Could US winter storms be linked to global warming?

2 years ago 3 min read

Unlike the relationship between global warming and heat waves, which is a very direct relationship, The behavior of winter storms is governed by complex atmospheric dynamics that are difficult to study.

even so, “There are certain aspects of winter storms (…) where the links to climate change are quite clear”Michael Mann, a climatologist atUniversity of Pennsylvania .

for example, Increase in the temperature of water bodieslike lakes or oceans, It affects the amount of snow that falls.

in a United State the “Snowfall Lake Effect” Talk around the Great Lakes region, on the border with Canada. Buffalo is located on the shores of one of the Great Lakes. I had a really heavy snowstorm over the weekend birthday.

The clash between the cold air coming from the north with The warmer waters in these lakes cause convection, which leads to snowfall.

The higher the lake temperaturesmore moisture (there is) in the air and Increased probability of lake effect snowfallMann wrote in a 2018 article.

“As expected, We are seeing a long-term increase in lake-effect snowfall as temperatures rise over the past century“, It is to explain.

The polar vortex

However, there is no consensus regarding other mechanisms, Such as the effect of climate change on the polar vortex and jet streams.

The polar vortex is an air mass over the Arctic that lies in the upper stratosphere. Humans live in the troposphere, and the stratosphere is located just above it.

This vortex is surrounded by a rotating band of air, It acts as a buffer between the cooler air from the north and the warmer air from the south. When the polar vortex weakens, this bundle of air begins to ripple and It takes on a more elliptical shape, which brings more cold air to the south.

According to a 2021 study, This type of disorder occurs frequently And when that happens, It reverberates for the next two weeks in the atmospherewhere the jet stream is located.

This air current that blows from west to east, Again following the boundary between cold and warm airand then zigzag that way Cool air from the north is allowed to descend to lower latitudesparticularly in the eastern region United State .

“Everyone agrees that when the polar vortex is disturbed, Increases the likelihood of severe winter weatherJudah Cohen, lead author of the study and a climate scientist at the Center for Analysis of Atmospheric and Environmental Research (AER), told AFP.

And this “expanding” polar vortex is exactly what has been observed This is before the storm hit the US Dec, pointed out.

The same phenomenon was observed in February 2021, When a severe cold snap hit Texas it caused massive power outages.

Ongoing discussion

But the focus of the discussion revolves around a major question: What is causing this increasing disturbance in the polar vortex?

According to Cohen, These changes are associated with changes in the Arctic, which have been accelerated by climate change. in terms of fasting The melting of sea ice and, on the other hand, the increase in snow cover in Siberia.

“This is a topic I have been studying for over 15 years and today I am more sure than ever of this link.”He told AFP.

However, this last point remains An “ongoing debate” within the scientific community.

Climate models still don’t capture all of the underlying physics It may be related to how the climate is changing affect the behavior of the jet stream.Flour.

So, More studies will be needed in the coming years To unravel the mystery of these complex chain reactions.