Posted on March 27, 2015 by Bob Berwyn
Findings from Swiss-American team present nuanced view of how climate change affects weather extremes
One of this past winter’s northeastern snowstorms swirls off the coast of New England in the satellite image via NASA Earth Observatory.
FRISCO — Adding more fuel to the debate over climate change and extreme weather, Swiss and American scientists this week said their new study shows that global warming tends to reduce temperature variability.
The cold and snowy weather that gripped much of the eastern U.S. this winter was probably not linked to Arctic amplification and increased waviness of the jet stream, according to the scientists with ETH Zurich and the California Institute of Technology.
Changes in the north-south difference in temperatures play a greater role in modifying temperature variability than changes in the jet stream, the researchers said. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: climate change, extreme weather, global warming, Jet stream | 2 Comments »
Posted on December 16, 2014 by Bob Berwyn
Is melting sea ice shifting the jet stream?
Study finds robust link between Arctic ice decline and severe Eurasian winter weather
FRISCO — If you feel like you’ve been on a weather roller coaster, maybe it’s because the jet stream has been behaving like one more and more often in recent years.
Instead of flowing around the mid-latitudes of the northern hemisphere with a few ripples, some years, the high-altitude river of air has been more like a writhing, out-of-control fire hose, snaking and looping, carrying huge surges of warm air north and cold. polar air south. At times, the jet stream has been getting stuck in that pattern for longer stretches. Continue reading
Filed under: Arctic, climate and weather, extreme weather, global warming | Tagged: Eurasian winter, extreme weather, global warming, Jet stream | 1 Comment »
Posted on August 26, 2014 by Bob Berwyn
An extratropical cyclone spread heavy rain across the UK in February 2014. Visit this NASA website for more.
More coastal damage likely as rising seas fuel storm surges
FRISCO —British scientists aren’t quite ready to say that last winter’s record flooding is linked with human-caused global warming, but in a recent study published in the journal Nature Climate Change, they warned that more coastal flooding is likely as sea level rises. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: Arctic sea ice, climate attribution studies, climate change, global warming, Jet stream, UK 2014 flooding | Leave a comment »
Posted on April 22, 2014 by Bob Berwyn
A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.
New study traces historic changes in North American weather patterns
By Bob Berwyn
FRISCO — A new University of Utah-led study suggests that this past winter’s persistent weather pattern across North America is linked with changes in the jet stream that may become even more pronounced as the Earth’s climate warms.
“If this trend continues, it could contribute to more extreme winter weather events in North America, as experienced this year with warm conditions in California and Alaska and intrusion of cold Arctic air across the eastern USA,” said geochemist Gabe Bowen, senior author of the study. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: climate, extreme weather, global warming, Jet stream | 1 Comment »
Posted on October 29, 2013 by Bob Berwyn
Changes in the Arctic likely to have widespread hemispheric impacts
By Summit Voice
FRISCO — A new climate study by scientists at the University of Exeter (UK) adds to the growing body of research looking at the hemispheric impacts of dwinding Arctic sea ice.
The findings suggest that that the loss of ice shifts the jet stream farther south, bringing increased summer rainfall to northwestern Europe, but drier conditions to the Mediterranean region. The study could offer an explanation for the extraordinary run of wet summers experienced by Britain and northwest Europe between 2007 and 2012.
In another recent study, scientists with the Cooperative Institute for Research in Environmental Science found that as sea ice disappeared, the areas of relatively warm open water began to strongly influence the atmosphere, increasing surface temperatures in the region, and shifting low- and high-pressure zones around most markedly in the fall and winter.
And a NOAA study found Arctic warming has shifted the normal west-to-east flowing upper-level winds to a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: Arctic sea ice, extreme weather, global warming impacts, Jet stream | 1 Comment »
Posted on June 25, 2013 by Bob Berwyn
A NASA satellite captured this clear-sky image of Alaska on June 17, as parts of the state saw record-high temperatures. Photo courtesy NASA/Jeff Schmaltz, LANCE MODIS Rapid Response Team, NASA GSFC. Click here to learn more about this image at the NASA Earth Observatory home page.
Maybe not, but it’s part of a pattern of more frequent climate extremes
By Bob Berwyn
FRISCO — A recent heat wave in Alaska has triggered yet another pointless debate about whether the record-breaking temperatures at some weather stations is a sign of global warming.
One of the best examples of how many journalists are missing the point came in the usually sharp-edged Alaska Dispatch in a story titled Why Alaska’s heat wave is a bad example of global warming.
After reciting a list of temperature statistics, downplaying wildfires and making critiques of other blog posts, the author ends with this assertion: “Moderation, it would seem, is the key to accurately representing data and making an informed decision on climate change.”
It’s not even remotely clear what is meant by moderation, but the reference to data is even more puzzling, considering that every credible temperature record from the past 50 years shows an inexorable rise in global temperatures — that’s why it’s called GLOBAL warming, regardless of what year-to-year, or decade-to-decade cycles may have been observed in Alaska. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: climate change, extreme weather, global warming, Jet stream, record heat alaska | 4 Comments »
Posted on June 10, 2013 by Bob Berwyn
German researchers cite ‘frozen’ jet stream waves as possible sign of climate change
By Summit Voice
FRISCO — Ten days of weather that included the largest tornado ever measured and some of the worst flooding Europe has ever seen are sure to rekindle the heated debate about possible links between global warming and extreme weather.
And despite the countless statistical arguments suggesting there has been no overall increase in extreme weather events, some scientists are becoming more willing to make the link, including researchers with the Potsdam Institute for Climate Impact Research.
In an interview with a regional German newspaper, the director of the research group referenced recent research that suggests the jet stream may be slowing down, wavering farther north and south and, at times, getting “stuck.” During May, a series of cyclonic storms traveled along this frozen jet stream wave, bringing seemingly endless rain and widespread flooding, said Hans Joachim Schellnhuber. Continue reading
Filed under: climate and weather, global warming | Tagged: climate change, European floods 2013, extreme weather, global warming, Jet stream | 1 Comment »