Tag: Jet stream

Connecting the climate change dots

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Global warming is going to push the snow line uphill by as much as 1,400 feet in many western mountains. @bberwyn photo.

Pole to pole and across the world’s oceans and mountains, climate change impacts are adding up

By Bob Berwyn

For any Summit Voice readers not following my Twitter or Facebook feeds, here’s a list of links to my recent stories for InsideClimate News.

Of greatest interest here in the West is a new University of Utah study that projects a dramatic upward shift of the snowline in the Rockies and coastal ranges in California, Oregon and Washington. Less spring snowpack at lower elevations has huge effects on we manage our water, and could also result in more early season wildfires: Unabated Global Warming Threatens West’s Snowpack, Water Supply.

In mid-May I wrote about the latest update to NOAA’s annual greenhouse gas index, which showed that atmospheric CO2 concentration showed its biggest annual increase on record in the past year. The index also showed a surge in Methane, an etremely potent heat-trapping pollutant: Far From Turning a Corner, Global CO2 Emissions Still Accelerating. Continue reading “Connecting the climate change dots”

More evidence that melting Arctic ice drives widespread changes in northern hemisphere weather patterns

‘Blocking highs’ becoming more common over Greenland

greenland aerial view
What happens in Greenland doesn’t stay in Greenland. Climate shifts in the Arctic affect the rest of the northern hemisphere. @bberwyn photo.

Staff Report

Just a few weeks after scientists reported record early melting on parts of the Greenland Ice Sheet, a new study helps explain some of the recent dramatic climate shifts in the high latitudes of the northern hemisphere.

Stationary high pressure systems over Greenland have become more frequent since the 1980s, said University of Sheffield geographer Prof. Edward Hanna, adding that the pattern is also linked with extreme weather over northwest Europe, including unusually wet conditions in the UK in the summers of 2007 and 2012.

The study, published in the International Journal of Climatology, looked at large-scale weather patterns over Greenland going back to 1851 using a measure called the Greenland Blocking Index, which marks the how strong the high pressure systems are, how long they last and how often they occur. Continue reading “More evidence that melting Arctic ice drives widespread changes in northern hemisphere weather patterns”

Climate: Jet stream shifts may speed Greenland meltdown

More sea level woes ahead?

Melting on the surface of the Greenland Ice Sheet.
Melting on the surface of the Greenland Ice Sheet. @bberwyn photo.
How will global warming affect the flow of the jet stream?
How will global warming affect the flow of the jet stream?

Staff Report

Scientists are tracking yet another global warming feedback mechanism that will have dire consequences for coastal communities around the world. Melting sea ice and overall rapid warming in the Arctic are factors in the development of so-called blocking high pressure systems — air masses spinning clockwise that block cold, dry Canadian air from reaching Greenland.

The highs tend to enhance the flow of warm, moist air over Greenland, contributing to increased extreme heat events and surface ice melting, according to the study. That circulation pattern leads to more melting of the Greenland Ice Sheet, according to new research published online in the Journal of Climate last month, co-authored by Jennifer Francis, one of the pioneers in studying how global warming is affecting the jet stream. Continue reading “Climate: Jet stream shifts may speed Greenland meltdown”

Global warming: New NOAA study eyes link between Arctic meltdown and extreme weather in mid-latitudes

A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.
A warming Arctic is changing the configuration of the jet stream, which affects mid-latitude weather. GRAPHIC COURTESY NOAA.

‘Too soon to tell …’

Staff Report

*More Summit Voice stories on this subject are here

FRISCO — There’s been lots of speculation and some early research on a possible link between soaring temperatures in the Arctic and extreme weather in North America and Europe, but the jury is still out, according to scientists with the National Oceanic and Atmospheric Administration.

NOAA’s James Overland was part of an international team that took a close look at possible connections and concluded that more research is needed.

“We are in the pre-consensus stage of a theory that there are links between the rapid warming of the Arctic and some severe weather events since 2007,” said Overland, lead author of the new study, “The melting Arctic and Mid-latitude weather patterns: Are they connected?” Continue reading “Global warming: New NOAA study eyes link between Arctic meltdown and extreme weather in mid-latitudes”

Study: Global warming not to blame for fierce winter

Findings from Swiss-American team present nuanced view of how climate change affects weather extremes

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One of this past winter’s northeastern snowstorms swirls off the coast of New England in the satellite image via NASA Earth Observatory.

Staff Report

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 “Study: Global warming not to blame for fierce winter”

Is melting Arctic sea ice shifting the jet stream?

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Is melting sea ice shifting the jet stream?

Study finds robust link between Arctic ice decline and severe Eurasian winter weather

Staff Report

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 “Is melting Arctic sea ice shifting the jet stream?”

Climate: UK study eyes links between global warming, extreme flooding

An extratropical cyclone
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

Staff Report

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 “Climate: UK study eyes links between global warming, extreme flooding”