El Niño is coming — the so-called “monster” storms ushered in by the abnormally warm water in the Pacific Ocean near the equator. This warm water can affect weather globally, and in Southern California, experts, including Cal State Fullerton scientists, predict this winter’s El Niño has the potential for extreme rainfall and flooding.
“If I were going to Vegas and betting on the odds for the above-average wet winter this year, I’d be pretty confident and bet large,” said Matthew E. Kirby, professor of geological sciences, who compared it to El Niños in 1982-83 and 1997-98. “All indicators suggest this will be one of the strongest El Niños in recorded time.
“This year brings some unusual conditions previously undocumented for other major historical El Niños. For example, the northeast Pacific is also warmer than average — in fact much warmer than average,” he explained. “How this added ocean warmth will affect this winter’s El Niño remains a debate. I guess we’ll have to wait and see.”
Joe Carlin, assistant professor of geological sciences, agreed about the unusual happenings in the Pacific, including what researchers call the “blob” — warm, surface waters. The blob formed about two years ago in the Northeast Pacific off the coast of Alaska, and in an area off the coast of Southern California, explained Carlin, an expert in marine geology.
“While this blob may be related to the warm waters and El Niño conditions in the equatorial Pacific, the warm water we see off our coast is more blob than El Niño and related to the weather pattern that has been called the “Ridiculously Resistant Ridge,” believed to have contributed significantly to the drought over the past couple of years,” he said.
In addition, a warm phase of the Pacific Decadal Oscillation is occurring. Similar to El Niño, this happens when surface waters warm up on one side of the Pacific and cool down on the other, Carlin added.
A warm phase means the waters of the eastern Pacific, including the local coastal waters, are warming up. The phase can last up to 20 years, such as what happened during the mid-1970s.
“So when we are in a warm phase of the PDO we can expect more frequent and stronger El Niño that will generate more rainfall in Southern California,” Carlin said.
Kirby studies past climate using lake sediments from Southern California lakes, including Lake Elsinore, Zaca Lake and Silver Lake. The influence of El Niño-like conditions on the winter climate in the region is an old phenomena that has impacted the region for a long time, although frequency and magnitude vary over time, he explained.
“In the case of the coastal southwest United States, my research indicates a tight coupling between tropical Pacific Ocean conditions and winter wetness over the past 15,000 years,” said Kirby.
“If my research on the past relationship between the tropical Pacific Ocean and winter climate is any indicator of future relationships, I expect a wetter-than-average winter this year.
“As the equatorial Pacific Ocean warms in response to rising global temperatures, we also might expect wetter than average winters in the future, as well. However, the latter remains highly speculative.”
The expected heavy storms will help improve California’s existing drought conditions, but will not end it, said Kirby. It’s all about how much water California gets in the right places.
“California relies on transported water, so it’s critical to get snow in the Sierras, the northwestern region of the state and Colorado,” he said. “Locally, more water is good for our local reservoirs and our groundwater storage, but we really need water in the three areas noted to take any significant bite out of this drought. Importantly, snow is preferred over rain because it represents a longer lasting natural reservoir than rain.”
While campus emergency and facilities teams prepare for the oncoming storms, scholars in the Department of Civil and Environmental Engineering emphasize the need for such readiness. They’re studying the effects of storms and floods, in order to develop means to lessen landslide hazards and envionmental damage when natural disasters hit.