From Penn State , another Mann paper with proxy sets, and a divergence problem. At least they are talking about the MWP, or as they call it, the Medieval Climate Anomaly which had been erased in previous papers Mann had been involved with. The attempt to link paleo data to the PDO is interesting too. Mann was not lead author, and hopefully none of the flawed PCA math he’s used to mess up other papers made it into this one. I’m hopeful, as the SI contains some equations/code.
The gist of the paper is this: they wanted to determine patterns of drought in the Pacific Northwest, so the authors used proxy data obtained both from tree rings and from oxygen isotopes related to lake sediments.
According to lead author Byron Steinman.“The data matched up on a short-term, decadal scale, however, on a longer-term, century scale, the records diverged. The tree-ring data suggests dry conditions during the Medieval Climate Anomaly summers while the isotope data suggest wetter-than-expected winters.”
New methods help scientists shed light on ancient climates
Tree ring and oxygen isotope data from the U.S. Pacific Northwest do not provide the same information on past precipitation, but rather than causing a problem, the differing results are a good thing, according to a team of geologists.
The researchers are trying to understand the larger spatial patterns and timing of drought in the arid and semiarid areas of the American West.
“We generally understand that the Medieval Climate Anomaly, a warm period in much of the northern hemisphere that occurred about 950 to 1250 was a dry period in the American West,” said Byron A. Steinman, postdoctoral researcher in meteorology, Penn State. “But there is complexity to the patterns of drought and it may not have been dry in winter in the Pacific Northwest.”
East of the Cascade Mountains, the Pacific Northwest is dry and hot in the summer and wet in the winter now.
Estimates of past precipitation are made from proxies like tree rings, which can record amounts of precipitation and temperature. But tree rings are better at recording what happens during the spring and summer, when the tree is growing, than in the winter when the tree is not.
Steinman, who worked with Mark B. Abbott, professor of geology and planetary science, University of Pittsburgh, his Ph.D. advisor, looked at oxygen isotopes found in 1,500 years of sediment at the bottom of lakes. The isotopic composition of these sediments can reflect the amount of water that enters the lake, especially during the wet season.
The analyzed lake sediments contain calcium carbonate in the form of calcite. The oxygen isotope ratios in this mineral relate directly to the isotope ratio of water in the lake. The researchers looked at sediment from two small lakes in Washington state. Castor Lake is on a plateau and water inflow is only from precipitation and groundwater. This lake has no outflow, so most water loss is through evaporation. Lime Lake, on the other hand, loses the majority of water through a permanent outflow stream, although all water enters in the same manner as for Castor Lake. By comparing the two lakes, the researchers could determine the water balance between evaporation and precipitation.
The researchers looked at two stable isotopes of oxygen — oxygen 16 and oxygen 18 — in the sediments. Oxygen 16 is lighter than oxygen 18, so during evaporation and lake draw down, more oxygen 16 evaporates out and the calcite in the sediments contain more oxygen 18. If the lakes are full of water, then there will be more oxygen 16 in the calcite. The layers of sediment that are laid down each year can be dated either by using carbon 14 dating of organic material or by locating layers of tephra — volcanic ash, that signifies known — dated volcanic eruptions. In this way, the researchers could pinpoint when drought occurred.
“The tree ring data and isotope data match up on a short term, decadal scale,” said Steinman. “On a longer term, century scale, the records diverge.”
While the decadal ups and down remain the same for both proxies, when viewed on a 100-year or longer scale, the proxies show differences. The tree ring data suggest dry conditions during the Medieval Climate Anomaly summers, while the isotope data suggests wetter than expected winters.
Comparing the lake sediment records to existing records of the Pacific Decadal Oscillation, a warming or cooling of the coastal waters off the Pacific Northwest, the researchers report in the current online issue of the Proceedings of the National Academy of Sciences “a strong centennial timescale relationship over the past 1,500 years between winter precipitation amounts in eastern Washington and Pacific Decadal Oscillation temperature anomalies.”
The PDO is linked to the El Nino Southern Oscillation, a tropical phenomenon that influences global weather patterns. During and before the Medieval Climate Anomaly, the North Pacific Ocean was warmer and Washington had greater precipitation than during the Little Ice Age, which occurred from about 1450 to 1850, when there was less precipitation.
Steinman used a previously published and validated model based on established lake physics and modern recorded precipitation and temperature to determine the amounts of rainfall indicated by the isotopic record
“The best thing we could do now is to produce additional quantitative precipitation records, this time with different lake systems,” said Steinman.
Other researchers on this project were Michael E. Mann, professor of meteorology and geosciences and director of the Penn State Earth System Science Center; Nathan D. Stansell, former Ph.D. student at the University of Pittsburgh, now a research fellow, Byrd Polar Research Center, Ohio State University and Bruce Finney, professor of biological sciences, Idaho State University.
The National Science Foundation funded this research.
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Paper: 1500 year quantitative reconstruction of winter precipitation in the Pacific Northwest, by Byron A. Steinman, Mark B. Abbott, Michael E. Mann, Nathan D. Stansell, and Bruce P. Finney, PNAS, 2012.
Abstract
Multiple paleoclimate proxies are required for robust assessment of past hydroclimatic conditions. Currently, estimates of drought variability over the past several thousand years are based largely on tree-ring records. We produced a 1,500-y record of winter precipitation in the Pacific Northwest using a physical model-based analysis of lake sediment oxygen isotope data. Our results indicate that during the Medieval Climate Anomaly (MCA) (900–1300 AD) the Pacific Northwest experienced exceptional wetness in winter and that during the Little Ice Age (LIA) (1450–1850 AD) conditions were drier, contrasting with hydroclimatic anomalies in the desert Southwest and consistent with climate dynamics related to the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). These findings are somewhat discordant with drought records from tree rings, suggesting that differences in seasonal sensitivity between the two proxies allow a more compete understanding of the climate system and likely explain disparities in inferred climate trends over centennial timescales.
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Data deposition: Precipitation reconstruction data are available for download at the NCDC/NOAA Paleoclimate data archive website (www.ncdc.noaa.gov/paleo).
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This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1201083109/-/DCSupplemental.
I note that following my last post above, david brown got so flustered that he posted nine (9) consecutive replies.☺ Almost all of them contain brown’s usual misinformation.
And I note that brown cannot answer Bill Tuttle’s questions, instead referring to imaginary links.
The planet is still naturally emerging from the Little Ice Age, along the same long-term trend line. There is no acceleration where temperatures break out over their long term parameters, and despite the 40% rise in [harmless, beneficial] CO2, there is no measurable change in the trend:
click1
click2
click3
click4
click5
click6
click7
I have more such charts for Mr brown if he is interested, on many different time scales and from many different sources. The fact is that the large increase in CO2 has not affected the long term global warming trend since the LIA. The conclusion is inescapable: the effect of CO2 is much smaller than claimed. It is so small, in fact, that it is unmeasurable. It cannot be discerned in the natural warming trend. That debunks the “carbon” scare, no?
Yes. Yes it does.
david brown says:
July 8, 2012 at 12:23 pm
here is the murphy study bill. i am including sources to counter the accusation that i have nothing to back me up. you can see i have a lot to back me up. peer reviewed studies. and data from nasa. you seem to have nothing?
Congratulations — the idea of providing a source finally seems to have sunk in.
Your last sentence, however, tells me you either still haven’t read any of the links I provided or you have the attention span of a goldfish.
are they peer reviewed published sources smokey. your last source was from a timber company. hardly scientific.’ the conclusion is inescapable the effect of c02 is much smaller than claimed? ” according to every major science group on earth ,including nasa and the world met your conclusion is very escapable. ”it is so small it is immeasurable?” no smokey it is not immeasurable. as a matter of fact it is constantly being measured. i will give you the measurements if you like? my links are not imaginary. the tung/ camp study actually exists. as does the murphy study. i have actually cut and pasted the papers. you can go to the link quite easily . they are all on line. i suppose NASA is an imaginary link too? what caused the LIA to end? shall i tell you?. an increase in solar activity. it did not end by magic as you seem to think. that increase in solar activity is no longer relevant. the sun is in a minimum at present. i will check your links again out of politeness. but i sincerely hope the standard is higher than the cave paintings you posted last time?
”wood for trees” is not a scientific link smokey. and your graphs contains no information as to who is responsible for them. who is the research group who did the measurements and formulated the graphs? . are they independent studies or done by a recognised scientific org ?you could have drawn them up for all i know. name the sources on which the graphs are based. and then as all good science studies do, please explain the conclusions with some kind of commentary . you know study papers. names, dates, .the names of the science journals the graphs are originally published in etc. i cant believe you expect to be taken seriously with the chicken scratchings you have posted. far more confirmed details please.
you are wrong bill i browsed the links you posted. but if their conclusions are that the planet is not warming. or that aerosols do not cool climate. or that the sun is not decreasing in activity and is not a forcing agent . then they have little credibility.
”you have more such charts smokey?” heaven forbid. just go to the nasa website if you want good science. they include in depth analysis. what you offer is not even on a primary school level
smokey. first please explain what caused the LIA.? then explain what caused the LIA to finish. what natural factors ? then explain how those natural factors are still relevant now? i just want to check that you understand the subject. please include sources, hopefully peer reviewed ones. but not necessarily. i look forward to your explanation of how the LIA is effecting climate now
so smokey, you admit there has been a long term global warming trend since the LIA. bill would disagree with you. he says there was a cooling period from 1940 to 1965. and now he states that the last decade has seen no rise in temp. that means the LIA warming effect finished in 1940 according to bill? maybe you two should have a discussion to iron out your differences?
david brown says:
“”wood for trees” is not a scientific link smokey. and your graphs contains no information as to who is responsible for them. who is the research group who did the measurements and formulated the graphs?”
Mr brown is new here, but that does not excuse his ignorance. All of the WFT graphs contain the information about who provided the data; brown just didn’t bother to look. He just made an assumption, which, like his other assumptions, turned out to be wrong.
The rest of us know who is responsible for Wood For Trees [WFT]. It is a freeware site that uses empirical [real world] data provided by NASA GISS, HADcrut, RSS and UAH satellite data, CRUtem, HADSST2, NSIDC, MLO [Mauna Loa CO2], and other temperature and CO2 data that can be displayed and compared.
WFT automatically converts the data into graphs, which commenters use here all the time. Brown’s is the very first complaint of WFT that I have seen like that, and it displays his ignorance for all to see. I would suggest that brown try using the WFT site, but I honestly believe that his science education is inadequate.
Contrary to what brown says, WFT is real state of the art science. It is a valuable resource that is regularly used by both sides of the debate. Brown just doesn’t like it, because it debunks what he is trying to sell. The WFT graphs I posted show clearly and convincingly, based on real world measurements and observations, that the long term rise in temperature since the LIA remains within narrow parameters. Global temperatures are not accelerating, as the WFT charts show. Rather, they are rising at the same steady rate, despite the large increase in CO2. Brown doesn’t like that fact, but too bad. That’s reality.
smokey , you are pulling my leg . if wood for trees uses graphs from nasa why do they resemble nothing like nasa has on their website? they look amateur .why is their nothing identifying the original source ?why is there no detail. why do the wood graphs differ from the graphs nasa has on their website? why would these graphs refute agw when nasa endorses it? why not just go directly to the nasa website? and you still have not answered my questions about the LIA.
david brown,
You have nine more comments to go before you set a new record.☺
And since no one on either side of the debate has a problem with WFT — except for you – do you think everyone else is wrong, and you’re right? You sound like an eight year old pestering his mother with your endless questions. No one else cares that you can’t understand the WFT site, or how to use it.
Your questions are easy to answer. But you’re a pest, and you will remember the answers much better if you find them yourself. Start with the WUWT archives. Learn something for a change, instead of repeating stupid talking points and asking questions that display your ignorance. And learn how to post a hotlink. It isn’t hard.
in other words you do not know the answers smokey.? i know the answers i was just seeing if you did. and you do not. which means you have not fully researched the subject . .WFT is no substitute for NASA or the World Met
david brown,
You stated that ” ‘wood for trees’ is not a scientific link”, and then you went on to say that “your [WFT] graphs contains no information as to who is responsible for them.” FYI, NASA provides some of the WFT data. And please explain who the “World Met” is.
Your ignorance is on display. Every WFT graph lists exactly where the data came from. And the top of every WFT page lists detailed information on how to construct graphs from data. In particular, read the Notes page.
Now you are claiming that I don’t know the answers to the simple, inane questions you are always asking. But of course, I do. They are simpleton questions. You can get your answers in the WUWT archives. And the fact that you even ask those questions makes clear that you are a newbie and on the wrong track. Your responses exhibit monumental ignorance of the subject. Really, you sound like a very young know-nothing, who preposterously claims to know it all.
Since you claim to be so smart, exlpain why the long term temperature trend has not changed for hundreds of years – while during that time CO2 has increased from 280 ppmv to 392 ppmv. Explain why CO2 has had no measurable effect.
I have provided charts based on real world data and observations, showing definitively that there is no accelerated warming; it is an artefact of an arbitrary zero baseline chart, while you post cut ‘n’ paste nonsense based on always-inaccurate, repeatedly falsified computer models. Pay attention here: models are not scientific evidence. They are programmed opinion. GIGO: Garbage In, Gospel Out. Let’s stick with verifiable, testable evidence, per the scientific method. The claptrap you are posting is pseudo-science; models that cannot even hindcast! Get real.
In the case of NASA/GISS, they mendaciously “adjust” the temperature record, as you can see here, and here, and here, with no explanation. And their ‘adjustments’ always show a more alarming rise in temperature. What are the odds of that?? Only a fool would trust them or their data.
I am 64, retired after a 30+ year carreer in weather related instrument construction and calibration. Our Metrology Lab received all the professional literature from instrument manufacturers, gratis. So I have seen the alarmist narrative evolve from the global cooling scare to the global warming scare, and it is equally grant-based nonsense. What intrigues me is why someone like you would turn into a religious True Believer? What causes that?? It certainly is not scientific knowledge. You remind me of Winston Smith, who wondered: if everybody believes that 2 + 2 = 5, would that make it true? In your case, I think you would answer “Yes.”
david brown says:
July 8, 2012 at 1:50 pm
you are wrong bill i browsed the links you posted. but if their conclusions are that the planet is not warming. or that aerosols do not cool climate. or that the sun is not decreasing in activity and is not a forcing agent . then they have little credibility.
You said you browsed the links, but you have no idea what they said? Pardon me if I disbelieve that.
Since you seem to believe that the WMO is the ultimate authority on climate temperature trends – so try to wrap your mind around this: The WMO gets its data from the Hadley Climatic Research Unit (HadCRUT) in East Anglia. HadCRUT data *shows* that the global temperature has not been increasing —
http://wattsupwiththat.com/2012/04/28/tisdale-a-closer-look-at-crutem4-since-1975/
http://wattsupwiththat.com/2012/03/20/new-and-improved-crutem4-global-land-surface-temperature-data-vs-ipcc-ar4-cmip3-climate-models/
http://www.c3headlines.com/2012/04/connect-the-dots-global-warming-hadcrut-warming-turns-cooling.html
— yet the WMO, which has that exact same data, claims the temperature is increasing. So, who’s been lying to you – the Earth or the WMO?
@ur momisugly david brown I just saw Smokey’s comment to you — “Pay attention here: models are not scientific evidence. They are programmed opinion. GIGO: Garbage In, Gospel Out.”
Read the post at this link carefully, the charts can be confusing to someone whose first language isn’t English; they alternate — odd numbered charts show what the models predicted and even numbered charts show the actual observations.
http://wattsupwiththat.com/2012/03/20/new-and-improved-crutem4-global-land-surface-temperature-data-vs-ipcc-ar4-cmip3-climate-models/
bill, models for climate have been around for decades. more than enough time to confirm their reliability. and reliable they are. extreme weather, melting glaciers and ice caps, the warming of the oceans etc was predicted long ago. proving that models are reliable. obviously models for the future eg the impact of global warming if c02 levels double is speculative up to a point. who can predict the future with 100 percent accuracy .? . but going on the past, there is a good probability those models will be correct as well. models are based on research and the collecting of data and empirical observations. this all takes place ”before ” the models are formulated. models are not just made up as you seem to believe. i do not think you or smokey are qualified enough to question the science. smokey cannot even explain the premise of his argument about the LIA. and you do not know that the sun is a forcing agent.. he has never even heard of the World Meteorological Org. they have been around since 1854. that level of ignorance in inexcusable in a debate about climate. it is akin to not knowing who Newton was , when discussing gravity. it totally undermines smokey’s position . it shows he has done no research. he says the ”wood” people are ”interpreting” the data from nasa etc to construct their graphs. why not just rely on nasa? his only argument is that nasa is ”shady ” or cannot be trusted . a silly conspiracy . if nasa cannot be trusted why take their data to the wood org in the first place ? it is another contradiction .Hadcrut endorse the consensus on climate change. as does nasa, the world met and the royal society. are they all not to be trusted? what are your and smokey’s sources. name one major science group that endorses your position. you cannot. where are you models? who is collecting your data? if nasa cannot be trusted who can be? you do not have a leg to stand on. no sources, no endorsements. no real understanding of the science. and unsubstantiated conspiracy. it is not a good position to be in
bill, smokey said nasa cannot be trusted. and yet he takes their data to the ”wood ” people for interpretation, so they can construct their graphs. that makes no sense. he does not even know the premise of his own argument about the LIA. has no idea who the world meteorological org is. they have been around since for 1854. that shows he does not know the subject. you do not know that the sun is a forcing agent and yet you challenge the greatest scientific bodies on the planet. climate models are based on data and empirical observations. this is done ”before” the models are constructed. modelling has been around for 50 years are more. more than enough time to test their accuracy. science would not use the method if it was unreliable. going to the moon was based on a model of sorts. turned out to be pretty accurate. Hadcrut endorse the consensus on climate change by the way. as do every other major group. where are your sources? your data. who confirms your position?where are your models? you do not have much of an argument.
[Moderator’s Note: I was tempted to snip this for your own good, but that would have been counter-productive. You might have become better acquainted with WFT before denouncing it. You might have done a number of things. By the way, if your trip from Sydney to London back in May was via an American-made plane, it is very likely that Smokey’s efforts are what helped keep it in the air. As the Royal Navy once put it: “For what we are about to receive, may the Good Lord make us truly grateful.” -REP]
Thank you, Mr Moderator.
I’m moving on, this thread is four days old and almost no one is reading it any more. Some of us are still trying to educate david brown, but it isn’t working, sad to say.
So Mr brown can have the last word as a consolation prize for his abysmal scientific knowledge [I should point out that the World Meterological Organizations’ abbreviation is “WMO”, not “World Met”, which sounds like something from the Met Office].
Anyway, Mr brown, have a nice day on your planet, wherever it is.☺ Cheers.
Smokey says:
July 9, 2012 at 4:10 pm
Some of us are still trying to educate david brown, but it isn’t working, sad to say.
You can’t teach aerodynamics to someone who insists magic carpets are real…
mr moderator, you are supposed to be impartial.? smokey thinks i have abysmal scientific knowledge.? what i say comes from NASA and the CSIRO, so i think my knowledge is credible. needless to say, i do know what caused the LIA. and why the LIA could not be a factor now.i also know that the sun is a forcing agent. and also know that decreased solar activity cannot lead to increased natural warming. which is what mr tuttle and smokey think. i also know that the world met could not possibly mean ”world police force ”.i also see no need to take data from nasa too another party [ non scientific ] for graph construction. nasa has its own graphs, as does the world met. i suggest smokey study them. as for keeping my plane in the air? if id known smokey had anything to do with it, i would not have boarded. and smokey i am from planet earth. and that planet continues to warm. thanks mr moderator. i have enjoyed our little tussle. albeit rather pointless. may you receive a little knowledge on the subject of climate science. for that, we will all be truly grateful
Bill Tuttle. To educate first you must know. And Mr Moderator. i have not flown in three years .And certainly not from Sydney
bill, aerodynamics is endorsed by every major group involved in flight research . there is a world wide consensus what makes aircraft fly and what makes them crash. in other words you must ”appeal to authority” to get the correct answers. what you are proposing in regard to climate change does not have similar endorsements. no major science group endorses your position.if you were involved in aerodynamics your planes would not get off the ground. and magic carpet rides do not come with with a physics equation or empirical observations. AGW does. this is my last comment. i have enjoyed it. goodbye mr moderator.i hope you learn the meaning of impartiality soon?