{"id":786044,"date":"2026-09-29T05:34:16","date_gmt":"2026-09-29T05:34:16","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/786044\/"},"modified":"2026-09-29T05:34:16","modified_gmt":"2026-09-29T05:34:16","slug":"concern-mounts-over-slow-moving-planetary-scale-kelvin-wave-heading-for-california-california","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/786044\/","title":{"rendered":"Concern mounts over slow-moving, planetary-scale \u2018Kelvin\u2019 wave heading for California | California"},"content":{"rendered":"

Concerns are mounting about an ocean phenomenon known as a Kelvin wave that could raise sea levels along the California<\/a> coastline by up to a foot, as scientists say El Ni\u00f1o is supercharging the threat of storm surges and flooding in the coming months.<\/p>\n

As an incredibly strong El Ni\u00f1o continues to develop in the Pacific, the phenomenon brings with it a strange shift in the ocean. The Kelvin wave phenomenon is created when trade winds that usually blow from South America towards Asia die down or reverse in El Ni\u00f1o years, setting off a massive, slow-moving slosh of water.<\/p>\n

Kelvin waves are not like crashing waves at the beach. They are planetary in scale, spanning thousands of miles. And when a Kelvin wave kicks off, it brings with it an untold amount of warm water that slowly moves from the western Pacific, along the equator, towards South, Central and North America.<\/p>\n

\u201cYou can follow them along \u2026 we see the higher sea levels along the equator, and when the wave reaches the coast of South America, it cannot continue to go eastward,\u201d Severine Fournier, a research scientist studying ocean circulation at Nasa\u2019s Jet Propulsion Laboratory, said. \u201cSo it goes north and south.\u201d<\/p>\n

\"ConcersConcers mounting over slow-moving, planetary-scale \u2018Kelvin\u2019 wave heading for California<\/p>\n

One such wave hit the northern tip of South America in late August and has begun moving up towards the west coast of the US. That wave could reach California shores within days, and when it does, ocean scientists say it may raise sea levels by up to a foot for months as El Ni\u00f1o lingers and keeps that warm water trapped along the coast.<\/p>\n

Nate Mantua, a research scientist at the National Oceanic and Atmospheric Administration\u2019s Southwest Fisheries Science Center, explained that in a typical year, there is a thick layer of warm water in the western Pacific.<\/p>\n

\u201cWhen the wind stops blowing or weakens, the force that\u2019s holding that pile of water in place goes away, so that water surges or sloshes back towards California,\u201d he said, noting researchers expect the influence of the Kelvin wave to linger through the winter and into early next year.<\/p>\n

Mantua said Kelvin waves were a natural phenomenon that have been happening for thousands of years and measured by agencies like Noaa since record-keeping began. But sea levels have already risen about 8in over the last century, meaning Kelvin waves will add more water on top of a figure that\u2019s already going up.<\/p>\n

\u201cWe can predict a lot of the impacts,\u201d he added, \u201cbut not all.\u201d<\/p>\n

A wave crashes into a seawall protecting beachside homes on 7 September in Long Beach, California. Photograph: Mario Tama\/Getty Images<\/p>\n

This year\u2019s El Ni\u00f1o is likely to be the largest in at least 1,000 years. Climate readings have already surged past the highest temperature ever recorded<\/a> for the phenomenon several months before it is expected to peak.<\/p>\n

The climate pattern also brings with it the threat of more severe storms, storm surges, flooding and coastal erosion. For California, all of those effects will happen on top of the sea level rise the Kelvin wave brings, making the threat even worse.<\/p>\n

\u201cIt\u2019s a wave unlike the ones you\u2019re used to at the beach. They don\u2019t crash, you can\u2019t really seem them come by,\u201d said Mike Jacox, a research oceanographer at the Southwest Fisheries Science Center. \u201cThis winter, we\u2019re supposed to have some really high tides around Thanksgiving and Christmas. If you also have more storms, then you have storm surge. It\u2019s just like you\u2019re raising the floor on all that stuff that happens.\u201d<\/p>\n

California is already taking steps to prepare for a potentially catastrophic season.<\/p>\n

This week, the state\u2019s governor, Gavin Newsom, declared a state of emergency, mobilizing resources before any future winter storms, coastal flooding or other impacts. Road-closure and snow-removal equipment is being staged along highways; the state national guard will be prepared for any necessary search-and-rescue efforts; and agencies are finding ways to cut red tape in the event of a natural disaster.<\/p>\n

The California Coastal Commission, which plans and regulates the use of land and water along the state\u2019s coastline, has urged homeowners and residents to prepare now. That includes inspecting any areas vulnerable to flooding or erosion, adding drainage and addressing any causes of damage before severe weather arrives.<\/p>\n

\u201cA key observation from past El Ni\u00f1o events is that the most damaging storms are often those that coincide with the highest tides,\u201d Kate Huckelbridge, the head of the commission, wrote in a memo earlier this month. \u201cStorms that peak during high tides are far more likely to cause damage than if the same storm peaked during low tide.\u201d<\/p>\n

Mantua said past years with exceptionally strong El Ni\u00f1o\u2019s \u2013 1983, 1998, 2016 \u2013 had helped researchers better predict what can happen, and where. But with rising sea levels and the \u201creally exceptional intensity of this event\u201d, he said, \u201cit may end up causing even more damage than we\u2019ve seen in major El Ni\u00f1o winters\u201d.<\/p>\n

\u201cOther things have been happening, right?\u201d he said. \u201cIn the El Ni\u00f1o winters in the northern Pacific, we tend to have a lot of storminess, we tend to have more storms and big storm waves in the ocean than we typically do. So you add that on top of this elevated sea level \u2026 then you just expose places to more of the ocean\u2019s energy and simple inundation.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Concerns are mounting about an ocean phenomenon known as a Kelvin wave that could raise sea levels along…\n","protected":false},"author":2,"featured_media":786045,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[1397,90,56,54,55],"class_list":["post-786044","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-science","tag-uk","tag-united-kingdom","tag-unitedkingdom"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/786044","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=786044"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/786044\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/786045"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=786044"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=786044"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=786044"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}