While there’s always lots of worry in California and Nevada over water supplies driven by the Sierra snowpack, and wailing in the MSM over what global warming will do to the snowpack, there doesn’t seem to be any trend, up or down.
John Christy has provided me with his latest paper, just published in E&E. I’m been authorized by him to present it here. In this case, no news is good news.
CHANGES IN SNOWFALL IN THE SOUTHERN SIERRA
NEVADA OF CALIFORNIA SINCE 1916
John R. Christy
Justin J. Hnilo
Earth System Science Center
University of Alabama in Huntsville
ABSTRACT
A time series (1916–2009) of annual snowfall totals for Huntington Lake (HL, elev.
2141 m) in the southern Sierra Nevada of California is reconstructed. A
reconstruction is (a) necessary because HL data after 1972 are mostly missing and
(b) possible because nearby stations reveal high correlations with HL, two above
0.90. The results show mean annual snowfall in HL is 624 cm with an insignificant
trend of +0.5 cm (+0.08%) ±13.1 cm decade−1. Similar positive but insignificant
trends for spring snowfall were also calculated. Annual stream flow and
precipitation trends for the region again were insignificantly positive for the same
period. Snow-water-equivalent comparisons, measured on 1 Apr since 1930 at
26 sites and since 1950 at 45, show similar small, mostly positive, and insignificant
trends. These results combined with published temperature time series, which also
reveal no significant trends, form a consistent picture of no remarkable long-term
changes in the snowfall of this area and elevation of the southern Sierra Nevada of
California since the early 20th century.
INTRODUCTION
Paleo-reconstructions of western U.S. precipitation indicate significant periods of
drought and surplus with relatively high multi-decadal variability (e.g. Meko et al.
2007). Could the region be entering a period of reduced precipitation, with a reduction
in snowfall in the mountains, perhaps as dry as that estimated from 12th century treerings (Meko et al 2007)? In terms of recent trends, Mote et al. 2005 found mostly
upward trends in snow water equivalent in the southern Sierra for the period limited to
1950–1997 (48 years, or about half of the current study). They found positive trends as
well in the southern Rocky Mountain region, while poleward of approximately 38°N
there were widespread declines.
Barnett et al. 2008 indicate that for 1950–1999 most of the Western U.S. snowyregions show warming temperatures and earlier peak runoff, suggesting a trend towardless snow and more rain. This could be an ominous development for water resourceplanners as the mountain snowmelt, both its quantity and timing, provides a majorresource on which municipal, industrial and agricultural systems rely.
We shall examine snowfall itself because it is a vital metric to understand since it is critical for businesses and operations related to snow (winter sports, road clearing, etc.) as well as
snow-dependent ecological systems.
The question we will examine is whether a tendency in snowfall in the Southern
Sierra Nevada (So. Sierra) is detectable. The So. Sierra are important for many
reasons including their location as one of the most southern mountain ranges in the
U.S. with significant water resource impacts and thus potentially an early indicator of
climate change since modeled changes show significant warming here due to
enhanced greenhouse gas concentrations (e.g. Snyder et al. 2002). Mote et al. 2005
examined only 48 years of data and Barnett et al. 2008 only 50 years, but both found
a slight upward trend in water-resource availability in the So. Sierra. In an earlier
study of snow water equivalent (SWE) measured on 1 Apr of each year, Howat and
Tulaczyk 2005 found no trend in SWE for 177 snow courses.
However, by subtracting 1 Apr from 1 Mar SWE there appeared to be a small gain (loss) in Δ SWE for 1950–2002 at the higher (lower) elevations along with insignificant increases in water volume for Nov–Mar. The implication here is that over a shorter period of time,
the SWE contours on 1 Apr have risen in elevation. However, while extremely
valuable as a water resource index for late-spring and summer runoff, SWE on 1 Apr
often misrepresents the actual total snowfall during the cold season as early snows
may have melted by this time and later snows are not included (see examples later).
We shall look at annual snowfall as a different, though obviously related, climate
metric relative to SWE.
Has snowfall changed over a longer period in the mid-elevation (∼2000 m) of the
So. Sierra? This question has links to our previous study of the So. Sierra in which
seasonal maximum (TMax) and minimum (TMin) temperatures were produced
(Christy et al. 2006). The wet-season (Dec-May) temperature trends for 1910–2003
were not significantly different from zero (TMax +0.08, TMin −0.01 °C decade−1),
suggesting that if precipitation trends were near zero, then snowfall might also show
little change. Indeed, an examination of annual “water year” (Jul – Jun) precipitation
totals for this region’s climate division indicates a trend of +0.2% decade−1 (1916–2009)
while that of the nearest long term station (Fresno) shows +2.7% decade−1. Thus a
look at a longer snowfall record, and attendant variables such as runoff, is one way to
examine consistency, at least obliquely, to the temperature record.
CONCLUSION
With the available data from six mid-elevation stations in the Southern Sierra region of
California we reconstructed annual snowfall totals for 36 missing years of the
Huntington Lake record to complete the time series (1916–2009). The standard error
of the missing years is calculated to be ±36 cm, or 6% of the 94-year annual mean of
624 cm in the most robust estimation method (though we utilized the average of six
methods which reduces the standard error further.)
The results of both the annual and spring snowfall time series indicate no
remarkable changes for the 1916–2009 period in the basins drained by the Merced, San
Joaquin, Kings and Kaweah Rivers. In the six reconstructions the range of trend results
varied only slightly from −0.3% to +0.6 % decade−1. With a consensus trend of only
+0.5 cm (+0.08%) decade−1 ±13.1 cm decade−1 there is high confidence in the
“no-significant-trend” result. The corroborating information on temperature trends
(Christy et al. 2006), stream flow, precipitation and shorter period snow water
equivalent trends presented here are consistent with “no-significant-trend” in So. Sierra
snowfall near 2000m elevation since 1916.
==================================
Paper (PDF) is here:
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
MikeA says:
July 25, 2010 at 1:22 am
Seems to sort of confirm what James Overland was saying recently http://www.sciencedaily.com/releases/2010/06/100611093710.htm . I always think that if almost everyone criticises an new idea it may have merit.
______________________
Criticized for saying ”
“Irreversible change
The Arctic is warming more than twice as fast as the rest of the planet. This is known as Arctic amplification — a much debated phenomenon at the IPY-OSC, where 2400 polar scientists have gathered to discuss the huge amount of research and new findings which are the direct result of the International Polar Year.
The changes are happening a great deal faster than the scientific community expected. Given the recent reduction of the area of multi-year sea ice and reduced ice thickness, it is unlikely that the Arctic can return to its previous condition.
“The changes are irreversible,” says Dr Overland.”
Where have we heard this before? Normal is not irreversible.
I love how Dr. Christy uses both “Robust” and “Consensus” in this nature-as-usual, anti-alarmist paper.
Here’s a link to the NPR story: http://www.npr.org/templates/story/story.php?storyId=120846593 for those who don’t believe me.
MikeA says:
July 25, 2010 at 1:22 am
Seems to sort of confirm what James Overland was saying recently http://www.sciencedaily.com/releases/2010/06/100611093710.htm . I always think that if almost everyone criticises an new idea it may have merit.
________________________________________________________
Actually studies were done and papers were written on that topic by J. Scott Armstrong
Plain Prose: It’s Seldom Seen in Journals: Written by Dick Pothier: From the Philadelphia Inquirer, March 23, 1982.
“If you want to publish an article in some scientific or medical journal, here is some unusual advice from Scott Armstrong, a professor of marketing at the University of Pennsylvania’s Wharton School: Choose an unimportant topic. Agree with existing beliefs. Use convoluted methods. Withhold some of your data. And write the whole thing in stilted, obtuse prose….
…obscure writing helps those who have little to say. And having little to say may also be an advantage, especially if the author withholds some significant data. “This will allow the researcher to continue publishing slightly different versions of the same research,” which Armstrong says is a common practice…”
A list of Armstrong’s papers is here The papers of interest are the earlier papers and start at about 150 such as :
This paper, a real laugh:
171. J. Scott Armstrong (1980), Bafflegab Pays
, Psychology Today, 12
““If you can’t convince them, confuse them.” Simply put, this is the advice that J. Scott Armstrong, a marketing professor at the Wharton School, coolly gives his fellow academics these days. It is based on his studies confirming what he calls the Dr. Fox hypothesis: “An unintelligible communication from a legitimate source in the recipient’s area of expertise will increase the recipient’s rating of the author’s competence.”
Eight years ago, Dr. Myron L. Fox gave a celebrated one-hour talk, followed by a half- hour discussion period, on “Mathematical Game Theory as Applied to Physician Education.” His audiences were professional groups, including psychologists, psychiatrists, social workers, and educators; afterward, on anonymous questionnaires, they said they found the lecture clear and stimulating.
Fox, in short, was a smashing success. He was also a complete phony—a professional actor whom three researchers had told to make up a lecture of double-talk, patching raw material from a Scientific American article into nonsequiturs and contradictory statements interspersed with jokes and meaningless references to unrelated topics…..
Or this paper on the theory: There are no SEERS there are only SUCKERS.
174. J. Scott Armstrong (1980), The Seer-Sucker Theory: The Value of Experts in Forecasting, Technology Review, June/July, 16-24
“Assume for a moment that the seer-sucker theory is true – that expertise is useless in forecasting change. Is there any rational explanation for why clients continue to purchase worthless information?
One explanation is that the client is not interested in accuracy, but only in avoiding responsibility. A client who calls in the best wizard available avoids blame if the forecasts are inaccurate….
… Another possibility is that researchers find it easier to publish evidence refuting than confirming the common notion that expertise is useful. However, in light of a 1977 study by Michael Mahoney, this possibility seems remote. Mahoney asked 75 re viewers to referee a paper. Two versions of the paper were presented to randomly selected subsamples of reviewers. The papers differed only in the results: one version had results favoring the common wis dom of the day and the other refuted it. A strong bias was found toward accepting the study that agreed with a commonly held hypothesis and rejecting the one that contradicted this hypothesis.”
Dr Armstrong’s papers are a gold mine when it comes to refuting the “peer-reviewed” superiority complex seen in AGW circles today.
Rattus Norvegicus says:
July 25, 2010 at 8:07 am
Here’s a link to the NPR story: http://www.npr.org/templates/story/story.php?storyId=120846593 for those who don’t believe me.
\
It is not about whether I believe you, a self described rodent, it is about whether NPR should be considered a fair and reliable source of information on any topic that involves politics.
NPR generally tries to put a fair face on their reporting, but it is quite difficult for NPR to portray non-leftist information when its listeners write such nasty responses to any story where they exercise balance. Singing to the choir is just so much easier.
This same problem exists for most media, including right leaning FOX. The difference is that FOX is pretty much alone, with other outlets quite solidly on the left and preaching to their choir.
I realise that I failed to point out that James Overland has raised the possibility of snowier winters for the northern hemisphere. I forgot that the normal stuff about the ice melting might be controversial. He is predicting a snowier east coast USA and I was guessing the many places would remain in balance, such s S.Sierra.
I always cringe, when I hear the term “prove” or “proof” associated with anything of a scientific nature. There is no such thing in science. The terms “prove” and “proof” should only be referred to in matters of mathematics or logic.
I phrased that last improperly. Perhaps old age is creeping up on me. I should have said, “matters of logic, [b]such as[/b] mathematics”.
Wouldn’t the first “trends” show up in areas currently occupied by jet streams or where jet streams have historically been?
Snowpack and water supply are outstanding this year.