In 2015, Southern California waters became very strange.
Pacific Ocean temperatures were up 10 degrees Fahrenheit above average as an unprecedented warming trend spanned Alaska to Mexico.
It was a real sea heat wave.
In a study published Tuesday in the journal Nature Communications researchers concluded that since 1925, the number of ocean currents days has increased by over 50 percent annually, and the frequency of events has increased almost 35 percent. And our warming climate could be to blame.
As the oceans absorb the warmth of a warming earth, average sea temperatures have risen, facilitating the occurrence of extreme seawater warming events.
During the larger heatwave event that caused the event off the coast of Southern California, a number of marine species died, including sea lions, birds and possibly nearly 50 whales.
Unlike heat waves on land, however, marine heat waves absorb much more heat than the air, resulting in long-lived extremes.
"Sometimes heat waves in the ocean can be very long," says Emanuele Di Lorenzo, a marine scientist at the Georgia Institute of Technology's School of Earth and Atmospheric Science, who was not involved in the study, said in an interview [1
Alaskan bears try to delight in a dead fin whale whose death may have been triggered by the ingestion of toxic algal blooms produced by a sea heat wave.
Di Lorenzo cites the "Warm Blob" event 2014-2015 in the Pacific, which lasted over a year.
"It opened everyone's eyes," said Di Lorenzo. "And of course you have massive implications for living things."
When the oceans boil, the consequences for marine inhabitants are likely to be similar to those of geothermal waves for humans.
Terrestrial heat waves are "the deadliest of all weather phenomena," said Bill Patzert, a former NASA climatologist at the Jet Propulsion Laboratory who was not involved in the study. He cites Europe's notorious 2003 heat wave, which killed around 70,000 people.
Marine heatwaves, however, are far from well documented, but they are already known to be devastating, Patzert said. For example, extreme heat waves have repeatedly hit the Great Barrier Reef northeast of Australia. In 2016, such a warming event contributed to the dying of nearly 70 percent of shallow-water corals in a 430-mile pristine reef area.
In this case, a sea heat wave exacerbated already abnormally high sea temperatures. Large parts of the stressed coral were essentially kicked when they were already down.
"It's a compound pain," said Di Lorenzo.
In the study, the researchers attributed these increasing heat wave trends to the rising global ocean average to temperatures. Warmer oceans make it easy for temperatures to rise so high.
"This means that there are times when the heating limits are higher," says Di Lorenzo The researchers of the study have withdrawn the surface temperature data of more than a century ago, the best data come after 1982, said Di Lorenzo. Specifically, this means the inclusion of satellite data collected by National Oceanic and Atmospheric Administration (NOAA) satellites over the course of more than 30 years.
"There is no question that there is a trend," said Di Lorenzo of the increase in the duration and frequency of marine heatwaves. However, he warns that this dataset (1982-2016) is too short to say that the increase in heatwaves is due to climate change. The increase in observed heat waves could actually be due to natural temperature fluctuations in the ocean, as opposed to a consequence of global warming.
Thus, it is clear that the average temperature rise measured in oceans today is undeniable by man-made Climate change is caused. Around 95 percent of solar radiation trapped in the atmosphere is absorbed by the oceans
"The clear evidence of global warming is the warming of the ocean – it's pretty easy," said Patzert.
Extreme warming events in the ocean are most likely to occur in longer-term warming trends that can last for years or more, Patzert said. These include El Niño events in the Pacific Ocean and the longer-term Pacific Decadal Oscillation, which can warm large parts of the Pacific Ocean for decades.
"In a sense, the extreme events in the sea and in the countryside can be more punitive than slower events," said Patzert. The oceans are already suffering from pollution and overfishing. "So when you pile it up with these ocean heat waves, it just makes it worse, it makes it even more devastating."
The sea temperatures will certainly continue to rise this century. However, if there is sustained global effort to mitigate the release of heavy greenhouse gases into the atmosphere, the severity of the increase could be limited.
In the US, however, the government is trying to switch from fossil fuels to renewable energy Solar was blocked by the beleaguered chief of the Environmental Protection Agency, Scott Pruitt. Pruitt hopes to lift the Clean Power Plan, President Obama's plan to protect the nation from fossil fuel burning.
"We live in a warmer world, and we tighten it," said Patzert.