From DARTMOUTH COLLEGE and the “snowfalls are a thing of the past” department.
Unprecedented findings strengthen connections between winter storms and tropical waters
HANOVER, N.H. – December 19, 2017 – Snowfall on a major summit in North America’s highest mountain range has more than doubled since the beginning of the Industrial Age, according to a study from Dartmouth College, the University of Maine, and the University of New Hampshire.
The research not only finds a dramatic increase in snowfall, it further explains connections in the global climate system by attributing the record accumulation to warmer waters thousands of miles away in the tropical Pacific and Indian Oceans.
The research demonstrates that modern snowfall in the iconic Alaska Range is unprecedented for at least the past 1200 years and far exceeds normal variability.
“We were shocked when we first saw how much snowfall has increased,” said Erich Osterberg, an assistant professor of earth sciences at Dartmouth College and principal investigator for the research. “We had to check and double-check our results to make sure of the findings. Dramatic increases in temperature and air pollution in modern times have been well established in science, but now we’re also seeing dramatic increases in regional precipitation with climate change.”
According to the research, wintertime snowfall has increased 117 percent since the mid-19th century in southcentral Alaska in the United States. Summer snows also showed a significant increase of 49 percent in the short period ranging less than two hundred years.
The research, appearing in Scientific Reports, is based on analysis of two ice cores collected at 13,000 feet from Mount Hunter in Denali National Park. According to the authors, accumulation records in the separate samples taken from just below the summit of the mountain known as “Denali’s Child” are in nearly complete agreement.
“It is now glaringly clear from our ice core record that modern snowfall rates in Alaska are much higher than natural rates before the Industrial Revolution,” said Dominic Winski, a research assistant at Dartmouth and the lead author of the report. “This increase in precipitation is also apparent in weather station data from the past 50 years, but ice cores show the scale of the change well above natural conditions.”
Once the researchers established snowfall rates, they set out to identify why precipitation has increased so rapidly in such a short amount of time. Scientific models predict as much as a 2 percent increase in global precipitation per degree of warming because warmer air holds more moisture, but this could not account for most of the dramatic increases in Denali snowfall over the studied period.
The research suggests that warming tropical oceans have caused a strengthening of the Aleutian Low pressure system with its northward flow of warm, moist air, driving most of the snowfall increases. Previous research has linked the warming tropical ocean temperatures to higher greenhouse gas concentrations.
The analysis includes a series of dramatic graphs that demonstrate extreme shifts in precipitation and reinforce the global climate connections that link snowfall in the high reaches of the North American continent with warm tropical waters. As noted in the paper, this same atmospheric connection accounts for a decrease in Hawaiian precipitation.
“Everywhere we look in the North Pacific, we’re seeing this same fingerprint from warming tropical oceans. One result is that wintertime climate in the North Pacific is very different than it was 200 years ago. This doesn’t just affect Alaska, but Hawaii and the entire Pacific Northwest are impacted as well,” said Winski.
The research builds on a recent study using the same ice cores that showed that an intensification of winter storm activity in Alaska and Northwestern Canada, driven by the strengthening Aleutian Low, started in 1740 and is unprecedented in magnitude and duration over the past millennium. The new record shows the result of that increase in Aleutian Low storm activity on snow accumulation.
For this analysis, researchers were able to segment the ice core records by seasons and years using markers like magnesium from spring dust to separate winter snow from summer snow. To account for snow layers getting squeezed and thinned under their own weight, the researchers applied four separate equations used in other studies, and in all cases the corrected record shows at least a doubling of snowfall.
According to the paper, while numerous snow accumulation records exist, “to our knowledge, no other alpine ice core accumulation record has been developed with such a thorough characterization of the thinning regime or uncertainties; all of the thinning models produce a robust increase in accumulation since the mid-19th century above late-Holocene background values.”
The researchers note that the findings imply that regions that are sensitive to warming tropical ocean waters may continue to experience rain and snowfall variability well outside the natural range of the past millennium.
“Climate change can impact specific regions in much more extreme ways than global averages indicate because of unexpected responses from features like the Aleutian Low,” said Osterberg. “The Mount Hunter record captures the dramatic changes that can occur when you get a double whammy from climate change – warming air combined with more storms from warming ocean temperatures.”
However, the researchers also note that the regional findings do not necessarily mean that the same level of snowfall increases will occur elsewhere throughout the mid- and high latitudes.
“Scientists keep discovering that on a regional basis, climate change is full of surprises. We need to understand these changes better to help communities prepare for what will come with even more carbon dioxide pollution in the air,” said Osterberg.
As part of the analysis, the authors suggest that current climate models underestimate the sensitivity of North Pacific atmospheric connections to warming tropical ocean temperatures. They argue that refining the way the modeled atmosphere responds to tropical ocean temperatures may improve rain and snowfall predictions in a warming world.
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Ho, hum.
From my viewpoint, in their rush to blame “climate change” they missed the biggest factor of all: increased pollution leads to increased cloud condensation nucleii. For example, watch aerosol loads from the pacific hit the southern Alaska mountain ranges:
Oh look, a hockey stick graph. That means it must be gullible warming.
If the temperature at the peak of a mountain was on average -20 c, and the climate warmed resulting in a temperature of – 15c, it would still snow. However, the warmer atmosphere would hold more moisture, resulting in more snow. So, paradoxically, a warmer atmosphere in some situations results in more snow. The thing to look at would be how low an altitude does the snow line stretch, is that snow line moving up? The glaciers may increase in volume, but where is their terminus?
I smell a hockeystick
They point to the warming pacific and implicitly label that as unnatural. On that assumption the increased snowfall is more than the ‘natural’ rate. But if the warmer ocean is just due to natural cycles, then the increased snow is the natural situation as well.
Jet stream pulls clouds over the Alaska.
http://pics.tinypic.pl/i/00952/6j0hzbtlv8qb.png
http://pics.tinypic.pl/i/00952/f82c84hxaljb.png
Is it me, or does this look a slightly less abrupt hockey stick graph? So supposedly warmer now causes more snow, but it didn’t have the same pronounced effect during the MWP and no corresponding substantial drop during the LIA? I know, they like to deny those existed despite the overwhelming evidence of both, but this leads me to believe their four equations just smoothed out the past while retaining the present and, voila, hock-stick! Only in this case instead of splicing data they could just use equations to have the same effect.
I know it’s confusing, Ed Hinton, but when you’re mired in a pseudo-religious thought process, you have to change the real stuff to suit your narrative. They keep contradicting themselves. You could make up a chart to make it easier for the rest of us to follow their regression. (Regression, because it isn’t progress.)
More snow means less sea level rise? How about that?
I doubt the whole garbage.
A couple of winters ago we had the “Rediculously Resilient Ridge” in the Pacific Ocean instead of a strong Aleutian Low. I believe that led to people freaking out about the “Polar Vortex” and a very cold winter here in the northeastern US. But maybe I’m wrong. At any rate, so-called teleconnections between, say, the Pacific ocean and the weather and climate someplace else are good to understand better.
The Iditarod and Iron Dog may have a good trail this year.
And, by extension, the glaciations are caused by global warming.
Love science.
Okay. I have read and reviewed all the arguments and stuff, looked at the charts and the pictures, and — well, in my speculative fiction about the Earth 350 years from now, I’m including a glacial maximum that starts some time in the mid-21st century and sends people off Earth looking for warmer planets. Pioneers, you know, kind of like the people who bought Conestoga wagons in the 19th century and moved westward. I’m calling them Conies.
My concern is that they’ll just go trash another planet, just like they’re trashing this one. But it’s speculative fiction, so the Sphenodonts might find them tasty.
Reduced snow cover = ‘climate change’.
Increased snow cover = ‘climate change’.
This ‘research’ and it’s stated conclusions are definitive proof that ‘climate change’ an unfalsifiable article-of-faith religion rather than objective, evidence-based science. Once and for all it should be filed under fake news.
Bezymianny eruption 2017-12-20 03:55 UTC (local time December 20 15:55). Height of ash plume ~ 15 km ASL extending to the N-E. The webcam is located in seismic station, approximately 7 km (4.3 mi) East of Bezymianny volcano.
https://youtu.be/xv041QDIOuk
Think what the explanation would have been if had snowed less?
Be careful. California may come after the water rights and lock it up for themselves.
A careful look at the graph shows most of the increase occurred before 1950. The increase slowed with rising CO2. This sort of rebuts the researchers’ conclusions.
Yes, God specifically designed the planet to make use of climate change by exporting warm pacific and CO2 to the North where nobody lives. Scientist continue to pay homage to him.
Plans to reintroduce Wolves to portions of the Continental Suburban U.S. must be underway by those same scientists.
I suggest Central Park in New York, and Twin peaks area of Frisco, as test ground
Once Osterberg used the term “carbon dioxide pollution”, what came immediately to my mind was an oft-used command by Col. Klink of Hogan’s Heroes….”Disssss-misssssed!!!”
I have in mind Brigadier General Jack D. Ripper, so concerned with our “precious bodily fluids” as greens are
Jet stream pulls the warm, moist air over to Alaska.
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Sorry.
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But CO2 molecules direct the Jet Stream, ren.
Absolute proof required for such a positive statement.
You obviously don’t realise just how knowledgable Ren is.
so.
They found a uni-corned goat (a mountain with doubling snow fall) , and it drinks water (climate change happens). This is proof that water (climate change) cause merging of goats’ corns (doubling snowfall). Isn’t it?
Yet another instance of p-hacking : search a high enough number of place in the world, and you are bound draw some “significant” result out of the statistical noise.
If some real link existed between “winter storms and tropical waters”, it would be true not just ” on a major summit in North America’s highest mountain range”, but on the world world, or at least all world’s highest mountain range.
From scanning the paper, I did not notice any link to the actual field data so that independent researchers could replicate the findings. I also did not see anything that would lead me to believe that the statistical methods and assumptions were evaluated by professional statisticians. We know from the Michael Mann “hockeystick” that climate scientists are notoriously prone to using bad assumptions and incorrect statistical methods. I would take this study with a grain of salt until further studies corroborate these conclusions.
Canada city