Latest news with #JudahCohen
Time of India
21-07-2025
- Science
- Time of India
US facing ice age? Polar vortex changes sending Northern Hemisphere into deep freeze
A new study links cold snaps in North America to changes in the polar vortex. The vortex, a low-pressure zone over the Arctic, is being disturbed by rising Arctic temperatures. This sends cold air southward. Researchers analyzed satellite data and weather records from 1980 to 2021. They found specific patterns in the stratosphere linked to cold weather in the U.S. Tired of too many ads? Remove Ads Tired of too many ads? Remove Ads How polar vortex cause cold snaps How stratospheric patterns steer cold air In today's times, when experts, scientists, and leaders across the globe are contemplating ways to tackle the simmering issue of global warming amid rising temperatures, winters in the Northern Hemisphere are still marked by cold snaps and extreme snowfall events. The Northern Hemisphere often sees snowfall events to some extent, such as the 2021 deep freeze in Texas and Oklahoma that caused over $1 billion in damage.A new study has surfaced that suggests these cold extremes are due to a rising common pattern in the polar vortex . According to it is the zone of low pressure that usually circulates over the Arctic. When this vortex gets disturbed, it changes shape and sends cold air into Canada and the U.S. This is happening more often because the Arctic is getting warmer."Overwhelmingly, extreme cold and severe winter weather, heavy snowstorms, and deep snow are associated with these stretched events," study co-author Judah Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research and a visiting scientist at MIT, told Live study carried out by Cohen and his team looked at how these events evolve in the stratosphere, the middle layer of the atmosphere that starts about 12 miles (19 kilometers) up. Understanding how these patterns shift could help meteorologists make longer-range forecasts, said Andrea Lopez Lang, an atmospheric scientist at the University of Wisconsin, Madison, who was not involved in the research."Knowing this information is useful for a lot of applications in energy and applications in insurance or reinsurance," Lang told Live Science. "How cold is it going to get? Are pipes going to burst? Are insurance claims going to spike this winter?" she polar vortex quite often circulates the North Pole like a spinning top, and occasionally, it collapses dramatically. This usually leads to polar air rushing toward northern Europe and Asia. These collapses can sometimes cause cold snaps in North America , but not always. "There's been this big question mark over what happens in North America," Lang and his team studied satellite data on the stratosphere and winter weather records from 1980 to 2021. They discovered that, short of total collapse, the polar vortex often wobbles and stretches, like a figure skater flinging out an arm for balance in a tricky spin. The researchers reported in the journal Science Advances that there were five different common patterns in the stratosphere, and two in particular were connected to cold weather dipping into Canada and the U.S. during these stretch events. Stretch events are increasing in general, Cohen said, but there has also been a shift in the type of stratospheric pattern usually brings cold air to the East Coast, while another chills the Midwest and Plains. Since 2015, researchers have noticed the westerly pattern happens more often. It's not clear why, but this change seems linked to La Niña, a pattern of unusually cold temperatures in the equatorial Pacific Ocean. In the last couple of decades, there have been multiple multiyear La Niña events. In the past twenty years, there have been several La Niña events that lasted for more than one researchers were able to detect some regularities in the way the polar vortex shifts between the five patterns, which might help improve forecasts over the two- to six-week period, Cohen said. "In that shorter range is the poorest accuracy," he said. "This paper can be helpful in that timeframe." One big question is how these polar vortex trends might change over time as the globe warms, Lang and his team have been looking at that question as well. The polar vortex is controlled by waves in the atmosphere, he said, and right now the most influential standing wave is over Eurasia, with a warm ridge to the west and a cooler trough to the east, which in turn is driven by patterns of warming in the melting sea ice is contributing to the increase in the temperature differences between the west and the east, strengthening the wave that can disrupt the vortex, Cohen said. If the sea ice disappeared, the pattern might collapse and flip. Instead of surprisingly cold winter events despite overall global warming, winter might suddenly become much toastier. "We could become more like the Southern Hemisphere, where you rarely get a breakdown of the polar vortex," Cohen said, "and it would probably mean warmer midlatitudes and a colder Arctic."
Yahoo
19-07-2025
- Climate
- Yahoo
Scientists discover changes to the polar vortex that are plunging parts of US into deep freeze
When you buy through links on our articles, Future and its syndication partners may earn a commission. Though global temperatures are warming, winters in the Northern Hemisphere are still marked by cold snaps and extreme snowfall events — sometimes to an unprecedented extent, such as the 2021 deep freeze in Texas and Oklahoma that caused over $1 billion in damage. Now, a new study suggests that these cold extremes are due to an increasingly common pattern in the polar vortex, the zone of low pressure that usually circulates over the Arctic. Disruptions to this vortex cause it to deform and stretch, spewing cold air into Canada and the U.S. These disruptions are becoming more common as the Arctic warms. "Overwhelmingly, extreme cold and severe winter weather, heavy snowstorms and deep snow, are associated with these stretched events," study co-author Judah Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research and a visiting scientist at MIT, told Live Science. Cohen and his team looked at how these events evolve in the stratosphere, the middle layer of the atmosphere that starts about 12 miles (19 kilometers) up. Understanding how these patterns shift could help meteorologists make longer-range forecasts, said Andrea Lopez Lang, an atmospheric scientist at the University of Wisconsin—Madison who was not involved in the research. "Knowing this information is useful for a lot of applications in energy [and] applications in insurance or reinsurance," Lang told Live Science. "How cold is it going to get? Are pipes going to burst? Are insurance claims going to spike this winter?" Usually, the polar vortex circulates around the North Pole like a spinning top. Occasionally, it collapses dramatically, which usually leads to polar air rushing toward northern Europe and Asia. These collapses can sometimes cause cold snaps in North America — but not always. "There's been this big question mark over what happens in North America," Lang said. Related: US suffers record-breaking cold: What's going on with the polar vortex? Cohen and his colleagues looked at stratosphere data from satellite observations between 1980 and 2021, as well as winter weather records from the same period. They found that, short of total collapse, the polar vortex often wobbles and stretches, like a figure skater flinging out an arm for balance in a tricky spin. There were five different common patterns in the stratosphere, the researchers reported in the journal Science Advances on July 11, and two in particular were linked to cold weather dipping into Canada and the U.S. during these stretch events. Stretch events are increasing in general, Cohen said, but there has also been a shift in the type of stretches. One of the stratospheric patterns tends to bring cold air toward the East Coast, while the other creates a chill in the Midwest and Plains region. Since 2015, the researchers found, the westerly pattern has been more common. It's not entirely clear why, but this shift seems to be associated with La Niña, a pattern of unusually cold temperatures to the equatorial Pacific Ocean. In the last couple of decades, there have been multiple multiyear La Niña events. The researchers were able to detect some regularities in the way the polar vortex shifts between the five patterns, which might help improve forecasts over the two- to six-week period, Cohen said. "In that shorter range is the poorest accuracy," he said. "This paper can be helpful in that timeframe." RELATED STORIES —La Niña is dead — what that means for this year's hurricanes and weather —Can cold weather make you sick? —Antarctic sea ice collapse linked to a mysterious spike in ocean salt One big question is how these polar vortex trends might change over time as the globe warms, Lang said. Cohen and his team have been looking at that question as well. The polar vortex is controlled by waves in the atmosphere, he said, and right now the most influential standing waves is over Eurasia, with a warm ridge to the west and a cooler trough to the east, which in turn is driven by patterns of warming in the Arctic. Currently, melting sea ice is increasing the temperature differences between west and east, strengthening the wave that can disrupt the vortex, Cohen said. If the sea ice disappeared, the pattern might collapse and flip. Instead of surprisingly cold winter events despite overall global warming, winter might suddenly become much toastier. "We could become more like the Southern Hemisphere where you rarely get a breakdown of the polar vortex," Cohen said, "and it would probably mean warmer midlatitudes and a colder Arctic."
Yahoo
14-02-2025
- Climate
- Yahoo
Very cold weather is coming. US about to get 10th and chilliest polar vortex this winter
The coldest burst of Arctic air this season is coming to put an icy exclamation point on America's winter of repeated polar vortex invasions, meteorologists warn. And it will stay frozen there all next week. Different weather forces in the Arctic are combining to push the chilly air that usually stays near the North Pole not just into the United States, but also Europe, several meteorologists tell The Associated Press. This will be the 10th time this winter that the polar vortex — which keeps the coldest of Arctic air penned in at the top of the world — stretches like a rubber band to send some of that big chill south, said Judah Cohen, seasonal forecast director at the private firm Atmospheric and Environmental Research. In a normal winter, it happens maybe two or three times. This winter, with record snow in New Orleans and drought and destructive wildfires in Southern California, has not been normal. The latest projected cold outbreak should first hit the northern Rockies and northern Plains Saturday and then stick around all next week. The cold will likely concentrate east of the Rockies with only the far American west and central and southern Florida exempted, meteorologists said. On Tuesday, expect the Lower 48 states to have an average low of 16.6 degrees Fahrenheit (minus 8.6 Celsius), and then plunge to 14 degrees (minus 10 Celsius) on Wednesday, calculated private meteorologist Ryan Maue, a former National Oceanic and Atmospheric Administration chief scientist. Sometime next week, 89% of the contiguous United States will be below the freezing mark and 27% of the Lower 48 will be below zero (minus 18 degrees Celsius), according to National Weather Service forecasts. Meteorologists expect strong winds to make the cold feel even worse. Every U.S. state but Hawaii, California and Florida have some or all parts forecast to have a good chance of windchills of 20 degrees or below sometime next week, the National Weather Service predicted. Kansas, Nebraska, Missouri and Iowa will have 'probably the most impressive' cold, with temperatures as much as 35 degrees (19 degrees Celsius) below what's normal for this time of year, said Zack Taylor, a meteorologist at the weather service's Weather Prediction Center. NOAA weather models predict Wednesday lows below zero in Oklahoma, Colorado, Nebraska, Missouri, Illinois, Iowa, Kansas, Wyoming, Montana, North Dakota, South Dakota, Minnesota, Wisconsin and Michigan. Some storms — with flooding, heavy snow or even a nor'easter — could hit during next week's prolonged cold outbreak, but details on those aren't certain yet, Taylor said. 'Everything, all the stars align, all the wind directions in the atmosphere are dragging the cold polar air out of the Canadian Arctic,' Maue said. 'It's the depths of winter. Everything signals extreme biting, winter cold. Obviously this isn't the first polar vortex episode of the winter, but it looks to be the most severe.' A stretched polar vortex like this one happens lower in the atmosphere and is different than when the polar vortex has sudden warming, weakens and all the cold air escapes south and out of the poles, Cohen said. During stretching events, the polar vortex remains in place and strong, but it also just pulls and bends. Stretch outbreaks are usually slightly milder than the big polar escape events and often hit the United States, not Europe. Meteorologists are going to want to study why this stretching is happening so often this year, but it could just be natural randomness, said Laura Ciasto, a meteorologist at NOAA's Climate Prediction Center who specializes in the polar vortex. 'What we're observing right now is interesting, but not unprecedented,' said Martin Stendel, a scientist at the National Center for Climate Research in Denmark. Another factor adding to the polar vortex stretching is a big blob of high pressure in the upper atmosphere over Greenland. It's moving west and will push the jet stream — the river of air that moves weather systems such as storms — into a pattern that causes polar air to plunge and stay there, Cohen said. Human-caused climate change may be making the jet stream wavier and more likely to be stuck in that wavy pattern, one of the factors involved, Stendel said. There haven't been many winters like this in the past to help meteorologists forecast what will happen next and when the cold will finally go away, Maue said. Despite the unusually cold winter across the U.S., the world remains in an overall warming pattern. Earth's average overall temperature set yet another monthly heat record in January. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.5 C (2.7 F) above pre-industrial times. ___ Data journalist Mary Katherine Wildeman contributed. ___ Follow Seth Borenstein on X at @borenbears ___ Read more of AP's climate coverage at ___ The Associated Press' climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP's standards for working with philanthropies, a list of supporters and funded coverage areas at Seth Borenstein, The Associated Press
Asharq Al-Awsat
14-02-2025
- Climate
- Asharq Al-Awsat
US about to Get 10th and Chilliest Polar Vortex This Winter
The coldest burst of Arctic air this season is coming to put an icy exclamation point on America's winter of repeated polar vortex invasions, meteorologists warn. And it will stay frozen there all next week. Different weather forces in the Arctic are combining to push the chilly air that usually stays near the North Pole not just into the United States, but also Europe, several meteorologists tell The Associated Press. This will be the 10th time this winter that the polar vortex — which keeps the coldest of Arctic air penned in at the top of the world — stretches like a rubber band to send some of that big chill south, said Judah Cohen, seasonal forecast director at the private firm Atmospheric and Environmental Research. In a normal winter, it happens maybe two or three times. This winter, with record snow in New Orleans and drought and destructive wildfires in Southern California, has not been normal. The latest projected cold outbreak should first hit the northern Rockies and northern Plains Saturday and then stick around all next week. The cold will likely concentrate east of the Rockies with only the far American west and central and southern Florida exempted, meteorologists said. On Tuesday, expect the Lower 48 states to have an average low of 16.6 degrees Fahrenheit (minus 8.6 Celsius), and then plunge to 14 degrees (minus 10 Celsius) on Wednesday, calculated private meteorologist Ryan Maue, a former National Oceanic and Atmospheric Administration chief scientist. Sometime next week, 89% of the contiguous United States will be below the freezing mark and 27% of the Lower 48 will be below zero (minus 18 degrees Celsius), according to National Weather Service forecasts. Meteorologists expect strong winds to make the cold feel even worse. Every US state but Hawaii, California and Florida have some or all parts forecast to have a good chance of windchills of 20 degrees or below sometime next week, the National Weather Service predicted. Kansas, Nebraska, Missouri and Iowa will have "probably the most impressive" cold, with temperatures as much as 35 degrees (19 degrees Celsius) below what's normal for this time of year, said Zack Taylor, a meteorologist at the weather service's Weather Prediction Center. NOAA weather models predict Wednesday lows below zero in Oklahoma, Colorado, Nebraska, Missouri, Illinois, Iowa, Kansas, Wyoming, Montana, North Dakota, South Dakota, Minnesota, Wisconsin and Michigan. Some storms — with flooding, heavy snow or even a nor'easter — could hit during next week's prolonged cold outbreak, but details on those aren't certain yet, Taylor said. "Everything, all the stars align, all the wind directions in the atmosphere are dragging the cold polar air out of the Canadian Arctic," Maue said. "It's the depths of winter. Everything signals extreme biting, winter cold. Obviously, this isn't the first polar vortex episode of the winter, but it looks to be the most severe." A stretched polar vortex like this one happens lower in the atmosphere and is different than when the polar vortex has sudden warming, weakens and all the cold air escapes south and out of the poles, Cohen said. During stretching events, the polar vortex remains in place and strong, but it also just pulls and bends. Stretch outbreaks are usually slightly milder than the big polar escape events and often hit the United States, not Europe. Meteorologists are going to want to study why this stretching is happening so often this year, but it could just be natural randomness, said Laura Ciasto, a meteorologist at NOAA's Climate Prediction Center who specializes in the polar vortex. "What we're observing right now is interesting, but not unprecedented," said Martin Stendel, a scientist at the National Center for Climate Research in Denmark. Another factor adding to the polar vortex stretching is a big blob of high pressure in the upper atmosphere over Greenland. It's moving west and will push the jet stream — the river of air that moves weather systems such as storms — into a pattern that causes polar air to plunge and stay there, Cohen said. Human-caused climate change may be making the jet stream wavier and more likely to be stuck in that wavy pattern, one of the factors involved, Stendel said. There haven't been many winters like this in the past to help meteorologists forecast what will happen next and when the cold will finally go away, Maue said. Despite the unusually cold winter across the US, the world remains in an overall warming pattern. Earth's average overall temperature set yet another monthly heat record in January. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.5 C (2.7 F) above pre-industrial times.
Yahoo
14-02-2025
- Climate
- Yahoo
Very cold weather is coming. US about to get 10th and chilliest polar vortex this winter
The coldest burst of Arctic air this season is coming to put an icy exclamation point on America's winter of repeated polar vortex invasions, meteorologists warn. And it will stay frozen there all next week. Different weather forces in the Arctic are combining to push the chilly air that usually stays near the North Pole not just into the United States, but also Europe, several meteorologists tell The Associated Press. This will be the 10th time this winter that the polar vortex — which keeps the coldest of Arctic air penned in at the top of the world — stretches like a rubber band to send some of that big chill south, said Judah Cohen, seasonal forecast director at the private firm Atmospheric and Environmental Research. In a normal winter, it happens maybe two or three times. See for yourself — The Yodel is the go-to source for daily news, entertainment and feel-good stories. By signing up, you agree to our Terms and Privacy Policy. This winter, with record snow in New Orleans and drought and destructive wildfires in Southern California, has not been normal. The latest projected cold outbreak should first hit the northern Rockies and northern Plains Saturday and then stick around all next week. The cold will likely concentrate east of the Rockies with only the far American west and central and southern Florida exempted, meteorologists said. On Tuesday, expect the Lower 48 states to have an average low of 16.6 degrees Fahrenheit (minus 8.6 Celsius), and then plunge to 14 degrees (minus 10 Celsius) on Wednesday, calculated private meteorologist Ryan Maue, a former National Oceanic and Atmospheric Administration chief scientist. Meteorologists expect strong winds to make the cold feel even worse. Every U.S. state but Hawaii, California and Florida have some or all parts forecast to have a good chance of windchills of 20 degrees or below sometime next week, the National Weather Service predicted. Kansas, Nebraska, Missouri and Iowa will have 'probably the most impressive' cold, with temperatures as much as 35 degrees (19 degrees Celsius) below what's normal for this time of year, said Zack Taylor, a meteorologist at the weather service's Weather Prediction Center. NOAA weather models predict Wednesday lows below zero in Oklahoma, Colorado, Nebraska, Missouri, Illinois, Iowa, Kansas, Wyoming, Montana, North Dakota, South Dakota, Minnesota, Wisconsin and Michigan. Some storms — with flooding, heavy snow or even a nor'easter — could hit during next week's prolonged cold outbreak, but details on those aren't certain yet, Taylor said. 'Everything, all the stars align, all the wind directions in the atmosphere are dragging the cold polar air out of the Canadian Arctic,' Maue said. 'It's the depths of winter. Everything signals extreme biting, winter cold. Obviously this isn't the first polar vortex episode of the winter, but it looks to be the most severe.' A stretched polar vortex like this one happens lower in the atmosphere and is different than when the polar vortex has sudden warming, weakens and all the cold air escapes south and out of the poles, Cohen said. During stretching events, the polar vortex remains in place and strong, but it also just pulls and bends. Stretch outbreaks are usually slightly milder than the big polar escape events and often hit the United States, not Europe. Meteorologists are going to want to study why this stretching is happening so often this year, but it could just be natural randomness, said Laura Ciasto, a meteorologist at NOAA's Climate Prediction Center who specializes in the polar vortex. 'What we're observing right now is interesting, but not unprecedented,' said Martin Stendel, a scientist at the National Center for Climate Research in Denmark. Another factor adding to the polar vortex stretching is a big blob of high pressure in the upper atmosphere over Greenland. It's moving west and will push the jet stream — the river of air that moves weather systems such as storms — into a pattern that causes polar air to plunge and stay there, Cohen said. Human-caused climate change may be making the jet stream wavier and more likely to be stuck in that wavy pattern, one of the factors involved, Stendel said. There haven't been many winters like this in the past to help meteorologists forecast what will happen next and when the cold will finally go away, Maue said. Despite the unusually cold winter across the U.S., the world remains in an overall warming pattern. Earth's average overall temperature set yet another monthly heat record in January. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.5 C (2.7 F) above pre-industrial times. ___ Read more of AP's climate coverage at ___ Follow Seth Borenstein on X at @borenbears _____ The Associated Press' climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP's standards for working with philanthropies, a list of supporters and funded coverage areas at
