Snowpack declines in Rockies unusual compared to past

Jun 09, 2011
Annual tree rings record a detailed history of drought (narrow rings) and wetness (wide rings). This sample from a dead Douglas fir tree in the Santa Catalina Mountains near Tucson, Ariz., has nearly 400 rings and dates back to the year 1600. Stress cracks, visible in the foreground of the image, occur as the dead wood dries and contracts. (Photo credit: Copyright Daniel Griffin)

(PhysOrg.com) -- The researchers evaluated the recent declines using snowpack reconstructions from 66 tree-ring chronologies, looking back 500 to more than 1,000 years.

The reduction in snowpack in the over the last 30 years is unusual compared to the past few centuries, according to a new study that includes University of Arizona researchers.

Previous studies attribute the decline to unusual springtime warming, more precipitation falling now as rather than snow and earlier snowmelt.

The warming and snowpack decline are projected to worsen through the 21st century, foreshadowing a strain on water supplies. from winter snowpack – layers of snow that accumulate at high altitude – accounts for 60 to 80 percent of the annual water supply for more than 70 million people living in the western U.S. 

U.S. Geological Survey scientists, with partners at the UA, University of Washington, University of Wyoming and University of Western Ontario, led the study.

"We were interested in seeing how snowpack varied in three watersheds," said co-author Connie A. Woodhouse, UA associate professor of geography and regional development. "One in the northern Rockies that is the headwaters of the Columbia, one in Yellowstone that is the headwaters of the Missouri and one for Colorado that includes the headwaters of the Colorado." 

Secretary of the Interior Ken Salazar said, "This scientific work is critical to understanding how climate change is affecting western . It helps land managers adapt to changing conditions on the ground, assists water managers with planning for the future, and gives all of us a better understanding of the real impacts that carbon pollution is having on our resources and our way of life."

Snowpack declines in Rockies unusual compared to past
Connie Woodhouse and Mark Losleben of the UA examine a tree-ring core from a drought-stressed Douglas fir tree in the Santa Rita Mountains south of Tucson, Ariz. (Photo credit: Copyright 2009 Daniel Griffin)

The researchers evaluated the recent declines using snowpack reconstructions from 66 tree-ring chronologies, looking back 500 to more than 1,000 years. The network of sites was chosen strategically to characterize the range of natural snowpack variability over the long term, and from north to south in the Rocky Mountains.

With a few exceptions (the mid-14th and early 15th centuries), the snowpack reconstructions show that the northern Rocky Mountains experience large snowpacks when the southern Rockies experience meager ones, and vice versa. Since the 1980s, however, there were simultaneous declines along the entire length of the Rocky Mountains, and unusually severe declines in the north.

"Over most of the 20th century, and especially since the 1980s, the northern Rockies have borne the brunt of the snowpack losses," said USGS scientist Gregory Pederson, the lead author of the study.

"Most of the land and snow in the northern Rockies sits at lower and warmer elevations than the southern Rockies, making the snowpack more sensitive to seemingly small increases in temperature. Also, winter storm tracks were displaced to the south in the early 20th century and post-1980s. Forest fires were larger, more frequent and harder to fight, while Glacier National Park lost 125 of its 150 glaciers."

Pederson conducted part of the research at the UA's Laboratory for Tree-Ring Research. He earned his doctorate from the UA's School of Natural Resources and the Environment in 2010.

USGS scientist and co-author Julio Betancourt said, "The difference in snowpack along the north and south changed in the 1980s, as the unprecedented warming in the springtime began to overwhelm the precipitation effect, causing snowpack to decline simultaneously in the north and south. Throughout the West, springtime tends to be warmer during El Niño than La Niña years, but the warming prior to the 1980s was usually not enough to offset the strong influence of precipitation on snowpack." 

The La Niña episode this year is an example with lots of snow in the north while severe drought afflicts the south. But, in the north, this year's gains are only a small blip on a century-long snowpack decline.

In the West, the average position of the winter storm tracks tend to fluctuate north and south around a latitudinal line connecting Denver, Salt Lake City and Sacramento. In El Niño years, winter storms track south of that line, while in La Niña years, they track to the north.

This study supports research by others estimating that between 30-60 percent of the declines in the late 20th century are likely due to greenhouse gas emissions. The remaining part of the trend can be attributed to natural decadal variability in the ocean and atmosphere, which is making temperatures that much warmer.

Pederson said, "What we have seen in the last few decades may signal a fundamental shift from precipitation to temperature as the dominant influence on western snowpack."

The study, "The unusual nature of recent snowpack declines in the North American Cordillera," is available from Science magazine online.

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Vendicar_Decarian
3.5 / 5 (14) Jun 09, 2011
Where are the Kook Tards claiming that the reduction in the snow pack is all a result of the chaotic magnetic output from the mostly iron neutron star that is hiding inside the sun?

I have a roll of tinfoil here, and thought they could use some.
ubavontuba
2 / 5 (10) Jun 09, 2011
Who writes these lies? The Rockies are BURIED in snow!

"Wyomings Climate: May 2011

Mountain snowpack continued to be the major story in Wyoming this month. By the end of May, statewide snow water equivalent (SWE) topped an astounding 327% of historical average (compared to 1971-2000)."

327% of normal! OMG! The snow is disappearing! Run, Chicken Little, and tell the fox!

http://www.wrds.u...1May.pdf

More:

http://denver.cbs...untains/

http://www.nytime...now.html

http://etfdailyne...ags-unl/

http://www.nwd-mr...snow.pdf
Skeptic_Heretic
5 / 5 (5) Jun 09, 2011
Long term vs short term.

40 years is the short term comparison, 1000 years is the long term comparison.
ubavontuba
1.9 / 5 (9) Jun 09, 2011
40 years is the short term comparison, 1000 years is the long term comparison.
Fine. What was it like then, just a mere 50 of your long term time units back? Shall we use that as the "normal" baseline?

Skeptic_Heretic
4.2 / 5 (5) Jun 09, 2011
40 years is the short term comparison, 1000 years is the long term comparison.
Fine. What was it like then, just a mere 50 of your long term time units back? Shall we use that as the "normal" baseline?
I'm just telling you where the difference in statistics is comming from. I haven't read the paper yet so I can't really comment on it.
Decimatus
3.6 / 5 (12) Jun 10, 2011
Who writes these lies? The Rockies are BURIED in snow!

"Wyomings Climate: May 2011

Mountain snowpack continued to be the major story in Wyoming this month. By the end of May, statewide snow water equivalent (SWE) topped an astounding 327% of historical average (compared to 1971-2000)."

327% of normal! OMG! The snow is disappearing! Run, Chicken Little, and tell the fox!


Funny, snow levels drop for 30 years and when you have 1 winter(in a single state mind you) of "normal" snowfall, it blows away the data of the timeframe in which the researches were talking about.

Long story short, your stupidity has only added further validity the above study.
Vendicar_Decarian
2.3 / 5 (9) Jun 10, 2011
UbavonTard.... I have a roll of tinfoil here.

You wanna make a hat with it don't you?

Fresh crinklie tinfoil.. Your favorite..... Come get some... Tard boy...
NotParker
2.2 / 5 (10) Jun 10, 2011
TWO YEARS of huge SNOWPACK

May 2011 SnowPack

"Thanks to a blizzard-filled winter and an unusually cold and wet spring, more than 90 measuring sites from Montana to New Mexico and California to Colorado have record snowpack totals on the ground for late May, according to a federal report released last week."

http://www.nytime...now.html

June 2010:

http://wattsupwit...ne-2010/
NotParker
1.8 / 5 (13) Jun 10, 2011
Tree ring chronologies????????

Not actual data?

Ha ha ha ha ha ha ha ha

January Through April North American Snow Cover Has Increased 4% Over The Last Twenty Years

http://stevengodd...y-years/
NotParker
2.2 / 5 (10) Jun 10, 2011
"In spite of the rapid global warming, this period saw a 19% increase in snowpack in the Cascades, although this trend does not exceed the statistical uncertainty"
dutchman
3.2 / 5 (9) Jun 10, 2011
So what is new? This thing has been happening for the last few years, all over the world: The Alps, Mt Kilimanjaro (soon to be without a snowcap at all,) even the Himalayas.

Oh, and one or even two seasons of WEATHER DOES NOT CONSTITUTE CLIMATE.
ubavontuba
2.1 / 5 (11) Jun 10, 2011
Funny, snow levels drop for 30 years and when you have 1 winter(in a single state mind you) of "normal" snowfall, it blows away the data of the timeframe in which the researches were talking about.
Excessive amounts of snow have actually fallen for several seasons now. The Arctic ice has substantially increased since 2007.

Long story short, your stupidity has only added further validity the above study.
Naw, that would be morons like you who believe what you're told to believe, without critically examining the data for yourself.

Try doing a little research. You'll strangely find that most of the data used in GW papers cuts off at 2008. Why? Becasuse since then, the data has sharply skewed away from their expectations!

ubavontuba
2.8 / 5 (9) Jun 10, 2011
So what is new? This thing has been happening for the last few years, all over the world: The Alps, Mt Kilimanjaro (soon to be without a snowcap at all,) even the Himalayas.

Oh, and one or even two seasons of WEATHER DOES NOT CONSTITUTE CLIMATE.
Bad examples. Even the climate scientists who first sounded these alarms have backed down from this stance.

http://appliedcli...ictions/

Try doing a little research before you spout off next time, okay?

Skeptic_Heretic
4.2 / 5 (6) Jun 10, 2011
Uba, can you cite your source for the claim of increasing artic multiyear ice? Everything I've read claims the exact opposite of your claim.
NotParker
1.9 / 5 (9) Jun 10, 2011

Multi-Year Ice Has Grown More Than 30% In The Last Three Years

http://stevengodd...e-years/

Antarctic Sea Ice is fine

http://arctic.atm...ctic.png
ubavontuba
2.3 / 5 (9) Jun 10, 2011
@Venditard_Detardian:

I have a roll of tinfoil here.

You wanna make a hat with it don't you?

Fresh crinklie tinfoil.. Your favorite..... Come get some...
And I have a nice bucket of fresh beach sand here for you to bury your head in, to help you continue to ignore the facts.

Come and get it tard of tards ...nice and fresh, not more than one or two stinging jellyfish ...I promise.
ubavontuba
1.6 / 5 (7) Jun 11, 2011
Uba, can you cite your source for the claim of increasing artic multiyear ice? Everything I've read claims the exact opposite of your claim.
We've been over this before. Have you forgotten already?

Anyway, NotParker provided a couple of decent references. Check them out.
Skeptic_Heretic
4.6 / 5 (5) Jun 11, 2011

Multi-Year Ice Has Grown More Than 30% In The Last Three Years

http://stevengodd...e-years/

When you say, "greatly increased" you do realize that article is telling you one thing, and you're viewing graphs telling you something entirely different.

The increase of multiyear ice is still well below the running average. The graphs attached ot that article show a marked drop in multiyear ice, most likely due to the rapid loss of several ice shelves all at once in 07 and 08, and a small but non-zero recovery not exceeding 5% of running average in total.

To use the numbers on the graph, lets say you have 40,000. You lose 10,000 over a few months, then you lose 20,000 all at once in the next month.

Would making 4,000 of it back the following month mean you're doing well? I wouldn't say so. I think the timescales you're looking at are too short to come up with any form of certainty on ice status.
NotParker
1.9 / 5 (9) Jun 11, 2011
Try and remember that GLOBAL Sea Ice anomaly is just slightly below normal (during the satellite era). And also try and remember the satellite era exactly matches up with the warm PDO cycle that recently ended. I think warmists are in for a surprise when the cold PDO has been around for a while.

Even so, GLOBAL sea ice anomaly is HIGHER than it was in:

1980,1984,1985,1986,1990,1995,1996,1997,2001,2002 etc etc etc

http://arctic.atm...rend.jpg

And Southern Sea Ice anomaly is definitely still about normal and was well above normal in 2007/2008 and 2010.

http://arctic.atm...ctic.png

As for snow ... there is a real danger that way less than usual will melt in western north america this year leading to albedo changes.
NotParker
1.9 / 5 (9) Jun 11, 2011
Willis Eschenbach at WUWT was kind enough to graph the data in the paper we are discussing.

I think the data tells a better story. There was less snowpack in 1942 in the Northern Cordillera and less snowpack in the Southern Cordillera in 1977.

There seems to be nothing unusual in the last 30 years.

http://wattsupwit...re-41450

Wait until the cold PDO has been around for 30 years!
Skeptic_Heretic
3.8 / 5 (6) Jun 11, 2011
Try and remember that GLOBAL Sea Ice anomaly is just slightly below normal (during the satellite era).
Unfortunately, that isn't what we're talking about. We're specifically talking about multiyear ice status.
Even so, GLOBAL sea ice anomaly is HIGHER than it was in
Well yes, calving of land ice does indeed increase sea ice extent, but again, we're talking multiyear ice, not ice extent.

Your Watts reference, unfortunately is only sampling a component of the total. One would arguably state that your articles are selective cherry picking of stats favorable to your position.
NotParker
2 / 5 (8) Jun 11, 2011
Multi year ice is up. Already shown.

In the Antarctic, there is about 15 million sq km of sea ice.
In the Arctic, there is about 14 million sq km of sea ice.

Warmists only discuss the arctic because extent is lower than it was in 1979/1980 (the beginning of the satellite era)

The do not discuss the Antarctic because it is higher than it was in 1979/1980.

Thw WUWT is discussing all the data given by the papers authors. If there is more data, they did not release it.

Remember, it is now cold PDO. Warm PDO coincided with satellite era.

Vendicar_Decarian
2.9 / 5 (7) Jun 11, 2011
"In the Arctic, there is about 14 million sq km of sea ice." - NoParker

Which of course is a lie.

That is roughly the historical peak value.

This winter the peak was 1 million km**2 lower. - tied with the lowest ice extent ever recorded in human history.

Ice extent continues to be 1 million km**2 lower than the average for this time of year.

Due to the warming arctic, minimum ice extents are now averaging between 1.25 km**2 and 2 km**2 lower than historical averages.

Poor, lying ParkerTard.

NotParker
2 / 5 (8) Jun 11, 2011
About 6% lower than 1996.

By "historical averages" you mean since 1979 right?

And the late 1970s were the coldest period in the last 80 years. It was so cold the ice age scare was making the cover of news magazines.

The arctic was also warm in the 1920s/30s/40s. Its a cycle.

If Global Warming was actually "global", why no change in Antarctic Sea Ice -- which covers a similar area?
NotParker
2.3 / 5 (9) Jun 11, 2011
"Writing as background for their study, authors Wood and Overland (2010) note that "the recent widespread warming of the earth's climate is the second of two marked climatic fluctuations to attract the attention of scientists and the public since the turn of the 20th century," and they say that the first of these -- "the major early 20th century climatic fluctuation (~1920-1940)" -- has been "the subject of scientific enquiry from the time it was detected in the 1920s." Furthermore, they write that "the early climatic fluctuation is particularly intriguing now because it shares some of the features of the present warming that has been felt so strongly in the Arctic."

http://www.nipccr...0a2.html
ubavontuba
2.1 / 5 (7) Jun 11, 2011
As for snow ... there is a real danger that way less than usual will melt in western north america this year leading to albedo changes.
You got that right. There's unprecedented levels of snow on the ground.

I mean just look at this map:

http://www.wcc.nr...1105.gif

All the different shades of blue represent levels greater than 110% of normal (the darker the blue, the more snow there is), the purple is anything greater than 180%. That's virtually all there is on the map! Purple and blue!

NotParker
2.1 / 5 (7) Jun 11, 2011
"The snowpack we have right now is 525 percent of normal"

"Bob Bonar, the general manager at Snowbird, said the mountain received more than 775 inches of snow this season, well above its average of 500.

We even got 20 inches of powder over Memorial Day weekend, and our current average base is more than 15 feet,

http://www.nytime...ows.html
ubavontuba
1.8 / 5 (5) Jun 12, 2011
This winter the peak was 1 million km**2 lower. - tied with the lowest ice extent ever recorded in human history.
Actually, this year the sea ice density was a little higher, and the snow cap was much more extensive:

http://igloo.atmo...;sy=2011

Ice extent continues to be 1 million km**2 lower than the average for this time of year.
This time of year in 2007, versus this time of year in 2011:

http://igloo.atmo...;sy=2011
chromal
4 / 5 (4) Jun 12, 2011
Who writes these lies? The Rockies are BURIED in snow!

I guess that if you had read the article a little more closely, you'd've seen that it describes the historical difference between northern and southern rocky mountain snowpacks. "Lies!" is more than a little sensational, though perhaps if you could be more specific in your accusations, if you had a point other than that you don't like science, it would be more clear?

A couple of things to keep in mind: snowpack is generally described in terms of 'average' which is generally taken from observations over the past 30-40 years. Given this study is about the decline during that same period, you won't see a decline expressed loudly in terms of those averages.

Parts of the southern rocky mountains, particularly in southern Colorado and northern new mexico are way below this average, for what that's worth.

Anyway, this seems like a very dry (no pun intended) statistical study, not remarkable and certainly not controversial.
NotParker
2.1 / 5 (7) Jun 12, 2011
chromal, what decline?

It seems to me that picking 30 years seems strange since that is when the last warm PDO started.

Going back 60 years might be more scientific since PDO's tend to last 20-30 years.

It would be like someone claiming there was less snow in the 6 month period April-Sept compared to Oct-Mar (although maybe not this year considering how much snow there is!)

http://wattsupwit...re-41450
ubavontuba
2 / 5 (4) Jun 13, 2011
I guess that if you had read the article a little more closely, you'd've seen that it describes the historical difference between northern and southern rocky mountain snowpacks.
Maybe you should go back and read the first few paragraphs. They're predicting declining smowpacks, in spite of increasing snowpacks! They're talking about less snow overall. The north vesus south thing was just an explanation concerning variability.

if you had a point other than that you don't like science...
Maybe you're not scientist enough to notice my references? Or, is it that they're too "science-y" for you to understand?

snowpack is generally described in terms of 'average' which is generally taken from observations over the past 30-40 years.
Actually, the baseline period used is from 1971 t0 2000 (unusually snowy years!). All the snow we've had this year makes up for most (if not all) of the recent relatively "dry" years.

cont...
ubavontuba
2 / 5 (4) Jun 13, 2011
Parts of the southern rocky mountains, particularly in southern Colorado and northern new mexico are way below this average, for what that's worth.
Right. Didn't you see it on the snow map I provided? It's a relatively small area compared to that with excessive snow.

Anyway, this seems like a very dry (no pun intended) statistical study, not remarkable and certainly not controversial.
It is controversial. Sixty-six trees in hundreds of thousands of square miles, is hardly representative!

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