Six things scientists say you need to know about El Niño

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As the near-certainty of a record-breaking super El Niño has become clear, the scientists who predict and study it have been inundated by inquiries from the press and public. While there seems to be widespread recognition of what the term “El Niño” means, many people are confused about how El Niño may affect them and its ties to extreme weather events, among other things.

Here are the top 6 confusing things about El Niño, as relayed to CNN via meteorologists and climate scientists.

Scientists talk about likely outcomes enough that it’s easy to assume all El Niño events have the same impacts — that an El Niño year will mean more rain in California, for example. But each El Niño event is actually distinct. You can see that in the way the 2015-to-2016 super El Niño failed to deliver excessive rainfall to California, despite predictions — based on previous super El Niño events — that it would.

Part of the reason for the idiosyncratic nature of El Niño events is that they don’t act alone, but instead interact with other influences on weather patterns, such as the polar vortex and different ocean and atmospheric weather and climate cycles.

According to veteran El Niño researcher Michael McPhaden, El Niño comes in all shapes and sizes, and “no two are exactly the same.”

“There’s a tremendous amount of chaos in the climate system,” he said.

It can be tempting to view El Niño — and the extreme weather events it contributes to — as all bad news. But some areas can benefit from this climate cycle. For example, the Atlantic hurricane season has been unusually quiet this year, with just one hurricane forming so far (though it unfortunately struck the US ).

Why this El Niño is so strong

That dearth of storms is directly tied to El Niño and the way it creates strong winds in the upper atmosphere over the tropical Atlantic, which have a tendency to tear fledgling tropical storms and hurricanes apart before they can do damage. In addition, parts of the US can have warmer-than-average winters during El Niño years, lowering heating costs.

Of course, El Niño will still be bad news for other regions. At the same time as it’s prevented hurricanes from forming in the Atlantic, El Niño has led to a frenzy of hurricane activity in the eastern and central Pacific, with three storms impacting Hawaii in just one season.

Kelvin waves are a key player in contributing to the formation and maintenance of an El Niño event, but their effects are largely felt under the ocean’s surface, where they transport huge amounts of ocean heat from the western Pacific to the central and eastern Pacific.

“A Kelvin wave is not a tsunami or a wall of water,” said Dillon Amaya of North Carolina State University, who has been closely following Kelvin waves’ progress into California during this El Niño.

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After coming ashore in South America, such waves can then move north along the West Coast, where they can temporarily raise sea levels by 6 inches to a foot. But they do so slowly. If you were sitting on a beach looking at the water and a Kelvin wave were to lumber through, it’s unlikely that you’d even be able to see it.

“It’s an increase in the height of the nearest ~15 miles of water to the coast of 6-12 inches,” Amaya said. “Because that signal is so wide relative to the vertical change, it’s going to be hard for people to see in the same way they see a crashing wave.”

Kelvin waves are important not only for their role in heat transport, but because they make the coastline more vulnerable to flooding during astronomical high tides and winter storms.

The relationship between climate change and El Niño is a subject of active scientific research, with some studies showing that human-caused climate change could exacerbate the effects of El Niño events, and others coming to different conclusions.

One recent study did show that climate change is leading to stronger El Niño episodes , but that is viewed in the scientific community as a new finding that needs to be replicated via other studies before it is widely accepted.

At the same time, this super El Niño is occurring in a world in which the oceans are already record warm, adding heat on top of heat. El Niño events release stored heat from the ocean and transfer some of it into the atmosphere, boosting global average air temperatures for one to two years on top of climate change trends.

For this reason, it is very likely that 2026 and especially 2027 will set records for the planet’s warmest years to date.

The bottom line is that El Niño is a naturally occurring phenomenon that takes place about every three to seven years, with a minority of these events becoming strong enough to earn the informal designation of a super El Niño.

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The National Oceanic and Atmospheric Administration puts far more emphasis on weekly to monthly El Niño data than daily information, because there is so much variability in the day-to-day sea surface temperatures in the Pacific.

But because of the increased availability of daily ocean temperature data, many scientists are communicating on social media via vibe-coded dashboards, with daily data, leading to some confusion about whether and when El Niño has exceeded a historical benchmark.

By our count, using the weekly numbers from NOAA’s new “Relative Oceanic Niño Index,” El Niño is on track to set an all-time intensity record in November or December, and is running at or just above record levels for this time of year.

Many people want to know how this El Niño will affect them, but we can’t tell you the time and place. El Niño is not a storm that hits at a particular location, but rather a long duration phenomenon that tilts the odds in favor of extreme weather and climate events for certain areas.

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随着破纪录的超级厄尔尼诺现象几乎已成定局，预测和研究厄尔尼诺现象的科学家们收到了来自媒体和公众的大量咨询。虽然人们似乎普遍了解“厄尔尼诺”一词的含义，但许多人仍然不明白厄尔尼诺现象会如何影响他们，以及它与极端天气事件之间的联系等等。

以下是气象学家和气候科学家向 CNN 汇报的关于厄尔尼诺现象的 6 个最令人困惑的问题。

科学家们经常讨论厄尔尼诺现象可能带来的后果，以至于人们很容易想当然地认为所有厄尔尼诺事件的影响都相同——例如，厄尔尼诺年意味着加州降雨量会增加。但实际上，每一次厄尔尼诺事件都是独一无二的。例如，2015年至2016年的超级厄尔尼诺现象并没有给加州带来过多的降雨，这与基于以往超级厄尔尼诺事件的预测截然相反。

厄尔尼诺现象具有特殊性的部分原因是，它们并非单独发生，而是与其他影响天气模式的因素相互作用，例如极地涡旋以及不同的海洋和大气天气和气候周期。

资深厄尔尼诺现象研究员迈克尔·麦克法登表示，厄尔尼诺现象有各种各样的形态和大小，“没有两次是完全相同的”。

他说：“气候系统存在着巨大的混乱。”

人们很容易将厄尔尼诺现象及其引发的极端天气事件视为全是坏消息。但有些地区却能从这种气候周期中受益。例如，今年的大西洋飓风季异常平静，迄今为止只形成了一个飓风（尽管不幸的是，它袭击了美国）。

为什么这次厄尔尼诺现象如此强烈

风暴稀少与厄尔尼诺现象直接相关，厄尔尼诺现象会在热带大西洋上空的高层大气中产生强风，这些强风往往会在热带风暴和飓风造成破坏之前就将其摧毁。此外，美国部分地区在厄尔尼诺年份的冬季气温可能高于平均水平，从而降低取暖成本。

当然，厄尔尼诺现象对其他地区来说仍然是坏消息。虽然它阻止了大西洋飓风的形成，但同时也导致东太平洋和中太平洋飓风活动异常活跃，仅一个飓风季就有三场风暴袭击了夏威夷。

开尔文波是促成厄尔尼诺现象形成和维持的关键因素，但其影响主要体现在海洋表面以下，在那里，它们将大量的海洋热量从西太平洋输送到中东太平洋。

“开尔文波不是海啸或水墙，”北卡罗来纳州立大学的狄龙·阿玛亚说道，他一直在密切关注厄尔尼诺现象期间开尔文波向加利福尼亚的推进情况。

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这种波浪登陆南美洲后，会沿着西海岸向北移动，并可能暂时使海平面上升6英寸到1英尺。但它们的移动速度非常缓慢。如果你坐在沙滩上看着海水，一股开尔文波缓缓袭来，你很可能根本看不到它。

阿玛亚说：“这相当于距离海岸线约15英里范围内的水位上升了6到12英寸。由于这种信号相对于垂直变化而言范围很广，人们很难像看到巨浪拍岸那样注意到它。”

开尔文波不仅在热量输送中发挥着重要作用，而且还会使海岸线在天文大潮和冬季风暴期间更容易遭受洪水侵袭。

气候变化与厄尔尼诺现象之间的关系是当前科学研究的热点，一些研究表明人为造成的气候变化可能会加剧厄尔尼诺现象的影响，而另一些研究则得出了不同的结论。

最近一项研究确实表明气候变化导致厄尔尼诺现象更加强烈，但科学界认为这是一项新发现，需要通过其他研究进行重复验证才能被广泛接受。

与此同时，此次超级厄尔尼诺现象发生在海洋温度已创历史新高的世界，进一步加剧了全球气温的升高。厄尔尼诺现象会释放海洋中储存的热量，并将其中的一部分转移到大气层，在气候变化趋势的基础上，使全球平均气温在一到两年内持续升高。

因此，2026 年，尤其是 2027 年，很可能创下地球有史以来最温暖年份的纪录。

归根结底，厄尔尼诺现象是一种自然发生的现象，大约每三到七年发生一次，其中少数事件强度足够大，可以被非正式地称为超级厄尔尼诺现象。

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美国国家海洋和大气管理局更重视每周到每月的厄尔尼诺数据，而不是每日信息，因为太平洋海面温度的每日变化非常大。

但由于每日海洋温度数据的可用性增加，许多科学家通过带有氛围编码的仪表板在社交媒体上进行交流，并提供每日数据，这导致人们对厄尔尼诺现象是否以及何时超过历史基准存在一些困惑。

根据我们利用美国国家海洋和大气管理局 (NOAA) 最新发布的“相对海洋尼诺指数”的每周数据统计，厄尔尼诺现象有望在 11 月或 12 月创下历史最高强度纪录，并且目前正处于或略高于往年同期最高水平。

许多人都想知道这次厄尔尼诺现象会如何影响他们，但我们无法告知具体的时间和地点。厄尔尼诺现象并非袭击特定地点的风暴，而是一种持续时间较长的自然现象，它会增加某些地区发生极端天气和气候事件的概率。