The jet stream may be starting to shift in response to climate change

3 comments

1. Sections of the planet’s jet streams have begun shifting towards the poles over the past several decades. This is most likely a response to global warming due to our greenhouse gas emissions, and could exacerbate heat and drought in regions that depend on the high-altitude winds to steer storms their way.

   Jet streams are bands of fast-moving winds high in the atmosphere that blow from west to east around the mid-latitudes and the poles. This is sometimes referred to as “the jet stream”, but there are separate jet streams in each hemisphere and at different latitudes and altitudes. These winds occur due to the Earth’s rotation as well as the difference in temperature between the tropics and higher latitudes.

   Climate models have long anticipated that global warming would cause the position of the jet streams in each hemisphere to shift towards their respective poles. This is expected to occur as increasing heat in the tropics pushes the storms that fuel the jet streams further from the equator. But the short satellite record of global winds has made it challenging to know if the position of the jet streams was changing with any clear trend.

   That record, which begins around 1980, has only recently become long enough to begin reliably detecting a pattern, says [Thomas Keel](https://profiles.ucl.ac.uk/79418-tom-keel) at University College London. “It looks like it’s happening now – it has emerged from the noise,” he says.

   He and his colleagues analysed the jet stream above the north Pacific Ocean using several datasets on wind speed in the region spanning 1980 to 2022. They found that the average position of the North Pacific Jet Stream between December and February has seen a statistically significant shift northward of around 30 to 80 kilometres per decade. Keel says the short record means it remains unclear whether this shift is [greater than past variability](https://www.newscientist.com/article/2289897-shifting-jet-stream-due-to-warming-could-threaten-europe-from-2060/). But using climate models, the researchers project that this shift will continue in coming decades, expanding to other months by the end of the century under a high emissions scenario.

2. [Behind the paywall.](https://archive.ph/f1WtG)

3. Hmm, that seems less than ideal.