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Thursday, January 4, 2024

Dr Jennifer Francis on weather whiplash, 2024 and beyond "Expect surprises, destruction, suffering..."

New research has investigated abrupt swings in extreme weather in the Northern Hemisphere. This is being driven by Arctic amplified warming and slowing of the Northern Hemisphere Jet stream.

Changes to the Jet Stream is one of the areas that Dr Jennifer Francis has been focussed on. Francis is Senior Climate Scientist with the Woods Hole Institute in the US. Her recent research has been in weather whiplash, abrupt changes in extreme weather as it applies to North America and Europe.

This interview below is with Nick Breeze and she says for 2024 expect surprises, more broken weather records, and extreme weather will get even worse.


"As youlook forward to 2024 the scientists I have spoken to say its going to get worse. I mean from a European perspective, I'd say the last six months or so have been pretty bad. I mean we've seen some  horrific things in Europe this summer, and then flash flooding across Italy, Spain. All over the place basically. So I mean from this perspective it seemed pretty raw in terms of extreme events.

"We fully expect El Nino to continue to remain strong for at least a few months. That always tends to create some weather havoc of various sorts in various places. Ocean heatwaves are still raging out there. The Atlantic is still mostly very warm. The Arctic is very warm as well. We're expecting to see the polar strataspheric vortex undergo major disruption, probably in mid January or so and that always brings some severe weather conditions. Often brings cold down into Europe and Northern Asia, even Central Asia and eventually also to North America.

"So there are a lot of reasons to expect this crazy weather to continue in 2024.

"We are seeing the Earth on average is continuing to break records for the temperature globally, and especially the oceans. So we are in uncharted territory in terms of what the earth is doing, what the oceans are doing. These extreme events are certainly being exacerbated by that."

Francis called out the level of action is far too little, singly out the major countries actually expanding fossil fuel production: US, Canada, UK, Norway, Saudi Arabia, China, Russia and Australia. Pumping more greenhouse gases is amplifying Arctic warming which means weather whiplash will occurr more frequently and likely with greater intensity.

"They are literally doing the very thing that'll make all these problems worse. ... This is exactly the wrong direction. We need to stop investing in new fossil fuel infrastructure and phase out what is already in place."

On what to expect in 2024:

"I don't know if chaos is the right word. I would say surprises, expect surprises. Expect more broken records. Expect more unprecedented weather events. Expect more destruction, suffering. Very high costs to these destructive events. Worldwide we are spending billions of dollars recovering from these events and that is going up. I think the world hit a new record thia year on the amount of money spent on weather disasters. So this is what we need to remember and expect not just for 2024, but going forward its just going to get worse."


Francis co-authored new research published in Nature on 21 December 2023 titled: Weather whiplash events in Europe and North Atlantic assessed as continental-scale atmospheric regime shifts.

The Abstract says:

The term “weather whiplash” describes abrupt transitions from one persistent weather regime to another substantially different one, such as from a frigid cold spell to anomalous warmth. Weather whiplash events (WWEs) are often highly disruptive to agriculture, ecosystems, infrastructure, and human activities. While no consistent definition exists, we identify WWEs based on substantial shifts in the continental-scale, upper-atmosphere circulation. As first demonstrated in our earlier study focused on the NE Pacific/North American region, a WWE is detected when one persistent, large-scale pattern in 500 hPa height anomalies shifts to another distinctly different one. Patterns are identified using self-organizing maps (SOMs), which create a matrix of representative patterns in the data. In the present study, we apply this approach to identify WWEs in the North Atlantic/European sector. We analyze the occurrence of WWEs originating with long-duration events (four or more days) in each pattern. A WWE is detected when the pattern two days following a long-duration event is substantially different, measured with distance thresholds internal to the matrix. Changes in WWE frequency, past and future, are assessed objectively based on reanalysis output and climate model simulations. We find that future changes under RCP 8.5 forcing exhibit distinct trends, especially in summer months, while those based on reanalysis are less clear. Patterns featuring positive height anomalies in high latitudes are projected to produce more WWEs in the future, while patterns exhibiting negative anomalies produce fewer. Shifts in temperature and precipitation extremes associated with these WWEs are diagnosed.

I first came across the work of Francis over ten years ago. I published a blog on Arctic amplification, the Jet stream and Extreme weather in Northern Hemisphere (March 2013) which featured a Youtube interview with Francis. 


References

Francis, J.A., Skific, N. & Zobel, Z. Weather whiplash events in Europe and North Atlantic assessed as continental-scale atmospheric regime shifts. npj Clim Atmos Sci 6, 216 (2023). https://doi.org/10.1038/s41612-023-00542-9 

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