Unprecedented flooding is quickly becoming a reality in some coastal communities in Southern California.
High tide Monday morning brought water rushing into Newport Beach’s business districts and flooded a portion of Pacific Coast Highway in Sunset Beach. Sea water levels reached a record high in San Pedro, exceeding 8 feet. Conditions are expected to worsen on Tuesday.
What is happening? After all, Southern California has already experienced El Niño, as well as unusually high tides.
According to scientists, the difference lies in the temperature of ocean waters. Warm water takes up more space than cold water, causing sea levels to rise. This week – even without any former hurricanes in the Pacific Ocean to send swells to the California coast – the maximum sea level recorded at high tide is now nearly 2 feet higher than would be expected from the astronomical forces alone that drive us high tides.
“The waters along the immediate coast of California are actually reaching record heat levels for this time of year, from the Farallon Islands all the way down to Baja California,” Daniel Swain, a UC Agricultural and Natural Resources climatologist, said in an interview Monday.
Because warm water raises sea levels, “current thermal expansion is comparable to, if not greater than, what we’ve actually ever seen before from seawater,” Swain said. “This is starting to lead to quite significant sea level rise, driven both directly and indirectly by El Niño, as well as background ocean warming.”
An analysis of data published on the CyclonicWx website shows sea surface temperatures reaching record highs off the California coast, as well as off the Baja California Peninsula and across a wide swath of the eastern Pacific Ocean. This record dates back to 1982.
There are several reasons why we are seeing what appears to be an unprecedented wave of coastal flooding in recent months.
Part of the problem is the intensity of this El Niño. El Niño is a weather phenomenon that occurs when temperatures in the central and eastern tropical Pacific Ocean – primarily west of Peru – become warmer than normal. And sea surface temperatures are intensely warmer than normal.
“I call it El Niño Macho,” said NASA climate scientist Josh Willis. “It will probably be similar to or larger than 1997, which cost, you know, trillions of dollars in damage worldwide. That was a massive global event, and we’re on track to become as big or bigger.
“Now we’ve also had 20 years of climate change, right? So sea levels are higher,” Willis said.
Sea water levels have risen about 30 cm off the coast of California over the past 125 years.
And the temperatures reach breathtaking numbers.
“It’s over 9 degrees warmer off the coast of South America right now,” Reinhard Flick, a researcher at the Scripps Institution of Oceanography at UC San Diego, said in an interview. And that’s what’s fueling what’s shaping up to be an extraordinarily strong El Niño.
At Scripps Pier in La Jolla, the sea surface temperature was 73.8 degrees Monday, significantly above the calendar day average of 64.7 degrees. That’s 9.1 degrees above average.
“The water was warm all year round off Southern California, but El Niño is now reinforcing that and keeping it warm, where it would naturally go down,” Flick said.
On Monday, at the Los Angeles Harbor in San Pedro, sea levels reached 8.02 feet above the baseline, which is defined as the average daily lowest water level observed between 1983 and 2001. That broke the previous record set during another El Niño, on Jan. 10, 2005, when sea levels reached 7.93 feet.
The reading of 8.02 feet is 1.42 feet higher than would be predicted by the position of the Moon, Earth and sun alone, with the difference being “caused by a combination of thermal expansion due to warmer waters off our coast and the contribution of Kelvin waves, in addition to the very high baseline astronomical high tide,” said David Gomberg, a meteorologist at the National Weather Service office in Oxnard.
Streets were flooded from Newport Beach to Long Beach on Monday. As high tide reached its peak Monday morning, water rose from Newport Harbor onto the streets of the Balboa Peninsula, flooding some businesses in the Balboa Fun Zone. Crews worked to pump out knee-deep water and reinforce sandbags along the peninsula’s harbor.
In Long Beach, residents reported flooding along Bayshore Beach, Naples and the Peninsula. Nancy Pinckert, a Naples resident, recorded video showing water flowing from the base of a levee onto a walkway. “Naples’ seawalls are under profound stress during current high tides,” said Pinckert, who worries that the city hasn’t done enough to replace the aging seawalls in his neighborhood. She said she feared high tides in November and December would “break the sea walls for the first time.”
-
Share via
A Kelvin wave passed earlier this month off the coast of California. It is not a wave that is obviously visible on the sea surface and cannot be surfed, and moves at only 6 mph, but it moves warmer water from the equatorial Pacific Ocean along the coast of the Americas and along the coast of California. Its earlier arrival in October, combined with the effects of swell from Tropical Storm Rachel, contributed to dramatic flooding in homes on the Long Beach Peninsula and on the streets of Newport Beach earlier this month.
Some Californians have noticed how unusually warm the ocean is, and scientists agree. “Absolutely, it’s totally unnatural and it’s bad for the ecology,” Flick said. Sport fishermen may celebrate the arrival of unusual fish, but “if it persists, it’s a serious event for the birds and for the plankton.”
“Much of the California coast is 5 to 9 degrees Fahrenheit warmer than average in terms of water temperature. … It’s really huge,” Swain said. It’s about 9 degrees warmer than average on the Central Coast and 5 degrees warmer elsewhere off Southern California and around the Farallon Islands west of San Francisco, he said.
A second reason is that we are near the peaks of some of the highest tides California has ever seen this century – the so-called 18.6-year lunar node and 4.4-year lunar perigee tidal cycles. They result from small changes in the moon’s orbit and affect tide-generating forces, according to Flick.
This cycle is expected to cause even higher tides around the Thanksgiving, Christmas and Martin Luther King Jr. Day holidays. If a strong storm arrives during these times, it could cause even more severe coastal flooding.
Something similar happened during the historic storm of late January 1983, which occurred during one of the strongest El Niños on record and struck the coast up and down California, damaging many piers. A strong storm arrived precisely at a time of the month when the tides were very high, according to Flick.
Although the pace of coastal flooding may seem incredible to some, it was predicted a few months ago, at a town hall where Mark Merrifield, director of UC San Diego’s Center for Climate Change Impacts and Adaptation, warned that he expected “probably the highest sea levels ever recorded on the California coast associated with this event,” referring to a strengthening El Niño. “Flooding…along the Southern California coast will likely be a major problem for the winter season. »
On the contrary, the floods arrived even earlier than expected. An unusually active hurricane season in the eastern Pacific Ocean — which was expected during an El Niño event — materialized, and remnants of former Hurricane Marie over Labor Day weekend brought saltwater flooding to homes on the Long Beach Peninsula and along Beach Road in Dana Point. A sinkhole has opened in the driveway of actor Nicolas Cage’s Malibu home, forcing the evacuation of dozens of neighboring homes.
Gn usa
