurs when cold, deep ocean water rises to the surface.
But human-caused climate change is undoubtedly pushing temperatures to new records, Swain said, noting that it takes many times more energy to heat ocean water than it does to heat air. “From an ocean warming perspective, we are now entering a very dramatic period for this part of the world,” he said.
El Nino could increase ocean warming even more in the coming months. latest federal approach This includes a 61% chance that El Niño will emerge between May and June and last through at least the end of the year, with a 1 in 4 chance of a particularly strong El Niño. The tropical Pacific climate pattern is associated with hot, wet conditions in Southern California.
This year’s El Niño will end the marine heat wave, but once formed, El Niño will help intensify and continue the marine heat wave, said Dillon Amaya, a research scientist at the National Oceanic and Atmospheric Administration’s Physical Sciences Lab. He said current models predict at least a 70% chance that the marine heat wave will continue off the coast of Baja through December.
“There are places in the world where it is relatively easy to find large ocean anomalies like this, especially the Gulf Stream or the Kuroshio Extension (near Japan),” Amaya said. “But Baja is not one of those places. It’s not easy to get an anomaly of this magnitude, which makes it even more impressive – and terrifying, in my mind.”
This is because this incident is “reminiscent of”the blob” – A massive marine heat wave swept across the Pacific Ocean off the west coast of California from about 2014 to 2016. It brought major disruption to marine ecosystems: mass die-offs of seabirds, fishery disasters, seagrass erosion, whale entanglements, sea lion starvation, fish migration and harmful algae blooms, Amaya said. That hot mass extended along the west coast as far as Canada and Alaska. Was.
A warming Pacific Ocean could mean less ‘May grey’ and ‘June gloom’.
There could also be potential impacts on land, such as reduced oceanic cover, as warmer water temperatures would make it harder for low clouds and fog to develop over land. That means many Southern Californians are hoping for the “May grey” and “June gloom” to subside, Amaya said.
According to Swain, conditions in coastal California could become more humid and muggy due to the end of the cooling fog and more moisture in the warmer air. This could have potential impacts on the health of Californians accustomed to dry heat.
“Ninety degrees isn’t record-breaking heat, but 90 degrees with the humidity is not something people in L.A. are necessarily prepared for,” he said. The same is true for warm nighttime temperatures, which are also likely to occur with this system and could make it harder for people’s bodies to cool down.
Additionally, warmer ocean waters may increase the likelihood of hurricanes and tropical storms off the coast of Mexico. Although such storms typically occur hundreds of miles south of California, the state could still experience the remnants of those systems, as happened with Hillary in 2023, Swain said.
There is less certainty about the impact of wildfires on weather in California. Although more storms and moisture could help extinguish the fires, there is also a possibility that dry lightning storms could fuel the fires, he said.
Scripps Institution of Oceanography researcher Art Miller said the West Coast also saw a marine heat wave in 2019, which he called “Blob 2.0.” It was located in the Gulf of Alaska, off Northern California, and also caused considerable disruption to the ecosystem.
There is some concern that because these North Pacific marine heat waves are occurring with similar — but not exactly the same — “blobs”-like structures, they may be part of a larger adjustment of the Pacific Ocean to climate change driven by greenhouse gases from fossil fuel burning, Miller said, although “the observational record is not long enough to say conclusively.”
“But there is certainly clear evidence that the background average (sea surface temperature) in the oceans in general is increasing, apparently due to global warming, so that warm anomalies riding on long-term warming are occurring with even greater intensity,” he said.
A girl plays in the water near the Hermosa Beach Pier.
NOAA’s Amaya said the current marine heat wave almost certainly would have occurred in the absence of climate change. But the system’s absolute temperature and intensity, “is certainly a function of global warming.”
“As the world continues to warm, each marine heat wave will be hotter than the previous one,” he said.
