El Niño conditions this year might lead to unprecedented sea levels along California’s coast, increasing the risk of extensive flooding. Forecasters expect this El Niño to be historically strong, potentially bringing heavy rains to Southern California and causing extreme heat waves.
Record Sea Levels Predicted
Mark Merrifield from UC San Diego’s Scripps Institution of Oceanography stated that this event could produce the highest sea levels recorded in the state. Recent data from NASA reveal that sea levels in the eastern Pacific are already over six inches above their standard levels. By fall and winter, sea levels could greatly exceed typical seasonal patterns.
El Niño warms ocean surfaces, displacing cooler water and leading to higher sea surface heights. The process is already causing a rise in sea levels across the eastern Pacific. Merrifield also noted that past El Niño events produce strong waves, which can lead to beach erosion. He mentioned that shorelines tend to move inland by roughly 30 meters during these periods.
Impact of Rising Sea Levels
The combination of high waves, sea levels, tides, and rainfall is likely to contribute to severe coastal flooding, seawater intrusion, and erosion. Specific problems, such as flooding on the Southern California coast, are anticipated for the winter season.
A look at recent El Niño events like those in 1982-83, 1997-98, and 2023-24 shows significant flooding in Ventura, Los Angeles, and San Diego counties. For instance, a sneaker wave in Ventura caused injuries in late 2023.
Climate Change and El Niño
El Niño magnifies existing climate change trends, such as rising sea levels in San Francisco Bay Area. In previous El Niño seasons, sea levels in San Francisco rose by half a foot to a foot. Merrifield mentions these spikes generally peak from November to December.
El Niño Characteristics
El Niño occurs when ocean waters in the central and eastern tropical Pacific warm up, disrupting normal trade winds. This can lead to significant rainfall in Southern California, even as it results in drier conditions elsewhere.
The upcoming El Niño may rank among the strongest recorded. UC climate scientist Daniel Swain indicated that current temperatures in the eastern tropical Pacific are unprecedented for this time of year.
Precautions and Environmental Concerns
Preparations for a potentially stormy winter are underway. Swain noted that more intense rainfall is probable, especially from December through March. El Niño could also extend marine heat waves off the coast, impacting marine ecosystems and triggering harmful algal blooms.
The California Department of Fish and Wildlife plans to monitor domoic acid levels due to warmer waters. Past incidents of increased domoic acid have disrupted the Dungeness crab season. The neurotoxin can harm both animals and humans, causing serious health issues.
Marine heat waves have also led to a substantial decline in Northern California’s bull kelp habitats, affecting various species. Additionally, Southern California is experiencing uncharacteristically humid conditions due to elevated ocean temperatures.