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Study shows link between melting arctic and U.S. wildfires

Climatologists have just identified a disturbing “butterfly effect” that directly links the melting ice in the Arctic to extreme weather events in the American West.

One of the aspects of climatology that makes this science so complicated to grasp is that the effects of a phenomenon are very far from its cause, both in time and in space. Very often, it takes fairly extensive studies to realize this; this is what happened with the work of a team of American researchers; they noticed a direct correlation between the fires in the west of the country and the ice floes in the arctic.

The invisible link that unites the climate of these two regions was already widely documented, but its origin remains unexplained for the moment. According to the team of climatologist Yufei Zou, these two regions are linked by a dynamic vaguely comparable to that of the famous ENSO phenomenon (El Nño – Southern Oscillation).

It’s not a perfect analogy”, Details the geologist and climatologist Hailong Wong. “But these kinds of connections are a bit like the butterfly effect. Climatic conditions on one side of the world can ultimately influence the climate for thousands of kilometers”’, He continues. “In our case, we have determined that the Arctic region and the western United States are connected by such a relationship. Local warming caused by melting ice triggers warming and drying out in the West later in the year”.

A detour on the windward highway

In addition to providing solid new evidence for this dynamic, the researchers have also unveiled the underlying phenomena that fuel it. They explain that as the air warms up due to the melting ice, the difference in atmospheric pressure generates a vortex over the area. This vortex then disrupts the course of the polar Jet Stream. A phenomenon far from negligible, knowing that this powerful draft is absolutely capital in the global climate dynamics.

This change of trajectory therefore has very concrete consequences, one of which is particularly important; he diverts the humid air that the Jet Stream typically carries in the Eastern United States. This situation then generates a second vortex, this time on American soil, and which turns the opposite direction with respect to the arctic vortex. And according to the researchers, it is this second inverted vortex that is directly responsible for certain extreme climatic phenomena. For example, they hold him responsible for the incredible heat wave that hit America in the summer of 2021. This would also have the effect of favoring the appearance of the numerous forest fires that ravage the region each year.

A very concerted example of a climate vicious circle

And this is particularly worrying, because it lays the foundations for a vicious circle from which it will be very difficult to extricate itself. Indeed, the researchers say that the sea ice has already regressed by about 13% since the beginning of the decade. At this rate, even the oldest of permafrost, these famous “eternal ice cream”, Could well experience periods of total melting from 2050.

However, as mentioned above, it is this melting ice that largely feeds this dynamic. The less ice there is, the less the Earth reflects the sun’s rays and the more energy it absorbs. It therefore heats up more, which tends to strengthen the vortex over the arctic. This therefore feeds the formation of the second vortex; the latter in turn triggers climatic phenomena such as fires, which can contribute to global warming … and therefore to the melting of ice. The circle has come full circle, and that’s not good news.

The trend is alarming and indisputable”, Explains Rick Spinrard, administrator of the American agency for the climate. “We are at a decisive moment. We absolutely must act”, He thunders. But rather than giving in to fatalism, researchers prefer to rejoice in this information; now, they have more cards in hand to hope to stem this phenomenon. It remains to be seen whether the political will will follow.

The research paper is available here.

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