While most of the rest of the world is feeling unusually warm, much of the United States is shivering in bitter cold. As strange as it may sound, scientists say the contradiction fits perfectly into explaining how climate change is affecting the planet.
Maps of global temperatures over the past few days show large parts of the world, including the North Pole, Asia, parts of Africa, the Middle East, and South America, in deep red, with temperatures exceeding 10 degrees Fahrenheit (7 degrees Celsius) or higher. is showing. Warmer than average for the second half of the 20th century.
But America stands out like a cold sore thumb, a deep blue-purple color that is equally insane but on the frigid side.
Wind chills in parts of North Dakota reached minus 70 degrees (minus 56 degrees Celsius), while Miami's heat index was more than 160 degrees warmer at 92 degrees (33 degrees Celsius). The fourth coldest NFL football game was played in Kansas City, while thermometers around the world hit 92 degrees, 12 degrees (6.8 degrees Celsius) above average, during tennis' Australian Open in Melbourne on Friday. was recorded. Temperature records fell overnight in Aruba, Curaçao, parts of Argentina, Oman and Iran.
In regions where the weather was warmer than usual, it occurred in both the southern hemisphere (summer) and the northern hemisphere (winter). For example, in northern Oman, the night temperature in January was the warmest on record at 79.5 degrees Celsius (26.4 degrees Celsius). In southern Argentina, the warmest January night on record was 81.1 degrees Fahrenheit (27.3 degrees Celsius).
It may seem as if the world is in turmoil, and in a sense it is. Because this all comes from what's happening in the Arctic, which was once warming twice as fast as the rest of the planet. Currently, global warming is progressing three to four times faster.
“If the Arctic is unusually warm…then there's a greater chance that extreme cold will hit places like Texas that aren't equipped to deal with extreme cold,” said Woodwell Research Center climate scientist and climate change expert. says pioneer Jennifer Francis. The “Arctic amplification theory'' links the cold epidemic and climate change. “Rapid warming of the Arctic is one of the most obvious symptoms of anthropogenic climate change, making extreme winters more likely to occur even as the planet as a whole warms.”
The intrusion of cold weather comes through a meteorological term increasingly familiar to Americans: the polar vortex. This is a meteorological term that dates back to 1853, but has only become more frequently used in the last decade.
Judah Cohen, a winter weather expert at Atmospheric Quality Research, a for-profit company outside Boston, said that may be because ice bites are occurring more frequently.
Cohen said a polar vortex is a strong, icy piece of weather that usually stays at the top of the Earth, trapped by strong winds that sweep around it.
He said it's like a figure skater spinning around at high speed with his arms tied tightly. But when the polar vortex weakens, the arms begin to flap, the skater slips, and “all the cold air is expelled from the center of the polar vortex,” Cohen said.
The current cold wave outbreak coincides with changes in the Arctic and the polar vortex, Cohen said. “What we've found is that when the polar vortex stretches out like a rubber band, there's a very good chance of severe extreme weather in the United States. That tends to be the focus, and in January We are seeing extreme examples of the polar vortex stretching.”
This polar vortex could be more powerful and last longer than other polar vortices, Cohen said.
look: Deadly Arctic freeze continues to hit the US, stranding travelers and causing power outages
Cohen and his colleagues conducted research showing that polar vortices have become more frequent in recent decades.
The idea is that the jet stream, the circulation of upper air that drives weather, is rippling with amplified global warming, said Steve Vavras, a climate scientist at the University of Wisconsin-Madison. These wave changes in the sky then knock the polar vortex away from its location and toward the United States, Cohen said.
This is a theory that is still being debated among climate scientists, but is gaining acceptance. Initially, Vavrus and Francis theorized that melting Arctic sea ice was causing changes in atmospheric pressure. Several scientists now believe that the picture is more complex, but still linked to climate change and excessive warming of the Arctic, and that other factors such as Siberian snowpack and other atmospheric waves also play a role. It states that
“The key takeaway for me at this point is that Arctic amplification is occurring and has complex interactions within the climate system.
“Winter always brings cold weather, but like warmer weather, the way we understand and are still learning may be changing,” said Marshall Shepard, professor of meteorology at the University of Georgia. . “Contrary to the Las Vegas slogan, what happens at the North Pole doesn’t stay at the North Pole.”
Think about what happens when an orchestra plays a symphony. “What's driving all these orchestral instruments is global warming,” said Victor Gensini, professor of meteorology at the University of Illinois at Northern.
Gensini and Cohen said the cold snap in the United States will subside in a few days, giving way to unusually warm weather due to climate change. However, it looks like another polar vortex will arrive later this month, but it won't be as strong as this one.
Despite the cold temperatures in the United States, Earth's global average temperatures continue to set daily, weekly, and monthly records for more than seven months. Scientists say this is because the United States covers only 2% of the Earth's surface.
“Places like Chicago, Denver, Lincoln, Omaha, Oklahoma City, Dallas, Houston, I mean we're all experiencing it,” Gensini said, adding that the temperature outside her window on Tuesday was He said it was 6 degrees colder. “Globally, we are just one isolated pocket.”