The fast-melting ice in the Arctic may be the primary cause of extreme weather across the globe, including some of the most violent, damaging storms to hit the Bay Area and California, a Scripps Institution of Oceanography study has found.

The Scripps paper, published Monday in the journal Proceedings of the National Academy of Sciences, is the first definitive study of the links between melting polar ice and changing climatic conditions reaching to the tropics, a cause-and-effect relationship that scientists had plenty of evidence for but had never precisely documented to this extent.

The study provides evidence that the melting ice sets in motion a chain of events, including major disruptions in wind and weather patterns at the equator and in the central Pacific Ocean. That, in turn, can trigger El Niño weather events and the violent “atmospheric rivers” that bring deluges of rain, sometimes causing havoc in the Bay Area.

The changes in atmospheric convection documented in the report could also influence occasional balmy periods during California winters that coincide with record cold in the Midwest, said Charles Kennel, a physicist and the former director of the Scripps Institution, which is based at UC San Diego.

“There’s a definite relationship and a change in tropical Pacific climate,” said Kennel, who, with colleague Elena Yulaeva, used computer analysis to identify atmospheric changes as Arctic ice diminished. “There’s now a network of consistent correlations.”

Scientists say ice cover in the Arctic has been shrinking for at least two decades. A special report released in September by the U.N. Intergovernmental Panel on Climate Change documented a decline in thickness and extent so dramatic that scientists believe the Arctic Ocean will occasionally become ice-free if nothing is done to halt global warming.

The panel said the warming sea has influenced atmospheric circulation patterns, resulting in extreme weather in many places, including Northern California. It predicted stronger, more frequent storms, longer droughts and an increase in the marine heat waves that recently ravaged the ocean ecosystem along the West Coast.

“The Arctic is changing rapidly,” Noah Diffenbaugh, a climate scientist at the Woods Institute for the Environment at Stanford University, said after the IPCC report was released. “The most immediate impacts are for the ecosystem and people in the Arctic, but there is strong evidence of impacts on ... conditions that we experience here in California.”

Kennel and Yulaeva explained in their Scripps report that ice reflects sunlight, so the less ice there is in the Arctic Ocean the more heat gets absorbed.

Average ocean surface temperatures have been increasing two to three times faster than average surface temperatures around the globe, the study authors said.

“In August and September, the ocean warms up tremendously,” Kennel said. “It’s like turning on the burner of a stove for about a month.”

The water below the ice sheet is typically just above the 28.8 degree Fahrenheit freezing point of saltwater, but water temperatures in the Arctic are influenced by global sea surface temperatures, which have increased a little more than 1 degree on average over the past century.

A recent study in the journal Advances in Atmospheric Sciences showed the rate of increase in sea surface temperatures from 1987 to 2019 was 4½ times faster than it was between 1955 to 1986.

Scientists now predict that winter temperatures in the Arctic will rise as much as 9 degrees Fahrenheit by 2050, even if the world meets its most ambitious carbon emissions reduction targets. As it is, climate scientists estimate that Arctic sea ice has declined 40% over the past 40 years.

The late summer warming in the Arctic is the key to everything, Kennel said. The warmed-up water causes air to rise into the troposphere, the lower part of the atmosphere that extends from the earth’s surface 6.2 miles upward to the boundary of the stratosphere. This convection system moves south toward the equator.

Many researchers doubted the Arctic air could reach the equator, but the Scripps study suggests it does.

The phenomenon appears to disrupt and intensify trade winds at the equator and over the Pacific Ocean, one of the biggest drivers of global climate.

The Scripps study suggests these wind patterns have influenced the buildup of warm equatorial water in the Central Pacific, a phenomenon known as El Niño.

“It gradually affects the climate elsewhere,” Kennel said. “We have evidence that it affects the trade winds and the processes that make for an El Niño cycle near the tropical Central Pacific.”

That, in turn, has increased the strength of atmospheric river-type storms in California, led to frigid polar vortexes in the Midwest and precipitated flooding in Asia.

“These results add to the evidence that loss of Arctic sea ice is having a major impact on climatic variability around the world,” the authors wrote in the study. “The magnitude of Arctic sea ice loss and the strength of the Central Pacific trade winds are unprecedented in the instrumental record.”

Atmospheric rivers, which are long bands of water vapor in the atmosphere that are pushed by strong winds, have inundated the West Coast with torrential rain and flooding and buried the Sierra and Cascades in snow. They have also hit the East Coast and Europe.

Such storms have delivered as much as half of California’s annual precipitation during wet years and caused 90% of the flooding in the state, Scripps officials have said.

The more powerful ones can be as strong as a Category 5 hurricane. Dozens hit California during the winter of 2016-17, when one storm dropped so much water that releases from Oroville Dam caused a torrent that damaged the spillway, forcing authorities to evacuate nearly 200,000 people downstream.

More research will need to be done to confirm the links, but altered atmospheric circulation patterns caused by Arctic warming may also have something to do with the warm patch of water dubbed the “blob” that played havoc with the marine ecosystem, including the deaths of about 1 million seabirds known as common murres and 90% of the kelp along the Pacific coast from 2014 to 2016.

That marine heat wave was linked to a 40-mile wide algae bloom in 2015 that poisoned sea lions, salmon and Dungeness crab, prompting California wildlife officials to close the commercial crab season.

The loss of kelp is a perfect example of how one thing, like warming water, can cause a cascade of problems. Because there was so little kelp to eat, red abalone starved from Baja California to Alaska. The red abalone fishery was closed in 2018 because of the die-off.

Also, the recovery of California sea otters, which use underwater kelp forests as cover, has stalled largely because the loss of kelp led to more great white shark attacks, according to marine biologists.

The U.N. report last year said marine heat waves have doubled in frequency globally since 1982 and are expected to occur as much as 50 times more often by the end of the century if nothing is done to stop climate change.

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite