Article: ‘Since observational measurements started, blocking in the Arctic has increased, as has Arctic warming.’ When researchers investigated ‘they found a stunning correlation’. No mention of greenhouse gases in the study.
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A team of scientists led by François Lapointe, a research associate at the University of Massachusetts Amherst, has combined paleoclimatic data from the last 2,000 years with powerful computer modeling and in-the-field research on lake sediments and tree rings to show that an understudied phenomenon, known as atmospheric blocking, has long influenced temperature swings in the Arctic.
As temperatures warm due to climate change, claims EurekAlert, atmospheric blocking will help drive ever-wilder weather events. [Talkshop comment – routine alarmist hype].
The study focused on the Norwegian Arctic archipelago, Svalbard, at the edge of the Arctic Ocean, and was published in Nature Communications.
It is well known that the Arctic is warming faster than the global average, a phenomenon known as Arctic Amplification. But, since 1991, Svalbard has experienced a warming trend that is double the Arctic-wide rise in temperature.
Consequently, the archipelago has been experiencing massive loss of ice, extreme rainfall events and landslides. “We wanted to know why Svalbard has been warming so much faster than the rest of the Arctic,” says Raymond Bradley, Distinguished Professor at UMass Amherst and co-author of the study, “and to figure out whether or not these trends would continue.”
To do so, they turned to lake sediments from Lake Linné, on the west coast of Svalbard, to help them reconstruct warm and wet conditions during the past 2,000 years.
What makes this lake unique is the presence of instruments that have been deployed since 2012 by UMass Amherst alumnus and co-author, Michael Retelle, currently professor of earth and climate sciences at Bates College. These instruments track the precise timing of sediment entering the lake each year. Sediment pours into the lake during the increasingly frequent freak rainstorms.
Lapointe and his team looked at the calcium levels in Lake Linné’s sediments. Because much of the eastern terrain surrounding the lake is composed of carbonate-rich soil, intense rain events mean that carbonate washes into the lake, settles into the sediment on the lake bottom, and can be measured in sediment cores as a record of rainfall stretching back approximately 2,000 years.
When Lapointe and his colleagues compared all these historic and contemporary observations to the meteorological record, they found a stunning correlation.
“The biggest rain and warming events of the past are all linked to atmospheric blocking over Scandinavia and the Ural Mountains. Atmospheric blocking is when a high-pressure system, with air rotating clockwise around it, stalls over a particular region—in this case northern Scandinavia. In tandem with this high-pressure system, rain events in Svalbard are also often associated with a low-pressure system that settles in over Greenland, which rotates counter-clockwise,” Lapointe says.
The two systems spin like a pair of intermeshed gears, drawing warmer, moister air up from the mid-Atlantic Ocean into the Arctic, leading to downpours of rain in Svalbard. Since observational measurements started, blocking in the Arctic has increased, as has Arctic warming.
Full article here.
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Image: Svalbard map [credit: theoceanadventure.com]
Tallbloke's Talkshop 
“…with powerful computer modeling…”
More Xbox “science”…
Yawn!
From the study:
Rainfall episodes lead to the deposition of coarse sediment particles and high levels of calcium in Linnévatnet, a lake in southwest Svalbard, with the coarsest sediments consistently deposited during atmospheric blocking events. A unique annually resolved sediment record from Linnévatnet confirms that this linkage has been persistent over the past 2000 years. Our record also shows that a millennial-scale decline in Svalbard precipitation ended around the middle of the 19th century, followed by several unprecedented extreme events in recent years.
The authors also say:
Several factors impede a comprehensive understanding of blocking episodes and their impacts: the insufficient length of instrumental data, the absence of proxies capable of describing blocking events before the advent of instrumental records, and the variable depiction of blocking in the current generation of climate models.
Now I wonder who is paying for all this rubbish?
[reply] see first sentence of blog post
This was written:
It is well known that the Arctic is warming faster than the global average, a phenomenon known as Arctic Amplification. But, since 1991, Svalbard has experienced a warming trend that is double the Arctic wide rise in temperature. Consequently, the archipelago has been experiencing massive loss of ice, extreme rainfall events and landslides. “We wanted to know why Svalbard has been warming so much faster than the rest of the Arctic,” says Raymond Bradley, Distinguished Professor at UMass Amherst and co-author of the study, “and to figure out whether or not these trends would continue.”
The sun powers evaporation and snowfall. Over the recent ten thousand years, the annual max solar in between 60 and 90 degrees north has decreased more than 35 watts per meter squared while the annual max solar in between 60 and 90 degrees south has increased that much.
The north used to be cooled more by ice because the more solar in powered the polar evaporation and snowfall. Now, more evaporation and snowfall happen between 60 and 90 in the southern hemisphere. With less sun in the north, there is less evaporation and snowfall and less ice sequestering. The places that have lost ice, where ice has retreated, have naturally warmed.
Ice does not advance because it got colder, and ice does not retreat because it got warmer. Ice core records show the warmest times have the most ice accumulations and it gets colder after that as more ice advances faster, coldest times have the least ice accumulations, and it gets warmer after that as less ice pushes the glaciers and spreads the ice sheets slower than the natural loss. The energy that is thawing ice around the arctic is brought in by warm tropical currents, solar in has decreased and there is less evaporation and snowfall and ice sequestering and less cooling by thawing and reflecting ice. This is not any kind of man-made disaster that man can stop, this is natural, long-term, internal, alternating, warmer and colder cycles, such as have always occurred. The Vikings moved to Greenland in a previous warm time, this is just as natural.
They wrote:
It is well known that the Arctic is warming faster than the global average, a phenomenon known as Arctic Amplification.
Yes, this is well documented in ice core records. There are warmer times with thawed sea and more snowfall and it always has changed quickly to colder at the end of warm periods. There are colder times with sea ice and less snowfall and it has always changed quickly to warmer at the end of colder times.
This was, or should have been expected, if history and ice core records were considered.
The Norwegian Polar Institute’s research found that 1,000 years ago the climate on Svalbard was mild, allowing the seas to be navigable. This warmer climate lasted until the 1200s. After this time the climate was in a cold period, or a mini ice age, apart from around the 1750s when the climate was warmer. Data from ice cores has found the 20th century was the warmest century in the last 600 years.
https://en.wikipedia.org/wiki/Climate_of_Svalbard#Historical_data
What caused the previous mild climate? Not trace gases…
Data from ice cores has found the 20th century was the warmest century in the last 600 years.
Yes, we just came out of the little ice age, the coldest ice age in ten thousand years and this is still the coldest warm time in ten thousand years as indicated by Greenland ice core records:
A thousand years ago in the Medieval warm period, it was warmer than now.
Two thousand years ago in the Roman warm period, it was warmer than now.
Even before that, there were alternating warmer and colder time periods.
In order to frighten most everyone, to tax and control most everyone, they take every natural happening and turn it into something that has not happened in their recorded history, which only goes back a couple hundred years.
Many times, I have heard some of the Climate People say, or they wrote:
All climate models are wrong, but they can be useful, they can tune the models to produce frighting output.
So rainfall declined over a long period then increased again. The increase is CO2 but the previous high that then declined was natural. And its CO2 because “unprecedented”.
Once again, good science corrupted by bad.
the absence of proxies capable of describing blocking events before the advent of instrumental records
They say ‘absence of proxies’ then claim ‘unprecedented’ blah blah, but they’ve just admitted there’s no way of proving that beyond the recent past [and see next comment].
Modelling Northern Hemisphere atmospheric blocking systems
06 Mar 2024 | From the CO2Science Archive
Davini and D’Andrea report that although “some models positively react to improved sea surface temperatures, others even deteriorate their blocking climatology.” And they thus conclude that “although the overall picture seems somewhat discouraging – with good improvements over the Pacific but negligible advancements over Euro-Atlantic blocking in 20 years – the modelling community appears to be moving on the right track.” And so, they conclude, “it is likely that the problem of blocking simulation in GCMs will be significantly alleviated in future years.” But when in the future that might occur, God only knows. [bold added]
https://climatediscussionnexus.com/2024/03/06/modelling-northern-hemisphere-atmospheric-blocking-systems/
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IPCC AR6: Atmospheric Blocking, Unspun Edition (2021)
Many climate models still underestimate the occurrence of blocking, at least in winter over northeastern Atlantic and Europe.
https://climatediscussionnexus.com/2021/12/15/ipcc-ar6-atmospheric-blocking-unspun-edition/