Because Europe doesn’t have the extreme cold that hits North America

It has been very cold for the past few days America hitAt least 57 people died as a result count NBC News, which is not unusual. Occasionally, during the winter, cold air sweeps across North America and brings blizzards: this happened in February 2021. In Texas The lowest temperature recorded in 30 years resulted in at least 250 deaths.

These weather events are associated with the Arctic vortex, a large area of ​​low pressure above the North Pole. It does not have the same effects in Europe due to the different geographical characteristics of the two continents: most of the Americas were below the seasonal average of recent decades, and in fact, Europe was colder than usual.

The U.S. is facing bitterly cold weather, but the rest of the world — including Europe and the Arctic — is unusually warm. Please heed all warnings and stay safe.

Note that even in the era of climate change, we will still see colder weather.https://t.co/5bCBRoHfWj pic.twitter.com/6NlmFbuOos

— World Meteorological Organization (@WMO) December 22, 2022

In Canada and the United States, last week’s weather was deeply affected by the extension of the Arctic vortex. Usually the vortex is “captured” by a jet stream over the extreme north, that is, a fast wind that is located south of the pole, blows from west to east and is warmer. The jet stream acts as a barrier to the Arctic vortex like the edge of a bowl: the cold air above the pole is smothered by this relatively warm air, creating a barrier of sorts. But as temperatures rise in the Arctic, a portion of cold air, slightly less cold, moves beyond the edge of the “bowl” and reaches the continental regions beyond the usual limits of the jet stream.

This air is warmer than normal for arctic climates, but it is also colder than continental temperatures and causes extreme weather events like the recent blizzard.

North America and Europe are at the same latitude (New York is the same as Naples). However, it is rare for both continents to be hit by cold waves at the same time, and these winter events in North America are very frequent and intense. The reasons for the differences are varied, Explained A few days ago Giulio Betti, National Research Council (CNR) Meteorologist and AMPRO, Association of Professional Meteorologists.

First, although Europe can also be affected by the polar vortex, the air that reaches it passes through the North Atlantic first rather than Canada: in general, air over land in winter is colder than over oceans. This is especially true in northern Europe due to the warm Gulf Stream, the main reason why northern European climates are milder than those of Canada and North America.

North American coasts, on the other hand, are subject to the influence of cold ocean currents. On the other hand, in addition to the Gulf Stream, Europe can also count The Mediterranean SeaAnother “reservoir” of heat.

– read more: Is the cold caused by the Arctic gyre affected by climate change?

Another reason North America is more exposed to cold air from the north has to do with the mountains. Stretching north and south from British Columbia in Canada to New Mexico in the US, the Rocky Mountains are no barrier to the northerly winds. Instead, they help guide the east.

In Europe, the main mountain range, the Alps, is instead oriented latitudinally and therefore acts as a barrier to cold air from the north, which contributes to Italy’s temperate climate. The Urals, the mountains that separate European Russia from Asian Russia, are long, but despite this, they play a role in helping to block the cold air: coming from Siberia, that is, the nearby big cold continent. However, this area is greater than the distance from Europe to northern Canada and the United States, so “it cannot always affect the weather conditions of the continent,” Petty explained.

Snow and cold in recent days have particularly affected Erie County in New York State, where the city of Buffalo is located: only there 27 people died, this number is feared to increase as half of them are outside. “Unfortunately we are still finding bodies,” he said On Monday, City Police Commissioner Joseph Gramaglia spoke about the relief efforts.

– read more: Even if it’s freezing, there is global warming