Global dimming and brightening: A review
Martin Wild
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
There is increasing evidence that the amount of solar radiation incident at the Earth’s surface is not stable over the years but undergoes significant decadal variations. Here I review the evidence for these changes, their magnitude, their possible causes, their representation in climate models, and their potential implications for climate change. The various studies analyzing long-term records of surface radiation measurements suggest a widespread decrease in surface solar radiation between the 1950s and 1980s (“global dimming”), with a partial recovery more recently at many locations (“brightening”). There are also some indications for an “early brightening” in the first part of the 20th century. These variations are in line with independent long-term observations of sunshine duration, diurnal temperature range, pan evaporation, and, more recently, satellite-derived estimates, which add credibility to the existence of these changes and their larger-scale significance.
Current climate models, in general, tend to simulate these decadal variations to a much lesser degree. The origins of these variations are internal to the Earth’s atmosphere and not externally forced by the Sun. Variations are not only found under cloudy but also under cloud-free atmospheres, indicative of an anthropogenic contribution through changes in aerosol emissions governed by economic developments and air pollution regulations. The relative importance of aerosols, clouds, and aerosol-cloud interactions may differ depending on region and pollution level. Highlighted are further potential implications of dimming and brightening for climate change, which may affect global warming, the components and intensity of the hydrological cycle, the carbon cycle, and the cryosphere among other climate elements.
Received 14 November 2008; accepted 10 March 2009; published 27 June 2009.
Citation: Wild, M. (2009), Global dimming and brightening: A review,
J. Geophys. Res., 114, D00D16, doi:10.1029/2008JD011470.
I found this passage that parallels a lot of what I’ve been saying about data quality:
The assessment of the magnitude of these SSR (surface solar radiation) variations faces a number of challenges. One is related to data quality. Surface radiation networks with well-calibrated instrumentation and quality standards as those defined in BSRN [Ohmura et al., 1998] need to be maintained on a long-term basis and if possible expanded into underrepresented regions (see Figure 1b).
However in this figure, citing CRU surface temperature, he likely doesn’t understand what data quality issue might have contributed to the trend from 1960-2000
One of the effects of urbanization is the compression of the diurnal temperature variation. I recently was able to demonstrate this between two stations in Honolulu. One is in the middle of the Airport and had a sensor problem, the other was in a more “rural” setting about 4 miles away. Note how the ASOS station at the airport has an elevated temperature overall, but that the biggest difference occurs in the overnight lows, even when the ASOS sensor giving new record highs was “fixed”:
Urbanization affects Tmin more than Tmax. For example, here’s the nighttime UHI signature of Reno, NV that I drove as a measurement transect using a temperature datalogger:
Click for larger image
Even several hours after sunset, at 11:15PM, the UHI signature remained. The net result of urbanization is that it increases Tmin more than Tmax, and thus minimizes the diurnal range, which we see in Wild’s diurnal range graph.
Even the IPCC misses it:
Wild probably has no idea of this type of issue in the CRU data, but again it speaks to data quality which he seems to be keen on. He’s looking for a global solar signature in temperature data, something Basil Copeland and I have done, to the tune of much criticism. The signature is there, but small. But, when diurnal temperature variation is looked at, any solar signature is likely swamped by the urbanization signal. I’m not saying there is no solar component to what Wild is looking at, but it seems fairly clear that UHI/urbanization/land use change plays a significant role also.
Even rural stations can be affected by our modern society, as Dr. John Christy demonstrated in California’s central valley:
A two-year study of San Joaquin Valley nights found that summer nighttime low temperatures in six counties of California’s Central Valley climbed about 5.5 degrees Fahrenheit (approximately 3.0 C) between 1910 and 2003. The study’s results will be published in the “Journal of Climate.”
The study area included six California counties: Kings, Tulare, Fresno, Madera, Merced and Mariposa.
While nighttime temperatures have risen, there has been no change in summer nighttime temperatures in the adjacent Sierra Nevada mountains. Summer daytime temperatures in the six county area have actually cooled slightly since 1910. Those discrepancies, says Christy, might best be explained by looking at the effects of widespread irrigation.
Wild’s study is a very interesting and informative paper, I highly recommend reading the entire paper here (PDF 1.4 mb)
h/t and sincere thanks to Leif Svalgaard for bringing this paper to my attention.
General suggestion about site:
Have the most recent comment posted at the top rather than the bottom of the list. Will provide a much better flow.
Regards
I remember seeing a BBC documentary years ago on global dimming and how it was masking global warming and how global warming was much worse than anyone taught. It suggested jet contrails were causing cooling but quick bit of research says the opposite.
“Jet Contrails Alter Average Daily Temperature Range”
http://www.sciencedaily.com/releases/2002/08/020808075457.htm
“NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994.”
ttp://www.sciencedaily.com/releases/2004/04/040428061056.htm
While i am here a bit off topic but interesing also:
http://www.newscientist.com/article/mg20227144.700-sun-leaves-earth-wide-open-to-cosmic-rays.html
The “dimming” hypothesis is central to the claim that models properly simulate the 20th century climate, and thus the attribution of warming to CO2. Aerosols are chosen to have time histories and magnitudes as needed to match the temps in models. Now it likely seems that this alleged canceling factor which “explains” why the warming has been less than models would predict with their high sensitivities, appears to be disappearing…but not accompanied by a ramp up in warming.
Good points about the Diurnal temperature range. The failure of models in this regard is strong evidence that they are failing to account for the influence of land use changes. More over, mean temps that models are supposed to get right are just the average of max and min. If you get the mean right but the max and min wrong, then the “match” is nothing but a COINCIDENCE. Case closed.
Oh my God! That solar irradiance at the surface is out of control, someone call Congress and tell them to turn down the sun!!! (sarcasm off)
If you have the time to waste here is the documentary i refered to in my last comment
There is much that can vary the total amount of solar radiation reaching the ground. Things such as cloud cover and even prevailing winds can locally impact total solar energy reaching the surface.
It shouldn’t be all that difficult to build a sensor array that is responsive to a wide range of wavelengths and simply measure the amount of radiation reaching the sensor. But I would hesitate to extrapolate a local reading into a global proxy. Changes in dust and other particulates, changes in oxides of sulphur, and changes in cloud cover can influence local readings at a specific place but may have no relation to things happening on a global scale.
Now, having finished jabbering, I will go and actually read the paper 🙂
A 20% change in surface radiation from the sun seems significant to me (because I’m no solar scientist). I hope Leif has a few comments on surface radiation.
Two comments:
1. Figure 4 in the paper begs for oceanic and trade wind oscillation analysis. I would bet that correlations can be found. Notice where the trends lay. The paper makes the mistake of averaging surface brightness along arbitrary lines without considering natural weather pattern variation dictated by local and regional trade wind and oceanic oscillations. It would have been better to separate out each area based on the affects of nearby trade wind and oceanic oscillations to sensor location. For example, while the PDO was up and the SOI was down, brightness would be more instructive if separated out into two graphs, that is, measures taken by sensors in and around surface areas affected by the PDO, and surface areas affected by the SOI. Averaging them together potentially covers up important regional weather pattern variation drivers, thus surface radiation, leading to potential false positive or false negative conclusions by the author.
2. Aerosols may be more related to drought and precipitation cycles causing natural atmospheric dust to wax and wane on a decadal scale as a result of oceanic oscillation affects, and less by pollution.
Some here are confusing irradiation with radiance. One is surface solar irradiance of the Sun’s surface as measured by instruments outside Earth’s atmosphere and pointed at the Sun, and demonstrates only tiny variation. The other is surface solar radiance reflected from Earth’s surface through its lower atmosphere as measured by instruments inside Earth’s atmosphere as well as by satellites, pointed at Earth, and thus demonstrates quite a bit of variation. In other words, surface solar irradiance is an exogenous source of variation which is so tiny as to be buried in Earth’s data noise. Surface solar radiance is an endogenous source of variation with a signal that is easily extrapolated from Earth’s data noise.
RE Global dimming on the BBC:
This is an example of how AGW and its obsession on CO2 is killing us.
Treating CO2 as a pollutant, which it is not, has been coming at the expense of reducing real pollutants and toxins.
Mark (11:58:47) :
A 20% change in surface radiation from the sun seems significant to me (because I’m no solar scientist). I hope Leif has a few comments on surface radiation.
What the Sun puts out varies only one in a thousand. What reaches the ground varies a hundred times as much and that variation is thus hardly due to the Sun, which I think is a central point of the paper.
Does anyone know where we can read the actual text of the bill as it was adopted by congress yesterday? Thanks.
Is Doug Hoyt out there? Please comment.
http://www.climateaudit.org/?p=755
Douglas Hoyt:
July 22nd, 2006 at 5:37 am
Measurements of aerosols did not begin in the 1970s. There were measurements before then, but not so well organized. However, there were a number of pyrheliometric measurements made and it is possible to extract aerosol information from them by the method described in:
Hoyt, D. V., 1979. The apparent atmospheric transmission using the pyrheliometric ratioing techniques. Appl. Optics, 18, 2530-2531.
The pyrheliometric ratioing technique is very insensitive to any changes in calibration of the instruments and very sensitive to aerosol changes.
Here are three papers using the technique:
Hoyt, D. V. and C. Frohlich, 1983. Atmospheric transmission at Davos, Switzerland, 1909-1979. Climatic Change, 5, 61-72.
Hoyt, D. V., C. P. Turner, and R. D. Evans, 1980. Trends in atmospheric transmission at three locations in the United States from 1940 to 1977. Mon. Wea. Rev., 108, 1430-1439.
Hoyt, D. V., 1979. Pyrheliometric and circumsolar sky radiation measurements by the Smithsonian Astrophysical Observatory from 1923 to 1954. Tellus, 31, 217-229.
In none of these studies were any long-term trends found in aerosols, although volcanic events show up quite clearly. There are other studies from Belgium, Ireland, and Hawaii that reach the same conclusions. It is significant that Davos shows no trend whereas the IPCC models show it in the area where the greatest changes in aerosols were occurring.
There are earlier aerosol studies by Hand and in other in Monthly Weather Review going back to the 1880s and these studies also show no trends.
So when MacRae (#321) says: “I suspect that both the climate computer models and the input assumptions are not only inadequate, but in some cases key data is completely fabricated – for example, the alleged aerosol data that forces models to show cooling from ~1940 to ~1975. Isn’t it true that there was little or no quality aerosol data collected during 1940-1975, and the modelers simply invented data to force their models to history-match; then they claimed that their models actually reproduced past climate change quite well; and then they claimed they could therefore understand climate systems well enough to confidently predict future catastrophic warming?”, he close to the truth.
_____________________________________________________________________
Douglas Hoyt:
July 22nd, 2006 at 10:37 am
Re #328
“Are you the same D.V. Hoyt who wrote the three referenced papers?” Yes.
“Can you please briefly describe the pyrheliometric technique, and how the historic data samples are obtained?”
The technique uses pyrheliometers to look at the sun on clear days. Measurements are made at air mass 5, 4, 3, and 2. The ratios 4/5, 3/4, and 2/3 are found and averaged. The number gives a relative measure of atmospheric transmission and is insensitive to water vapor amount, ozone, solar extraterrestrial irradiance changes, etc. It is also insensitive to any changes in the calibration of the instruments. The ratioing minimizes the spurious responses leaving only the responses to aerosols.
I have data for about 30 locations worldwide going back to the turn of the century.
Preliminary analysis shows no trend anywhere, except maybe Japan.
There is no funding to do complete checks.
__________________________________________
Leif, thanks for the link to the paper.
Figure 7 in the Wild (2009) paper is telling. It illustrates how well(?) current climate models simulate surface solar radiation. Wild could have saved a lot of time typing Section 5 of his report by answering the question in the section title (How Do Current Climate Models Simulate Global Dimming/Brightening?) with one word: Poorly.
Poorly is also the single-word description of how GCMs model ENSO.
In the concluding remarks, I also found the wording of the first few sentences in paragraph 127 (page 27/31) interesting.
“The origin of dimming/brightening has shown to be
internal to the climate system and not externally forced by
the Sun. The main causes appear to be changes in cloud and
aerosol characteristics and abundance, which MAY OR MAY NOT be microphysically linked. EVIDENCE for an anthropogenic
contribution through emission changes and associated
modification of atmospheric aerosol loads HAS BEEN PRESENTED.” [My caps.]
Not very definite.
A two-year study of San Joaquin Valley nights found that summer nighttime low temperatures in six counties of California’s Central Valley climbed about 5.5 degrees Fahrenheit (approximately 3.0 C) between 1910 and 2003.
It’s a general misconception that Tmin occurs at night. It doesn’t. It typically occurs some time after dawn that varies with season and lattitude.
Jonathan at the blog, a Gust of Hot Air, did detailed analysis of Australian time based temperature data (available for many locations) and found something interesting.
He found that, at most locations, increasing Tmin wasn’t due to increasing nighttime temperatures, but was due to an earlier (in the morning) Tmin.
Something was causing a trend to more early morning warming and it was hard to avoid the conclusion it was less low cloud (near the horizon in the early morning) or less near ground haze, dust or mist.
Which is consistent with the global brightening/dimming analysis above. And points to decreasing industrial and vehicle particulate pollution causing increasing Tmin, and as increasing Tmin is most of the warming in global warming, the phenomena of global warming itself.
Leif:”What the Sun puts out varies only one in a thousand. What reaches the ground varies a hundred times as much and that variation is thus hardly due to the Sun, which I think is a central point of the paper.”
Except of course if it is the sun’s magnetic field’s effect on cosmic rays which cause changes in low level cloudiness. This would put a large gain on the effects of the sun.
I saw that BBC documentary on global dimming as well. There was this climate scientist, Dr Cox (can’t remember from which university) telling viewers that because global dimming was masking the warming effects of CO2, then the AGW temperature sensitivity is actually twice as great as previously thought. No evidence was given for this statement, which went unchallenged by the makers of the film. Dr Cox then produced the current curve of temperature increases as prophesied by the GCM, showing the anomaly of +5 C by 2100, and drew the new corrected line by doubling the original gradient. Result: +10c. Incredibly, this was then followed by a computer generated film showing London rendered under a sub saharan climate, complete with orange dust storms, like a scene from Herbert Spencer;s Dune. Incredibly, the narator then proceeded to warn, in a sombre voice that “this will happen – unless . . .” Note the use of the phrase ‘Will’, not ‘could’, or ‘may’ happen.
Remembering how Global Warming Swindle was attacked for far less, the hypocricy on this stinks.
Allan M R MacRae (13:38:13) :
“So when MacRae (#321) says: “I suspect that both the climate computer models and the input assumptions are not only inadequate, but in some cases key data is completely fabricated – for example, the alleged aerosol data that forces models to show cooling from ~1940 to ~1975. Isn’t it true that there was little or no quality aerosol data collected during 1940-1975, and the modelers simply invented data to force their models to history-match; then they claimed that their models actually reproduced past climate change quite well; and then they claimed they could therefore understand climate systems well enough to confidently predict future catastrophic warming?”, he close to the truth.”
Would you provide proof of your “the modelers simply invented data” claim? For example, show that the sulfate aerosol forcing data that the IPCC AR4 models used was “invented”, by whom, and how.
Extraordinary claims demand extraordinary evidence; please provide some.
I was casually comparing the first chart in the article with this one: click, to see what I could see. Maybe notice a little correlation.
Not a lot of correlation, but the more I looked at the raw data, the more it looks like global warming since the 1950’s is mostly an artifact of data adjustments.
Looking at the illustration for diurnal temperature range (DTR), I am struck by the reduction in the DTR since the 60’s. It suggests to me that the UHI effect is overwhelming data from more pristine rural stations as the number of such rural locations have dramatically dropped off over the years. It says less about the climate and more about the data quality. It seems that this point is also echoed in Dr. Christy’s land use study, which was reported on in 2007, and cited in the article above.
This reminded me of the article of a good station in Tucumcari, NM (rated CRN2) where a warming bias was discovered in the Tmin after 2000, a result of land use change – irrigation.
http://wattsupwiththat.com/2008/06/30/whos-adjusting-the-climate-in-tucumcari-cows-canals-or-hansen/
As the surfacestations project has demonstrated so many times, there’s more to the study of climate than massaging data on a computer; you need lots of field work to validate the data (protesting at a coal-fired electricity generating facility does not constitute field work).
Tom, the bill HR 2454 is available at LOC – http://thomas.loc.gov/cgi-bin/bdquery/D?d111:24:./temp/~bdwaHD:: Click on “Text of Legislation” for the whole monster. Also has related bills, amendments, etc.
Gary Strand (14:48:17) : That aerosol forcings are “pulled out of a hat” to use Hansen’s words is well known. Kiehl (2007) showed that the choice of aerosols forcings to use in 20th century model runs depends on the climate sensitivity… IOW, The data are MADE UP-whatever it takes to get the models to match. Fraud? Value judgment. Fudging? Yes.
http://www.climateaudit.org/?p=2475
http://www.columbia.edu/~jeh1/2009/Copenhagen_20090311.pdf
Leif Svalgaard (16:17:53) :
Mike Borgelt (14:10:16) :
Except of course if it is the sun’s magnetic field’s effect on cosmic rays which cause changes in low level cloudiness. This would put a large gain on the effects of the sun.
Except of course that the cosmic rays and the albedo as measured do not show any significant correlation, and also that cosmic rays to within one percent have been the same at all solar minima we have good data for [since 1951 or so] while the temperature [and presumably the low clouds and the albedo] has not.
The Aerosols forcing data that GISS uses is entirely artificial.
Here it is. [This is the annual data. The monthly Aerosols forcing varies a little bit but since the annual data is so linear, it is clear the monthly data is artificial as well.]
http://img58.imageshack.us/img58/855/modelaerosolsforcingp.png
And this is how Aerosols impacts temperatures (-0.6C as of 2003) compared to the other “forcings” [interesting that forcing and artificial have similar meanings in certain cases].
http://img509.imageshack.us/img509/8388/modeletempimpactst.png
RE first graph (“Fig. 2”), how can a 5-year MA extend beyond the first and last annual observation plotted? There appears to be no annual data before 1923 or after 2000.
A strict 5-year MA would begin and end 2 years inside the end points, though some might reasonably truncate the filter at the ends to give the average of the first and last 3 annual observations. (Michael Mann’s double-flip method would effectively end-peg to the last observation, but even he would not project beyond the last point, I hope.)
For those who haven’t seen the documentary on Henrik Svensmark’s finding on aerosols and cosmic rays here is the first of a five part YouTube series.
Leif Svalgaard (17:06:48) :
Leif Svalgaard (16:21:13) :
perhaps a nice moderator would just FIX this…
Ah, well, he didn’t…
[Reply: Please be more specific, Leif. What exactly would you like fixed? ~ dbstealey, moderator]
That Leif Svalgaard (16:17:53) : be changed as shown below
and that
Leif Svalgaard (16:18:43) :
Leif Svalgaard (16:21:13) :
Leif Svalgaard (17:06:48) :
be removed, thanks.
———————————-
Leif Svalgaard (16:17:53) :
Mike Borgelt (14:10:16) :
Except of course if it is the sun’s magnetic field’s effect on cosmic rays which cause changes in low level cloudiness. This would put a large gain on the effects of the sun.
Except of course that the cosmic rays and the albedo as measured do not show any significant correlation, and also that cosmic rays to within one percent have been the same at all solar minima we have good data for [since 1951 or so] while the temperature [and presumably the low clouds and the albedo] has not.
[Reply: Done. ~dbs]
I wonder what would happen if the forcing from the brightening/dimming on global temps. was removed from the record, would we have less amount of a warming trend over the 20th century?
Meanwhile we’re just getting over our first extended heatwave here, the amazing part is that out of 5 days here in Wichita they were predicting to hit or pass 100 degrees, we only had one 100 degree day as temps. fell short of the forecast and hit 97-99 degrees instead. In fact total no. of stations with 100 degree readings in Kansas seemed to be a bit less than what was forecast, maybe partly thank the Sun which it seems to be dimming and not because of pollution. 🙂
Leif Svalgaard (17:43:07) :
[Reply: Done. ~dbs]
thanks, and then remove 17:43:07 and this one too.
hot off the press regarding Jim Hansen
http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=1a5e6e32-802a-23ad-40ed-ecd53cd3d320
Tim (18:03:46) : hot off the press regarding Jim Hansen
I don’t think that an entry from January 27, 2009 is “Hot Off the Press”.
Dr. Theon being a skeptic and his comments about Hansen are old hat by now.
Leif Svalgaard (16:17:53) :
Mike Borgelt (14:10:16) :
“Except of course if it is the sun’s magnetic field’s effect on cosmic rays which cause changes in low level cloudiness. This would put a large gain on the effects of the sun.
Except of course that the cosmic rays and the albedo as measured do not show any significant correlation, and also that cosmic rays to within one percent have been the same at all solar minima we have good data for [since 1951 or so] while the temperature [and presumably the low clouds and the albedo] has not.”
Except of course we can experimentally test short term correlations say with Forbush decreases.
Pudovkin, M. I. and Veretenenko, S. V.: Cloudiness decreases associated with Forbush decreases of galactic cosmic rays, J. Atmos. Sol.-Terr. Phy., 57, 1349–1355, 1995.
Tim (18:03:46) :
Hot off the press? January 27th?
OT, but being as Adam from Kansas (17:55:41) was not snipped:
June 27, 2009 San Antonio Express-News
The lingering heat wave on Friday obliterated a high temperature record that had stood since 1980.
The 103 reading surpassed the 102 mark set 29 years ago, according to the National Weather Service, which predicts similar readings at least through Sunday.
Authorities said more than 80 people have been treated for heat-related illnesses so far in June around San Antonio, where temperatures have reached 100 degrees nine times this month, but no heat-related deaths have been reported.
maksimovich (18:43:52) :
Leif Svalgaard (16:17:53) :
Mike Borgelt (14:10:16) :
“Except of course if it is the sun’s magnetic field’s effect on cosmic rays which cause changes in low level cloudiness. This would put a large gain on the effects of the sun.
Except of course that the cosmic rays and the albedo as measured do not show any significant correlation, and also that cosmic rays to within one percent have been the same at all solar minima we have good data for [since 1951 or so] while the temperature [and presumably the low clouds and the albedo] has not.”
Except of course we can experimentally test short term correlations say with Forbush decreases.
Pudovkin, M. I. and Veretenenko, S. V.: Cloudiness decreases associated with Forbush decreases of galactic cosmic rays, J. Atmos. Sol.-Terr. Phy., 57, 1349–1355, 1995.
and when we do [note publication date 2008]:
Cosmic rays, cloud condensation nuclei and clouds – a reassessment using MODIS data
Kristjánsson, J. E. et al.
Atmospheric Chemistry and Physics, Volume 8, Issue 24, 2008, pp.7373-7387
The response of clouds to sudden decreases in the flux of galactic cosmic rays (GCR) – Forbush decrease events – has been investigated using cloud products from the space-borne MODIS instrument, which has been in operation since 2000. By focusing on pristine Southern Hemisphere ocean regions we examine areas where we believe that a cosmic ray signal should be easier to detect than elsewhere. While previous studies have mainly considered cloud cover, the high spatial and spectral resolution of MODIS allows for a more thorough study of microphysical parameters such as cloud droplet size, cloud water content and cloud optical depth, in addition to cloud cover. Averaging the results from the 22 Forbush decrease events that were considered, no statistically significant correlations were found between any of the four cloud parameters and GCR, when autocorrelations were taken into account. […]
Confident as ever Leif. David Stockwell looked into that paper and said that he thinks that the paper is “schizophrenic”:
http://landshape.org/enm/cosmic-rays-cloud-condensation-nuclei-and-clouds-%E2%80%93-a-reassessment-using-modi-data/
Because their claims of “insignificance” appear to be belied by their own tables etc.
But such a limited study can hardly be used to definitively reach such broad conclusions. I know you are skeptical of most solar-climate stuff, but you might want to avoid jumping on papers that reinforce those perceptions!
Does anybody know this: Assuming Svensmark is correct and Cosmic ray burst etc are distributed equally over the hemisphere, there should be a correlation between clouds and cosmic ray count? Maybe the bursts hit some areas more than other? In this case hard to correlate? Hasn’t this been done?
Re Svensmark Sorry just saw previous post question answered. What a coincidence!
Leif,
From my reading not all GCRs are equal. Svensmark does address the issue of Forbush events in his work. He indicates that the events are short lived and often not powerful enough to deflect muons. I do not feel that a study based on Forbush events is sufficient to dismiss the GCR/cloud hypothesis. The CLOUD experiment is designed to look at the interaction of muons, near ocean surface air chemistry and UV radiation. I believe that the controlled experiment at CERN is most appropriate way to investigate this matter. I am wary of attempts to dismiss the hypothesis through computer modelling or observations during Forbush events of limited duration and variable effect. For better answers we will just have to wait on results from the physical experiment.
Having said that, I would not be surprised if the role of muons in cloud nucleation turns out to be just one of Jack Eddy’s “many plugs”.
timetochooseagain (19:50:06) :
Because their claims of “insignificance” appear to be belied by their own tables etc.
What this just shows is that it has not been established that there is a significant correlation. You don’t see papers anymore trying to show that geomagnetic storms come from the Sun. That is because that has been established.
Konrad (20:58:33) :
From my reading not all GCRs are equal. Svensmark does address the issue of Forbush events in his work. He indicates that the events are short lived and often not powerful enough to deflect muons.
maksimovich (18:43:52) was using Forbush events to ‘test’ the stuff. doesn’t this cut both ways? Or maybe not: if something supports a hypothesis it is good, if it does not, then it is ‘not powerful enough’.
Muons are created in the atmosphere and are not ‘deflected’.
I’m not saying that there is no effect. What I’m saying is that it has not been established that there is an effect. Anybody is free to speculate as he/she wants, as long as it is labeled as such. But, the GCR effect has almost become as much dogma as AGW, just with the opposite sign.
Instead of looking for correlations, one can try to use physics to address the efficiency of the process of GCRs:
Can cosmic rays affect cloud condensation nuclei by altering new particle formation rates?
Pierce, J. R.; Adams, P. J.
Geophysical Research Letters, Volume 36, Issue 9, CiteID L09820, 05/2009
“Although controversial, many observations have suggested that low-level cloud cover correlates with the cosmic ray flux. Because galactic cosmic rays have likely decreased in intensity over the last century, this hypothesis, if true, could partly explain 20th century warming, thereby upsetting the consensus view that greenhouse-gas forcing has caused most of the warming. The “ion-aerosol clear-air” hypothesis suggests that increased cosmic rays cause increases in new-particle formation, cloud condensation nuclei concentrations (CCN), and cloud cover. In this paper, we present the first calculations of the magnitude of the ion-aerosol clear-air mechanism using a general circulation model with online aerosol microphysics. In our simulations, changes in CCN from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties; consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change.”
—————
I know that people will shout MODEL only, thus LIES. But read the paper and see that this is a different [good] kind of model, i.e. not the climate models that pretend to forecast a hundred years ahead the effect of a butterfly beating its wings.
Anyway, I have not seen a convincing demonstration of the GCRs being a significant climate driver. Not that there are not many claims of that. It is almost so that the more claims there are, the less likely it is that they are true. [why keep trying to show that something is true when it has already been established?]
When I grew up in Sacramento, the largest common diurnal range was 45 degrees.
I was a bit shocked to see older records in a rural area topping 60 degrees diurnal range.
The change happened over a period of twenty years or so. Well before WWII.
Leif Svalgaard (19:31:38) :
“and when we do [note publication date 2008]:
Cosmic rays, cloud condensation nuclei and clouds – a reassessment using MODIS data
Kristjánsson, J. E. et al.
Atmospheric Chemistry and Physics, Volume 8, Issue 24, 2008, pp.7373-7387 ”
Yes I thought you would use that argument,hence use of way back machine and how Pudovkin has withstood the test of time eg
SOLAR ACTIVITY, COSMIC RAYS AND CLIMATE CHANGE
(ON THE 75TH ANNIVERSARY AND IN MEMORY OF PROF. M.I. PUDOVKIN )
O.M. Raspopov, S.V. Veretenenko 2009
Abstract. A review of the research activity of M.I.Pudovkin, his co-workers and followers in solving the problem of the solar activity influence on atmospheric processes and climate change is presented, the roles of cosmic ray variations and changes in cloudiness are emphasized. The problems that still remain unresolved in this field are outlined.
Kristjansson um tends to overlook his eastern neighbours hence he is able to use ” average”assumptions eg
‘Averaging the results from the 22 Forbush decrease events that were considered,
no statistically significant correlations were found between any of the four cloud parameters and GCR, when autocorrelations were taken into account.’
Linear approximation in a non-linear world eg
Empirical evidence for a nonlinear effect of galactic cosmic rays on clouds 2006
BY R. GILES HARRISON* AND DAVID B. STEPHENSON
Galactic cosmic ray (GCR) changes have been suggested to affect weather and climate, and new evidence is presented here directly linking GCRs with clouds. Clouds increase the diffuse solar radiation, measured continuously at UK surface meteorological sites since 1947. The ratio of diffuse to total solar radiation—the diffuse fraction (DF)—is used to infer cloud, and is compared with the daily mean neutron count rate measured at Climax, Colorado from 1951–2000, which provides a globally representative indicator of cosmic rays. Across the UK, on days of high cosmic ray flux (above 3600!102 neutron counts hK1, which occur 87% of the time on average) compared with low cosmic ray flux, (i) the chance of an overcast day increases by (19G4) %, and (ii) the diffuse fraction increases by
(2G0.3) %. During sudden transient reductions in cosmic rays (e.g. Forbush events),
simultaneous decreases occur in the diffuse fraction. The diffuse radiation changes are, therefore, unambiguously due to cosmic rays. Although the statistically significant nonlinear cosmic ray effect is small, it will have a considerably larger aggregate effect on longer timescale (e.g. centennial) climate variations when day-to-day variability averages out.
An important aspect of this is the dynamical aspects say in solar eg A. N. Gruzdev et al.: Effect of solar rotational variation on the atmosphere 2009
“In the extratropical latitudes, the responses are, in general,seasonally dependent. The sensitivity is in many cases stronger in winter than in summer. This has also been observed e.g. by Ruzmaikin et al. (2007) and is a hint to a possible
dynamical response to 27-day solar forcing. To clearly identify such a response, further analysis is needed.
Experiments with different forcing amplitudes have shown that the responses of temperature and of the concentrations of chemical species to 27-day forcing are non-linear. Their sensitivities (not amplitudes) generally decrease when the forcing
increases. This conclusion is important to understand the possible differences of observational studies obtained at times of different forcing amplitudes.”
Which allows us to return to FD attenuation(note publication 2009)
The effects of Forbush decreases on Antarctic climate variability: a
re-assessment
B. A. Laken and D. R. Kniveton
Abstract
In an attempt to test the validity of a relationship between Galactic cosmic rays (GCRs) and cloud cover, a range of past studies have performed composite analysis based around Forbush decrease (FD) events. These studies have produced a range of conflicting results, consequently reducing confidence in the existence of a GCR-cloud link.
A potential reason why past FD based studies have failed to identify a consistent relationship may be that the FD events themselves are too poorly defined, and require calibration prior to analysis. Drawing from an initial sample of 48 FD events taken from multiple studies this work attempts to isolate a GCR decrease of greater magnitude and coherence than has been demonstrated by past studies. After this calibration composite analysis revealed increases in high level (10–180 mb) cloud cover (of 20%) occurred over the Antarctic plateau in conjunction with decreases in the rate of GCR flux during austral winter (these results are broadly opposite to those of past studies).The cloud changes occurred in conjunction with locally significant surface level air temperature increases over the Antarctic plateau (4 K) and temperature decreases over the Ross Ice Sheet (8 K). These temperature variations appear to be indirectly linked to cloud via anomalous surface level winds rather than a direct radiative forcing. These results provide good evidence of a relationship between daily timescale GCR variations and Antarctic climate variability.
maksimovich (21:55:35)
(Memo to self include links)
http://www.atmos-chem-phys-discuss.net/9/10575/2009/
The effect of the solar rotational irradiance variation on the middle
and upper atmosphere calculated by a three-dimensional
chemistry-climate model
A. N. Gruzdev1, H. Schmidt2, and G. P. Brasseur3
http://www.atmos-chem-phys.net/9/595/2009/
One important note is the FD and say 27 day rotation allow us to “test” the qualities of the science in shorter time scales,and if we can see various “mechanisms” at work.
maksimovich (21:55:35) :
Yes I thought you would use that argument,hence use of way back machine and how Pudovkin has withstood the test of time eg…
As I said, there is no lack of claims and counterclaims.
Leif,
Yes I stand corrected, muons are created within the atmosphere. Svensmark actually was referring to the limited ability of some Forbush events to deflect muon creating particles (page 206 The Chilling Stars.) The ambiguity and variability of results from studies involving Forbush events seems to confirm Svensmark’s claim that cloud observations during these events are unlikely to prove or disprove the hypothesis.
Like yourself, I would say that I have not yet seen a convincing demonstration of GCR flux driving climate. I do not know if Svensmark is right. I do know he is doing the right thing in conducting physical experiments. Are those dismissing the hypothesis using Forbush studies or computer modeling prior to the results of a high quality physical experiment doing the right thing?
Well, Leif, the summer here in Greece so far reminds me of month October…rain, clouds & cold that were unseen around this area before.
So because solar radiation has been decreasing since about 1945, does this discredit the theory that the sun has had anything to do with earth’s global warming for the last 65 years?
Konrad (22:38:36) :
Are those dismissing the hypothesis using Forbush studies or computer modeling prior to the results of a high quality physical experiment doing the right thing?
Are the ones that use Forbush studies in support of the hypothesis doing the right thing? In both cases I would say “yes”, because the are many facets to this and it pays to look at them. It is not clear to what degree the ‘high quality’ experiment will be even applicable. I’m sure if it turns out negative that the supporters will claim that perhaps this was not a good test after all because of the difference of scale or some such.
the_Butcher (22:43:27) :
Well, Leif, the summer here in Greece so far reminds me of month October…rain, clouds & cold that were unseen around this area before.
Perhaps wearing a tin-hat to protect against cosmic rays may keep your brain from freezing up 🙂
Leif,
By high quality I was referring to the improvements over SKY 1 and 2. Also they are no longer stuck in the basement or the bottom of a coal mine. Particle physics in a shirt sleeve environment! But I may be being distracted by the shiny factor, as in – Hey they’ve got a big shiny cloud tank! I bet all the other scientists are jealous! 🙂
Konrad (23:37:36) :
By high quality I was referring to the improvements over SKY 1 and 2.
Why upgrade? Was the outcome of SKY 1 & 2 not what they wanted to see?
Leif,
I think it was always expected that SKY 1 and 2 would not be able to fully test the hypothesis. It should be remembered that CLOUD was proposed before SKY was built. It is clear the SKY experiments did get promising enough results to justify the expenditure on CLOUD, with greater beam time at CERN and a bigger shiny tank.
Leif Svalgaard (21:30:47) :
Not that there are not many claims of that. It is almost so that the more claims there are, the less likely it is that they are true. [why keep trying to show that something is true when it has already been established?]
Too tempting a dictum : I will repeat about tree rings. Science wisdom has it that the 11 year sun cycle was discovered in the change of the width of tree rings in cycles. If this is not a “science myth” it means that the climate changes with the cycles enough to be registered by the trees.
Are you aware of a publication that refutes this, or is the scarcity of publication in the google search a proof of your dictum “something is true so no need to establish it”?
Secondly, on the subject of cosmic rays, there is a publication that connects C14 with solar cycles http://cc.oulu.fi/~usoskin/personal/nature02995.pdf and sunspot counts :
For the Holocene, there is no evidence of considerable oceanic variability,
so we can assume that the short- and mid-term fluctuations of
14C predominantly reflect solar variability. This is supported by the
strong similarity of the fluctuations of 10Be in polar ice cores
compared to 14C, despite their completely different geochemical
history18–20.
from a news release blurb:
The new method works like this: Trees and tree rings contain carbon, which they get from carbon dioxide in the atmosphere. Some of that carbon is the isotope carbon-14 which is created in the Earth’s atmosphere by cosmic rays flying in from outside the solar system.
But those cosmic rays can’t reach Earth when the sun is stormy with sunspots and the solar wind is roaring. So a tree ring containing low carbon-14 is a sign of few cosmic rays in that growth year, which is an indicator of a stormy sun, contend Max-Planck-Institut für Sonnensystemforschung’s Sami Solanki and colleagues.
From fig 3 in the reference I give , one sees large variations in C14 ( percentage wise I suppose) so I wonder how well the variation is taken into account in the model you referenced above.
I think the jury should still be out for cosmic rays. Too little is known yet both from that side and from the magnetic activities of the sun, if Livingston and Penn are right, for example.
Leif Svalgaard (23:20:01)
————————-
[snip] ~ charles the moderator
Gary Strand (14:48:17) :
Allan M R MacRae (13:38:13) :
“So when MacRae (#321) says: “I suspect that both the climate computer models and the input assumptions are not only inadequate, but in some cases key data is completely fabricated – for example, the alleged aerosol data that forces models to show cooling from ~1940 to ~1975. Isn’t it true that there was little or no quality aerosol data collected during 1940-1975, and the modelers simply invented data to force their models to history-match; then they claimed that their models actually reproduced past climate change quite well; and then they claimed they could therefore understand climate systems well enough to confidently predict future catastrophic warming?”, he is close to the truth.”
Would you provide proof of your “the modelers simply invented data” claim? For example, show that the sulfate aerosol forcing data that the IPCC AR4 models used was “invented”, by whom, and how.
Extraordinary claims demand extraordinary evidence; please provide some.
____________________________
Some has already been provided Gary, in my above post:
The pyrheliometric ratioing technique is very insensitive to any changes in calibration of the instruments and very sensitive to aerosol changes.
Here are three papers using the technique:
Hoyt, D. V. and C. Frohlich, 1983. Atmospheric transmission at Davos, Switzerland, 1909-1979. Climatic Change, 5, 61-72.
Hoyt, D. V., C. P. Turner, and R. D. Evans, 1980. Trends in atmospheric transmission at three locations in the United States from 1940 to 1977. Mon. Wea. Rev., 108, 1430-1439.
Hoyt, D. V., 1979. Pyrheliometric and circumsolar sky radiation measurements by the Smithsonian Astrophysical Observatory from 1923 to 1954. Tellus, 31, 217-229.
In none of these studies were any long-term trends found in aerosols, although volcanic events show up quite clearly. There are other studies from Belgium, Ireland, and Hawaii that reach the same conclusions. It is significant that Davos shows no trend whereas the IPCC models show it in the area where the greatest changes in aerosols were occurring.
There are earlier aerosol studies by Hand and in other in Monthly Weather Review going back to the 1880s and these studies also show no trends.
___________________________
Repeating: “In none of these studies were any long-term trends found in aerosols, although volcanic events show up quite clearly.”
Doug Hoyt is an authority on these early measurements. I welcome his further comments, and have emailed him of my earlier post on this thread.
Whilst remaining generally supportive of Svensmark’s ideas I remain unconvinced for various reasons:
(i) There are plenty of particulates in the air already.
(ii) The variation in GCRs does not match the timing of temperature changes very well.
(iii) The oceans are a far bigger influence if, as I observe, they change the rate of energy emission to the air for decades at a time.
The observed changes in solar energy reaching the surface would fit well with cloudiness changes induced by ocean SST changes.
1) Warming SSTs first warm the air and initially reduce cloudiness for a while until evaporation catches up. Once evaporation catches up the enhanced water vapour content leads to increased cloudiness and precipitation as the extra energy and vapour is transported to upper levels where condensation occurs. Greater global albedo and less solar energy reaching the surface.
2) Cooling SSTs first cool the air which lies above it resulting in more low level cloudiness for a while but over time the rate of evaporation declines and there is less water vapour content in the air overall and reduced cloudiness and precipitation. Reduced global albedo and more solar energy reaching the surface.
Note that in both cases the response of the hydrological cycle is opposite to the change in ocean SSTs and works to cancel it.
In the case of warming SSTs the air circulation systems move poleward and equatorward for cooling.
The same process cancels the effects of changing GHGs in the air whether they be CO2, water vapour or anything else.
Note that a graph such as the one for Stockholm is not useful due to it being for a single specific location. For a specific location the changes in the amount of energy reaching the surface would be most greatly influenced by the position of that location in relation to the air circulation systems.
For example, in the case of Stockholm it could show more energy reaching the surface in both warming spells (when the mid latitude jets moved to the north) and cooling spells (when the mid latitude jets moved to the south).
The graph seems to confirm that by indicating increased or increasing energy reaching the surface both during the cooling spell of the 50s and 60s and the warming spell of the 80s and 90s.
Diurnal ranges in specific locations would again be primarily affected by that location’s specific position in relation to the movement of the air circulation systems.
Gary Strand (14:48:17) :
Gary, I have read your posts on the earlier “polar bear scientist banned” thread.
I conclude that your comments constitute ignorant baiting, and will have nothing more to do with you. You are a waste of time.
Also, I refuse to duel with an unarmed man.
The thing about artificial dimming to me, is it would seem to have the potential to screw up your trend lines by creating artificial appearance of acceleration of warming over shorter period of times when you clean up the pollution. So that, say, 10 years of warming trend is actually more like 50 years of warming trend that you’ve only been able to detect over the last 10 years. Obviously getting that right makes a big difference in determining what the next 50 years looks like.
Otoh, there’s China to worry about and how much masking they still have going on there.
Stephen Wilde (04:27:02) :
Whilst remaining generally supportive of Svensmark’s ideas I remain unconvinced for various reasons:
(i) There are plenty of particulates in the air already.
(ii) The variation in GCRs does not match the timing of temperature changes very well.
(iii) The oceans are a far bigger influence if, as I observe, they change the rate of energy emission to the air for decades at a time.
Let us not make once more the mistake of thinking linearly of a chaotic system.
It should be evident that climate is a concert, not a solo input “X” output “temperature”. It is a synergy of a lot of factors entering the equations non linearly.
That is the reason I have been asking repeatedly if the “folk science wisdom” that the tree ring widths are modulated by the sun cycles still holds, and asking for a refuting link.
If it still holds, it is an integration of all factors entering climate in real data , and the question should no longer be if the sun cycles affect climate, but how they do it. I keep finding by googling references that it still holds true, there is a modulation of the sun cycles detectable in tree ring widths, but I would really like to see a review link, for , or against.
anna v (00:39:48) :
Too tempting a dictum : I will repeat about tree rings. Science wisdom has it that the 11 year sun cycle was discovered in the change of the width of tree rings in cycles.
This may be a case of bad translation. The solar cycle was ‘discovered’ by looking at the Sun not at tree rings. You may mean that the cycle can also be seen [‘discovered’] in tree rings.
If this is not a “science myth” it means that the climate changes with the cycles enough to be registered by the trees.
Are you aware of a publication that refutes this, or is the scarcity of publication in the google search a proof of your dictum “something is true so no need to establish it”?
Perhaps also simply a reflection of the lack of evidence in the first place.
Secondly, on the subject of cosmic rays, there is a publication that connects C14 with solar cycles
This is well established and there is no doubt about the basics [although there are questions about how much the climate itself influences the deposition process]
I think the jury should still be out for cosmic rays. Too little is known yet both from that side and from the magnetic activities of the sun, if Livingston and Penn are right, for example.
My problem is not with the jury being still out, but with the people who claim that it is not.
dennis ward (22:45:42) :
So because solar radiation has been decreasing since about 1945, does this discredit the theory that the sun has had anything to do with earth’s global warming for the last 65 years?
Hi Dennis. Although sunspot maximum amplitudes declined after the 1960 record breaker, they were still pretty high by historical standards. Although you are correct that the maximum amplitudes diminished as temperature rose, and a superficial analysis might conclude that therefore solar activity doesn’t correlate with temperature, a deeper look at the data reveals something else.
The run of high but diminishing amplitude cycles in the late C20th were shorter than average, with less lengthy low counts at minimum. If you plot a cumulative total of the difference between the monthly sunspot count or total sunspot area and the long term average for the monthly sunspot count, you’ll get a graph which looks like this:
http://s630.photobucket.com/albums/uu21/stroller-2009/?action=view¤t=sst-nino-ssa.jpg
Although my work is preliminary at this point, and Dr Svalgaard has not been encouraging, I think it may shed some light on the solar-climate link, when it is considered that the oceans store heat in the Pacific warm pool in ways which are not measured by SST series. To me, accumulation of heat energy in the PWP means it is reasonable to look at sunspot counts in a cumulative way. When the effects of positive and negative phases of ENSO are subtracted from the equation, the residual looks to me like a reasonably good correlation.
“anna.v
Let us not make once more the mistake of thinking linearly of a chaotic system”.
Let us not make the mistake of assuming that a chaotic system cannot be underlain by a linear change over time. When all is said and done the sun is the sole source of energy for the Earth and it’s energy output varies in a linear fashion.
Tree rings would be affected by solar changes but only indirectly via temperature and precipitation changes. Many other parameters would add to the difficulty of seeking a reliable link between tree rings and solar changes.
Overall the tree ring/solar relationship would be too varaible for diagnostic purposes.
It is for that reason that I think too much reliance has been placed on the bristle cone pine for the purposes of climate speculation.
And what Leif says.
anna v (07:07:53) :
That is the reason I have been asking repeatedly if the “folk science wisdom” that the tree ring widths are modulated by the sun cycles still holds, and asking for a refuting link.
http://www.treeringsociety.org/TRBTRR/TRBvol32_19-33.pdf
“The results show no evidence of significant, consistent relationships between tree-ring data and sunspot numbers”
Tree-ring data are NOT the 14C contents, but the width and appearance of the rings.
A comprehensive bibliography of tree-ring research can be found here: http://www.treeringsociety.org/TRBTRR/TRBTRR.htm
These people are enthusiasts so will leave no stone unturned.
The Sun is downing its emissions of energy, but at a very low extent:
5320 BP: 1367.84 W/m^2
Today: 1365.92 W/m^2
% of dimming = 0.15
The next graph shows the Sun is not the same “giant” than it was 11000 years ago:
http://www.biocab.org/Extrapolated_TSI.jpg
The margins of error on the extrapolation (from HSG proxy) are -0.3 W/m^2, 0.3 W/m^2
Leif Svalgaard (08:47:55) :
Thanks for the links.
I have one recent with positive results: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VHB-4NDDM72-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=942050960&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=d6327d573e47213f5d4ad7451d25ecb6
We have investigated the solar activity signal in tree ring data from two locations in Chile. The tree ring time series extended over a period of not, vert, similar400 yr. Spectral and wavelet analysis techniques were employed. We have found evidence for the presence of the solar activity Schwabe (not, vert, similar11 yr), Hale (not, vert, similar22 yr), fourth-harmonic of the 208-yr Suess cycle (not, vert, similar52 yr) and Gleissberg (not, vert, similar80 yr) cycles. The Gleissberg cycle of tree ring data is in anti-phase with solar activity. Wavelet and cross-wavelet techniques revealed that the periods found are intermittent, possibly because solar activity signals observed in tree rings are mostly due to solar influence on local climate (rainfall, temperature, and cloud cover) where trees grow up. Further, cross-wavelet analysis between sunspot and tree ring time series showed that the cross power around the 11 yr solar cycle is more significant during periods of high solar activity (grand maximum) than during periods of low solar activity (grand minimum). As Glaciar Pio XI is practically at the Pacific Ocean level, the tree-ring response may be stronger due to the heating of the Pacific Ocean water following an increase of the solar radiation incidence rather than at the higher altitudes of Osorno region.
it is behind a pay barrier.
Tree-ring data are NOT the 14C contents, but the width and appearance of the rings.
Yes, of course. I was using the reference for the level of cosmic rays and the correlation with sun cycles with cosmic rays. That was a second point.
anna v (09:57:51) :
I have one recent with positive results:
“Wavelet and cross-wavelet techniques revealed that the periods found are intermittent,”
They find all kinds of periods on and off. Not very positive to me. But it is a myth that is hard to kill.
The tree-ring society http://www.treeringsociety.org/TRBTRR/TRBTRR.htm
has in their extensive bibliography only that one paper with the words sunspot, sun, or solar in the title. I’ll tend to go with the professionals here.
BTW, one of the authors [Echer] of the paper you quoted is a good friend of mine with a propensity for trying to find wavelet cycles everywhere, e.g. here http://www.leif.org/research/Asymmetric%20Rosenberg-Coleman%20Effect.pdf
Sometimes he is a bit too enthusiastic.
Allan M R MacRae (03:23:07)
FABRICATION OF AEROSOL DATA USED FOR CLIMATE MODELS:
The pyrheliometric ratioing technique is very insensitive to any changes in calibration of the instruments and very sensitive to aerosol changes.
Here are three papers using the technique:
Hoyt, D. V. and C. Frohlich, 1983. Atmospheric transmission at Davos, Switzerland, 1909-1979. Climatic Change, 5, 61-72.
Hoyt, D. V., C. P. Turner, and R. D. Evans, 1980. Trends in atmospheric transmission at three locations in the United States from 1940 to 1977. Mon. Wea. Rev., 108, 1430-1439.
Hoyt, D. V., 1979. Pyrheliometric and circumsolar sky radiation measurements by the Smithsonian Astrophysical Observatory from 1923 to 1954. Tellus, 31, 217-229.
In none of these studies were any long-term trends found in aerosols, although volcanic events show up quite clearly. There are other studies from Belgium, Ireland, and Hawaii that reach the same conclusions. It is significant that Davos shows no trend whereas the IPCC models show it in the area where the greatest changes in aerosols were occurring.
There are earlier aerosol studies by Hand and in other in Monthly Weather Review going back to the 1880s and these studies also show no trends.
___________________________
Repeating: “In none of these studies were any long-term trends found in aerosols, although volcanic events show up quite clearly.”
___________________________
Here is an email just received from Douglas Hoyt [my comments in square brackets]:
It [aerosol numbers used in climate models] comes from the modelling work of Charlson where total aerosol optical depth is modeled as being proportional to industrial activity.
[For example, the 1992 paper in Science by Charlson, Hansen et al]
http://www.sciencemag.org/cgi/content/abstract/255/5043/423
or [the 2000 letter report to James Baker from Hansen and Ramaswamy]
http://74.125.95.132/search?q=cache:DjVCJ3s0PeYJ:www-nacip.ucsd.edu/Ltr-Baker.pdf+%22aerosol+optical+depth%22+time+dependence&cd=4&hl=en&ct=clnk&gl=us
where it says [para 2 of covering letter] “aerosols are not measured with an accuracy that allows determination of even the sign of annual or decadal trends of aerosol climate forcing.”
Let’s turn the question on its head and ask to see the raw measurements of atmospheric transmission that support Charlson.
Hint: There aren’t any, as the statement from the workshop above confirms.
__________________________
IN SUMMARY
There are actual measurements by Hoyt and others that show NO trends in atmospheric aerosols, but volcanic events are clearly evident.
So Charlson, Hansen et al ignored these inconvenient aerosol measurements and “cooked up” (fabricated) aerosol data that forced their climate models to better conform to the global cooling that was observed pre~1975.
Voila! Their models could hindcast (model the past) better using this fabricated aerosol data, and therefore must predict the future with accuracy.
That is the evidence of fabrication of the aerosol data used in climate models that predict catastrophic humanmade global warming.
And we are going to spend trillions and cripple our Western economies based on this fabrication of false data, this model cooking, this nonsense?
*************************************************
Allan M R MacRae (10:41:55) :
There are actual measurements by Hoyt and others that show NO trends in atmospheric aerosols, but volcanic events are clearly evident.
So, you are saying that since there is no trend in aerosols, the climate changes must be anthropogenic. A lot of people, even scientists [didn’t I see somewhere that 30,000 of those critters supports the IPCC’s assessments…] would agree with that, voting for this government.
Once the Western economies are crippled and the bulk of industrial output is shifted to the East, the world will be saved from the austerity of the skies clearing and global warming frying the planet. Asia will never stop burning coal until there isn’t any more to burn.
They call it saving the planet from impending disaster.
I call it capitulation.
As capital, output and might shift to the non-free world, the balance of power will be upset, and the inevitable consequences of the weakening of the Free World will be felt.
All because of fabricated models.
Just have a look at the video of Global Dimming. What you do hear is the increase of daytime temps. What I do not hear is what happened to the nighttime temps as a result of a clearing atmosphere.
Did the diurnal range simply widen at both ends, or on one end?
The assumed ‘brightening’ at Stockholm in recent years does not agree with other global dimming reports.
http://en.wikipedia.org/wiki/Global_dimming
Leif Svalgaard (11:31:22) :
Allan M R MacRae (10:41:55) :
There are actual measurements by Hoyt and others that show NO trends in atmospheric aerosols, but volcanic events are clearly evident.
So, you are saying that since there is no trend in aerosols, the climate changes must be anthropogenic. A lot of people, even scientists [didn’t I see somewhere that 30,000 of those critters supports the IPCC’s assessments…] would agree with that, voting for this government.
——————–
No Leif, as you know, I’m not saying that.
There are many other causative variables for climate, such as clouds, oceans, volcanoes, etc.
But increased atmospheric CO2 is NOT a significant driver of global warming – that much is obvious by now.
The sensitivity of global temperature to increased atmospheric CO2 is so small as to be inconsequential – much less than 1 degree C for a doubling of atmospheric CO2. CO2 feedbacks are negative, not positive. Climate model hindcasting fails unless false aerosol data is used to “cook” the model.
Regards, Allan
P.S. I’m sorry about the death of your friend Jack Eddy.
_____________________________
Here is a reasonable summary for anyone who is interested:
http://scienceandpublicpolicy.org/a_proper_focus_in_the_climate_change_debate.html
A Proper Focus in the Climate Change Debate
The Debate Is Not Over. Early in 2007 there was a concerted, international effort among climate alarmists to suggest that the science was so certain that debate was no longer possible. That effort had no impact on the scientific community, which continues to debate climate change vigorously and sometimes even acrimoniously in the peer-reviewed, learned journals. The debate continues.
Climate change has always been real, but the fact of climatic variability tells us nothing of its cause. The more the climate is researched, the less likely it appears that humankind has had any significant climatic impact.
Climate change is not unprecedented. The mediaeval warm period was warmer than the present. Even now, melting glaciers in the Alps are revealing mediaeval trackways, silver-mines and even entire forests that have been buried under ice since the Middle Ages. Some of the Viking settlements in Greenland are still under permafrost to this day.
The chicken and the egg: The temperature changes that led to the ice ages and interglacial period preceded changes in CO2 concentration.
The central calculation: The UN says a doubling of CO2 concentration will push global temperatures up by 3C. Others say less than 1C.
Will warming be harmful? Almost certainly not. Warming is better than cooling. We now know that neither droughts nor floods nor storms have increased or are likely to increase as a result of anthropogenic warming; these events come and go in natural cycles which have scarcely altered over the past 100 years.
What is the cause of the present warming? Even if one assumes that the UN’s estimates of recent warming are not themselves an exaggeration, observations do not confirm the presence, in any climatically-significant degree, of the characteristic signature of anthropogenic warming – namely, a greater rate of increase in temperature at altitude, particularly at low latitudes, than at the surface. These results provide proof that much of the present warming is not anthropogenic but natural, caused partly by millennial alterations in patterns of ocean circulation and partly by the Sun, which has been more active, and for longer, in the past 70 years than at almost any time in at least the past 11,400 years (Solanki et al., 2005).
Will proposed mitigative measures cost more than they achieve? Now that the predictions of the extremists have been discredited even by the UN, it is near-certain that the cost of almost any measure to mitigate the volume of anthropogenic CO2 emissions will outweigh the effectiveness and economic benefit of that measure. Most proposed measures would not make any significant climatic difference even if implemented. The few measures that might have some impact would have only a small impact, but will prove impossible both politically and economically, and will not be achieved, though much money will be wasted in the attempt. It is the poorer nations who will suffer most grievously by the proposed restrictions on CO2 emissions.
What is the real problem? Energy is the real problem. Primary energy sources, particularly fossil fuels, are becoming scarce and expensive, and are increasingly in the hands of unstable regimes that are unfriendly to the West. Energy prices are already rising, but could rise very much more quickly in the coming years.
*****************************
Allan M R MacRae (12:54:27) :
“There are actual measurements by Hoyt and others that show NO trends in atmospheric aerosols, but volcanic events are clearly evident.”
But increased atmospheric CO2 is NOT a significant driver of global warming – that much is obvious by now.
But what has that to do with aerosols?
No Leif, as you know, I’m not saying that.
You may not have meant it that way, but you were saying that.
partly by the Sun, which has been more active, and for longer, in the past 70 years than at almost any time in at least the past 11,400 years (Solanki et al., 2005).
There is no good evidence for that. Solanki’s ‘result’ is partly based on a now [generally accepted] refuted doubling of the Sun’s open magnetic flux, and partly on wrongly calibrated group sunspot number.
Another example of bias [anything goes to defeat that damn AGW, even dubious ‘results’ as long as it works, a la Carlin].
Leif Svalgaard (13:21:18) :
There is no good evidence for that. Solanki’s ‘result’ is partly based on a now [generally accepted] refuted doubling
It is the refutation that is generally accepted by now, even by Lockwood and by me [we were the ones culpable of advocating that notion in the past].
“A two-year study of San Joaquin Valley nights found that summer nighttime low temperatures in six counties of California’s Central Valley climbed about 5.5 degrees Fahrenheit (approximately 3.0 C) between 1910 and 2003.”
I believe there will be correlation with the amount of irrigation going on. The Central Valley is probably much more humid in 2003 at dawn that it was in 1910 due to more overnight irrigation. More humidity means less radiation into space and more warming of the lower layers of air.
Sort of like the difference in temperature between Winnamucca and Miami at 5am on a May morning.
Leif Svalgaard (13:21:18) :
Allan M R MacRae (12:54:27) :
“There are actual measurements by Hoyt and others that show NO trends in atmospheric aerosols, but volcanic events are clearly evident.”
But increased atmospheric CO2 is NOT a significant driver of global warming – that much is obvious by now.
Leif: But what has that to do with aerosols?
**************************
Leif, I did say:
The sensitivity of global temperature to increased atmospheric CO2 is so small as to be inconsequential – much less than 1 degree C for a doubling of atmospheric CO2. CO2 feedbacks are negative, not positive. Climate model hindcasting fails unless false aerosol data is used to “cook” the model.
Connecting the dots, to answer your question:
The fabricated aerosol data allows climate model hindcasting to appear credible while assuming a false high sensitivity of global temperature to atmospheric CO2.
The false high sensitivity is then used to forecast catastrophic humanmade global warming (the results of the “cooked” climate models).
What happens if the fabricated (phony) aerosol data is not used?
No phony aerosol data > no credible model hindcasting > no artificially high climate sensitivity to CO2 > no model forecasting of catastrophic humanmade global warming.
Regards, Allan
Supporting P.S.:
Earth is cooling, not warming. Pass it on…
Leif Svalgaard (13:21:18) :
There is no good evidence for that. Solanki’s ‘result’ is partly based on a now [generally accepted] refuted doubling
It is the refutation that is generally accepted by now, even by Lockwood and by me [we were the ones culpable of advocating that notion in the past].
**************************
I can’t argue with you on this point. I am much more conversant on the other eight points in the SPPI document, and generally find them acceptable.
Willie Soon is the Chief Science Advisor of SPPI
http://scienceandpublicpolicy.org/personnel.html
Presume you know Willie since you are in a similar line of work – you may want to take this up with him.
BTW, some time ago I sent you a paper by Jan Veizer (GAC 2005) that in Figure 2 showed an apparently strong correlation between Cosmic Ray Flux and Low Cloud cover, (after Marsh and Svensmark 2003 and Marsh et al 2005). Did you get this paper? Do you accept or reject this correlation?
Regards, Allan
Allan M R MacRae (16:39:22) :
The fabricated aerosol data allows climate model
As I read Wild’s paper, I don’t see any fabricated aerosol data, unless you invoke a global conspiracy going back almost a century. It that the message?
Allan M R MacRae (16:39:22) :
Supporting P.S.:
Earth is cooling, not warming.
Supporting P.P.S.:
Human-made CO2 emissions have increased almost 800% since 1940, but the best data shows no significant net warming since ~1940. This lack of significant warming is evident in UAH Lower Troposphere temperature data from ~1980 to end April 2008, and Hadcrut3 Surface Temperature data from ~1940 to ~1980.
See the first graph at:
http://www.iberica2000.org/Es/Articulo.asp?Id=3774
Climate sensitivity to increased atmospheric CO2 and humanmade CO2 emissions is insignificant.
Figure 2 shows a huge change in annual mean surface solar radiation. It’s about 95 watts/sq meter in the early 20’s to 135 in the early 40’s. If that data is correct it must be highly localized. If that kind of a change occurred over a large portion of the earth it would cause a very large jump in temperature, far more than the .7 C the IPCC claims.
Allan M R MacRae (16:58:30) :
BTW, some time ago I sent you a paper by Jan Veizer (GAC 2005) that in Figure 2 showed an apparently strong correlation between Cosmic Ray Flux and Low Cloud cover, (after Marsh and Svensmark 2003 and Marsh et al 2005). Did you get this paper? Do you accept or reject this correlation?
It doesn’t look too good, and employs a standard technique of persuasion, namely plotting some other quantities as well that are well correlated to ‘guide’ the eye. Svensmark notes that perhaps a better calibration of the spacecraft data would improve the correlation. The recent albedo data of Palle also do not support the correlation, as there is no clear solar signal.
Leif Svalgaard (17:03:08) :
Allan M R MacRae (16:39:22) :
The fabricated aerosol data allows climate model
As I read Wild’s paper, I don’t see any fabricated aerosol data, unless you invoke a global conspiracy going back almost a century. It that the message?
__________________
Leif, thanks for clearing this up with your question.
I am not addressing Wild’s model – I am addressing the 1992 paper in Science by Charlson, Hansen et al, that has been used as a basis for so many climate models that falsely predict catastrophic global warming.
The Charlson et al paper fabricates aerosol data based on industrial activity, when actual measurements were available that refute Charson’s conclusions.
I have no opinion on Wild’s paper. Normally I read a paper several times, check the raw data and calculations, read many related papers, and then form an opinion. As you can appreciate, this takes some time.
Allan M R MacRae (20:03:32) :
I am not addressing Wild’s model
Which is the topic of this thread.
Isn’ t this review a proxy for albedo?
Leif,
do you have an ‘adjusted’ sunspot number series file I can test my cumulative method on? Is the sunspot area series available from NASA still valid in your view?
Leif Svalgaard (13:21:18) :
“There is no good evidence for that. Solanki’s ‘result’ is partly based on a now [generally accepted] refuted doubling of the Sun’s open magnetic flux, and partly on wrongly calibrated group sunspot number.”
You may like to comment on this paper as you are heavily cited.
On the long term change in the geomagnetic activity during the 20th century
F. Ouattara1, C. Amory-Mazaudier2, M. Menvielle3,4, P. Simon*,†, and J.-P. Legrand*
Abstract. The analysis of the aa index series presented in this paper clearly shows that during the last century (1900 to 2000) the number of quiet days (Aa<20 nT) drastically diminished from a mean annual value greater than 270 days per year at the end of the nineteenth century to a mean value of 160 quiet days per year one hundred years later. This decrease is mainly due to the decrease of the number of very quiet days (Aa<13 nT). We show that the so-evidenced decrease in the number of quiet days cannot be accounted for by drift in the aa baseline resulting in a systematic underestimation of aa during the first quarter of the century: a 2–3 nT overestimation in the aa increase during the 20th century would lead to a 20–40% overestimation in the decrease of the number of quiet days during the same period.
The quiet days and very quiet days correspond to periods during which the Earth encounters slow solar wind streams flowing in the heliosheet during the period where the solar magnetic field has a dipolar geometry. Therefore, the observed change in the number of quiet days is the signature of a long term evolution of the solar coronal field topology. It may be interpreted in terms of an increase in the magnitude of the solar dipole, the associated decrease of the heliosheet thickness accounting for the observed decrease in the number of quiet days.
http://www.ann-geophys.net/27/2045/2009/angeo-27-2045-2009.html
anna v (22:37:14) :
Isn’ t this review a proxy for albedo?
Close, but not quite. Albedo is seen from the outside, the solar radiance from the inside of the atmosphere.
tallbloke (22:43:11) :
do you have an ‘adjusted’ sunspot number series file I can test my cumulative method on? Is the sunspot area series available from NASA still valid in your view?
The ‘corrected sunspot number’ is still a work in progress. You can find what I have at http://www.leif.org/research/files.htm
Look for:
Corrected SSN and TSI.prn
Corrected SSN and TSI.txt
Corrected SSN and TSI.xls
Corrected Sunspot Series 1841-Present.xls
The sunspot areas between 1874 and 1976 are good. Hathaway has a continuation until the present at http://solarscience.msfc.nasa.gov/greenwch.shtml
There are some issues with splicing together the newer and older data.
maksimovich (22:54:40) :
You may like to comment on this paper as you are heavily cited.:
On the long term change in the geomagnetic activity during the 20th century
F. Ouattara1, C. Amory-Mazaudier2, M. Menvielle3,4, P. Simon*,†, and J.-P. Legrand*
This is a poor paper, and their interpretation of their ‘result’ is a rehash of thirty-year old ideas of Simon and Legrand [which I do not subscribe to]. The story about aa has two aspects:
1) an error in calibration before 1957
2) inhomogeneity in the index caused by Mayaud providing all values before 1937, but using existing scalings afterwards.
(1) is addressed in section 5.3 of http://www.leif.org/research/2007JA012437.pdf
and (2) is touched upon here:
http://www.leif.org/research/Analysis%20of%20K=0%20and%201%20for%20aa%20and%20NGK.pdf
Leif Svalgaard (21:30:47) “[…] i.e. not the climate models that pretend to forecast a hundred years ahead the effect of a butterfly beating its wings.”
priceless
Re: tallbloke (08:35:17)
Something you might want to try sometime when you do your integrations: Use variable-bandwidth. (Excel is friendly to this sort of calculation if you are adept at using the “offset” function. If you run into problems with ragged vector-lengths as bandwidth varies (which results in triangular arrays), use the “count” & “counta” functions [in concert] to guide Excel around missing/error values.
Leif Svalgaard (23:20:46) “[…]
1) an error in calibration before 1957
2) inhomogeneity in the index caused by Mayaud providing all values before 1937, but using existing scalings afterwards.”
Aside:
I hope you will write an authoritative (but concise) overview of the aa index & its history one day (for a non-specialist general-science audience).
– –
Question for anyone who can answer:
Recently I estimated the historical Chandler wobble period using wavelet methods. I contrasted the curve I got with a precipitation curve. When studying the residuals I noticed a *consistent phase agreement with aa index up until (but not beyond) the 1930s – so the first question that popped into my mind was about instruments & measurement methods – and since I know little of instruments & measurements I have to ask:
Is there anything [obvious] that would affect
BOTH
a) aa index measurements
AND
b) precipitation measurements &/OR polar motion measurements
BEFORE the 1930s
but NOT afterward?
To WUWT: Thank you for running a story paying attention to DTR (which is on the radar of the “top” climate modelers).
General Note:
When considering DTR, it is important to differentiate between coastal & continental sites.
anna v, I had a look at the tree-ring paper you mentioned. After looking at the wavelet plots and reading the accompanying text: I’d want to run my own analyses (if I had access to the tree-ring data) and ask the authors some questions before drawing conclusions. Note: I am thankful that a liberal publication system allows us to see what others are doing.
Paul Vaughan (01:08:50) :
Is there anything [obvious] that would affect
BOTH a) aa index measurements
AND b) precipitation measurements &/OR polar motion measurements
No
Paul Vaughan (01:08:50) :
I hope you will write an authoritative (but concise) overview of the aa index & its history one day (for a non-specialist general-science audience).
This may not be possible as the issues are complex.
I’m giving an invited talk on this at the IAGA 2009 conference http://www.iaga2009sopron.hu/ in August:
H02. History of geomagnetic observations, observatories, & indices
This session of invited talks will trace the history of the study of earth’s magnetism including: Gilbert’s De Magnete, early studies of geomagnetic activity by Graham and Celsius, Gauss and Weber’s Magnetic Union, Sabine’s British Colonial Observatories, establishment of the solar-terrestrial connection, Bartels’ development of geomagnetic indices, and the modern Intermagnet and space borne observation programs.
—–
Perhaps my write-up of the talk might serve.
P.S. You still have not told me her ‘central thesis’ was.
Please do.
Paul Vaughan (01:08:50) :
Leif Svalgaard (06:47:49) :
“I’m giving an invited talk on this at the IAGA 2009 conference http://www.iaga2009sopron.hu/ in August:”
I forgot to include the abstract:
Geomagnetic variation is an extremely complicated phenomenon with multiple causes operating on many time scales. 250 years ago, Hjorter noticed its ‘regular irregularity, and irregular regularity’. The immense complexity of geomagnetic variations becomes tractable by the introduction of suitable geomagnetic indices on a variety of time scales, some specifically targeting particular mechanisms and physical causes. We review the historical evolution of the ‘art of devising indices’. Different indices [by design] respond to different combinations of solar wind and solar activity parameters and in Bartels’ [1932] words “yield supplemental independent information about solar conditions” and , in fact, have allowed us to derive quantitative determination of solar wind parameters over the past 170 years. Geomagnetic indices are even more important today as they are used as input to forecasting of space weather and terrestrial responses.
Is it from Gauss that we get our term de-gauss, a step in computer screen maintenance to right a skewed monitor view? I had a problem with that once when I placed a tower speaker next to the screen and the view appeared to be magnetically attracted to the speaker. When I looked into it, the problem was a magnetic one? Or was it related to static electricity? These two sometimes confuse me as static electricity sometimes appears magnetic as in the balloon on hair trick.
Leif and Paul,
Thank you both for your input. FWIW the cumulative running totals I get for sunspot numbers and sunspot areas agree very closely, except for very recent data where the large number of ‘tiny tims’ of negligible area upsets the correlation.
Pamela Gray (07:44:49) :
Is it from Gauss that we get our term de-gauss, a step in computer screen maintenance to right a skewed monitor view?
Yes.
I had a problem with that once when I placed a tower speaker next to the screen and the view appeared to be magnetically attracted to the speaker. When I looked into it, the problem was a magnetic one?
Magnetic. You can distort the TV image [if you still have a tube] with a powerful magnetic held [or better yet, moved around] next to the tube.
Leif, I was wondering about your thoughts of my two criticisms of the article.
One, I wonder if trade wind and jet stream patterns can be linked to the presence or absence of aerosols over time. The presence of aerosols at any one place cannot be assumed to be its source. They were probably driven there.
And two, natural dust is a powerful aerosol. It kicks up here in the northeast corner of Oregon. A case in point, palouse soil is soil brought by the wind. We have plenty of it here but it came from somewhere else. Palouse soil is easily kicked up into the wind. We have had cloudless rain on many occasions. When farmers lay a circle of soil to rest instead of plant and water it, the soil takes to the wind. We don’t grow nearly the acres of wheat we used to grow since crop land was put into conservation programs. But this dry shrubby desert soil then gets kicked up by the wind during high wind seasons because there is little cover crop land to anchor it. In the old days, before high plains soil was planted, dust storms were as bad as ever. Then when Columbia River water was used to drive circle irrigation systems, that soil was anchored. We are now beginning to experience dust storms again because the high plains are not as intensively farmed. I think natural dust, like you get off of the deserts of Africa, is a very significant source of aerosols and may overwhelm what the authors seem to infer as major anthropogenic sources. His conclusions seem to place more emphasis one anthropogenic sources than the study merits.
Pamela Gray (07:44:49) :
Is it from Gauss that we get our term de-gauss, a step in computer screen maintenance to right a skewed monitor view? I had a problem with that once when I placed a tower speaker next to the screen and the view appeared to be magnetically attracted to the speaker.
It is magnetic fields that distort screens.
When working with a CERN experiment that had a field in the center of 15000 Gauss all the screen displays were skewed by the firnge fields and we had to turn our heads around to read them. I felt my head ringing too :).
Pamela Gray (08:21:58) :
His conclusions seem to place more emphasis one anthropogenic sources than the study merits.
I really don’t have any opinion on this [don’t know enough] but what caught my interest were the actual measurements of the solar radiance over ~ a century and how much it varied [from whatever source]. When we lived in Belgium we regularly has windblown dust from Sahara, so aerosols and dust travel far.
Pamela Gray (08:21:58) :
Anthropogenic means created by man. Are you sure that
. We don’t grow nearly the acres of wheat we used to grow since crop land was put into conservation programs. But this dry shrubby desert soil then gets kicked up by the wind during high wind seasons because there is little cover crop land to anchor it. In the old days, before high plains soil was planted, dust storms were as bad as ever.
the reason there is little cover is not due to man set fires at some point or other?
Even for the Sahara I have read studies that well digging and goats are advancing the desert in leaps and bounds because herders increase their goat herd once there is a well and the goats eat everything till the area dries up.
We get a lot of red rain, mud from the Sahara, in Greece.
In Oregon, we are not growing the tonnage we used to. We are getting more dust in the air as a result. The natural condition of the high desert plains is one of dusty dry palouse soil as well as fine sand. This, combined with high winds, becomes a natural aerosol ladened atmosphere. Close by, much of the soil now used for vineyards (and high-placed mansions) in around Pullman, WA was blown there long before tilled and irrigated agriculture became wide spread. So too the high desert plains of Oregon. However, efforts were made to reduce this dust in the air by planting and irrigating with that purpose in mind. But then it was decided that natural landscapes and soil left to itself is better. When land is placed in conservation programs, the emphasis is low or no tilling, natural cover crops, or none at all, and no irrigation. And so the dust is beginning to rise again. The point is that dust in the atmosphere is likely a natural decadel phenomena combined with agricultural practice that reduces it here and there, and/or now and then. As a pollution source, you will need to tease out natural phenomena from human sources.
I meant to say human sources from natural phenomena. This means that some satellite will have to be able to determine polluted dirt in the air from natural dirt in the air. I would hazard a guess that most aerosols are natural occurring phenomena (here again, the null hypothesis). It will be a neat trick to determine otherwise.
Anna, it is just the opposite. Man-made fire suppression has greatly endangered the forests and cause erosion prone soil. Without the regular vacuum of natural fires that are allowed to burn where they will, floor fuels build up everywhere and cause extremely hot wide-spread blanket fires that burn from below the ground to the tops of the trees. Natural fires follow a snake like path through the forest and only burn what little fuel there is at ground level. They don’t even sanitize the soil. Catastrophic fires of the kind only seen with large ground level fuel loads, sanitize the soil of seeds that could have otherwise sprouted after natural fires.
IMHO, to get back to healthy forests, all US national forests should be returned to the states and put under local control with the following conditions: fires should be allowed to burn and grazing should once again be the standard practice. Those that build houses in the forest are on their own and should carry rather large expensive insurance on their holdings. If this were to happen, forest management would not produce any added atmospheric or erosion problems.
Pamela Gray (08:21:58)
The issue of natural aerosols has interested me for some time. In fact, ever since the first satellite photos of Earth.
The fact is that even if there were no humans at all the continental areas would still generate huge volumes of atmospheric particulates and smoke from large scale fires caused by lightning strikes.
Putting the blame for much of the particulates in the air on humans is just silly. We reduce natural particulates and increase them in pretty much equal measure by our activities.
I was astonished to read once that a visible brown line seen at the horizon from polar regions was apparently caused by human pollution. In fact it was more likely a natural phenomenon from particulates raised over continental areas quite naturally.
That’s not to say we make no contribution at all. From time to time and on a limited scale I’m sure we have some effect but in my view it is grossly overstated.
There is a tendency for many to regard ANY newly observed phenomenon as a malign consequence of human activity.
It’s a modern extension of the witch doctors and soothsayers of the past.
At base we are far more primitive than is generally accepted.
All I was saying was that probably the pristine state of the land, before man started burning to create grazing land would be covered with grass and bushes, even in desert surroundings, so what is man’s intervention and what is not is very complicated.
Greece was 80% woodland in the 19th century. It is barely 30% now, and it is even worse for western Europe where one travels through thousands of miles of what would have been wooded hills and are now cultivated.
I would agree that it is very complicated to separate man induced from natural.
Yes, lightnings start fires, but usually they are accompanied by strong rains which limit the extent of fires. I live across a pine wood recovered mountain. In my fifty years in this area I have seen only once lightning strike a pine . The rain put the fire out. The probability is low.
It is the fires started by shepherds so that new grass will grow in the winter that have denuded most islands and mountains in Greece, and this has been happening over the last hundred of years or more .
anna v
There are large areas of the continents where lightning is frequently not accompanied by rain reaching the ground.
Lightning strikes without rain have been historically the main cause of large scale conflagrations.
Many forested area in the drier parts of the world have always been subject to regular burns and the local wildlife has adapted accordingly.
If anything human intervention has reduced the scale and frequency of such events so as to protect property.
Greece is mostly a dry area and, before the shepherds, natural fires were just as effective at clearing old undergrowth as anything the shepherds do now. Furthermore the encouragement of winter grass growth tends to fix the soil and reduce the transfer of particulates to the air.
In any event I would have thought the main influence on global dimming and brightening would be cloud cover variations from natural causes rather than anything humans could do.
Re: tallbloke (07:54:31)
Also, once you are proficient with the 2 different ways to use the offset function, it’s a piece of cake to get Excel to consider all possible lags (& hence run cross-correlation analyses). When it comes time for generating summaries, you may find the “match” and “index” functions useful.
I advise modular construction. If you try to create one large glorious workbook that “does everything” in Excel, you’ll end up spending most of your time rebooting your computer; however, if you keep workbooks under 100MB and submit just sheets of values from one book to another – never having more than one module open at a time – it’s clear sailing. It’s sort of like driving a well-engineered standard (manual transmission automobile) if you get the module sizes right …but if you get greedy with your algorithms: it’s crash, crash, crash.
Btw: Doing wavelet analysis in Excel is a breeze once you master the offset function.
My main complaint about Excel [hopefully someone influential at Microsoft is reading]: Color-contour plots do not (!) have a flexible aspect ratio.
You can make nicer color-contour plots in SPlus or R (since the color palette is more flexible), but the programming code is hideous and algorithm-debugging is inefficient since the code is not “live”. [Pouring over hundreds of lines of unaesthetic code looking for a missing comma? – & relying on a dissonant algebraic framework that forces endless transposes? – no thanks if there is an alternative …and no wonder people resort to using other peoples’ wavelet software without understanding it.]
Final Sales-Pitch:
Don’t underestimate what you can do in Excel once you master the offset function.
– –
Pamela, you bring up some interesting points about anthro-land-use influences on decadal-timescale variations.
We need to figure out the conditioning (switch-flipping – masking or enhancement) that drives the various intermittent “wiggle-matches” we see. It’s not necessarily about intermittent causation – it can be a third (lurking) variable influencing 2 study variables, for example.
There’s obsessive linear focus on amplitudes and a vast majority of researchers appear timid about studying phase. Study of phase relations is complex, so established researchers don’t seem keen about risking their reputations on it (“taking one for the team”, so to speak), but we’re just delaying vital progress by submitting to paralyzing cultural norms.
Expertise secures higher regard when “evaporating correlations” are explained rather than dismissed.
– –
Leif, have decisive conclusions been drawn about links (or lack thereof) between Earth Orientation Parameters (EOP) and geomagnetic indices – particularly aa index?
Noteworthy:
Nobel laureate Dr. Andrew Weaver appears to have briefly explored DTR.
http://climate.uvic.ca/people/weaver/
On his “Publications” page, search:
1) “diurnal temperature range” (without the quotes) and
2) “daily maximum and minimum temperature”.
Note the date on the relevant publications (2002 & 2003). Around that time, Dr. Weaver’s home province, British Columbia, Canada – which has a carbon tax – was publishing Tmax & Tmin trends based on LINEAR assumptions – which, if extrapolated into the future, produced Tmin GREATER THAN Tmax (!) – dragging along the average, of course, which is defined as (Tmax+Tmin)/2.
It is interesting to note that BC’s more recent trend-summaries have become less-easily-shot-down. I interpret the substantial changes as acknowledgment of a very serious weakness in earlier model-derived trend-summaries.
Many other jurisdictions have made the same serious mistake of using simple linear regression to summarize (& extrapolate) trends.
Historians: It might be worth archiving some of the (increasingly oldschool) linear trend-summary webpages before more administrators get panicky and issue directives to have them torn down (in haste). It might be informative to note which jurisdictions are the last to abandon the overly simplistic (& formerly conventional) linear-assumption-based summaries.
Paul Vaughan (15:04:03) :
Leif, have decisive conclusions been drawn about links (or lack thereof) between Earth Orientation Parameters (EOP) and geomagnetic indices – particularly aa index?
Nothing is ever ‘decisive’, but my take is that the energy in geomagnetic and solar wind coupling isn’t here to have any effect. Many people have looked at this and none have demonstrated anything significant, but I’m sure you can find links to anything to desire. A fertile ground is looking for semiannual correlations because aa has one [having three or four different causes, the dominant being the size of the magnetosphere controlled by the angle between the solar wind and the Earth’s magnetic axis], but you of course know what the best fertilizer is…
Stephen Wilde (13:39:53) :
I am not disputing that lightnings do set fires, or that there may not be dry lightning. Pine forests reproduce by fire ( the cones burst and bury the seeds in ash fertile ground)
I am saying that in my area, Greece, woodland was 80% in the 1800 hundreds and is 30% or less now. Destructive fires might have happened once in forty years naturally , now they go on every summer because from a lent observing mostly vegetarian diet we have turned to a meat eating society appreciating goat and lamb every week instead of just for Easter and feasts.
I think that people do have great influence in local weather from changes in land use and even a more global one if extensive irrigation or denudation takes place. These change cloud cover ultimately. It is fortunate that 3/4 of the earth is ocean.
Certainly CO2 should be the last on the list.
Re: Leif Svalgaard (18:30:48)
Thank you for this comment.
Strongly recommended reading:
Jan Vondrak (1999). Earth rotation parameters 1899.7-1992.0 after reanalysis within the hipparcos frame. Surveys in Geophysics 20, 169-195.
http://www.yspu.yar.ru/astronomy/lib/Rotation.pdf
[See particularly section 3.2.]
J. Vondrak & C. Ron (2005). The great Chandler wobble change in 1923-1940 re-visited. In: H.-P. Plag, B. Chao, R. Gross, & T. Van Dam (eds.), Forcing of polar motion in the Chandler frequency band: A contribution to understanding interannual climate variations, Cahiers du Centre Europeen de Geodynamique et de Seismologie 24, 39-47.
I am sorry but I must dispute that.
The ancient Greeks used timber for building to such an extent that they ran out of it, and had to turn to stone. To see how elegant their timber buildings must have been visit New England and its classical architecture in the wood: to see how clumsy it’s stone replacement was and is only look about you and see those mighty stone columns.
So abundant was timber that the Roman Empire did not run out of wood in either Hispania or Gaul, see one Julius and the seige of Massila, or indeed young Cicero
The disaster came with the Ottoman empire which introduced goats as a source of milk, flesh and wool. But goats eat everything including young saplings so the forests could not regrow.
To be fair to them, not that I care to, the Spanish government has recognised that pine trees are not natural in the South and that Cervantes had a point when he said that a squirrel could travel from Madrid to Malaga without touching the ground.
And so they are planting new decidious forests, but the project will take a hundred years so I for one shall not see the result. But I wish them well.
The point being that humans can do affect small areas of the world with their urbanisation and agriculture: but what is that given the tiny fraction of the globe they occupy?
Do you really imagine our puny efforts can affect the great natural forces that drive our global climate?
Sorry to be so pedantic.
Kindest Regards
Paul Vaughan (22:04:18) :
Re: Leif Svalgaard (18:30:48)
Thank you for this comment.
Perhaps you would be so kind as to tell me what ‘her central thesis’ was?
Paul Vaughan (22:28:05) :
Jan Vondrak (1999). Earth rotation parameters 1899.7-1992.0 after reanalysis within the hipparcos frame. Surveys in Geophysics 20, 169-195.
When reading papers about this, don’t be confused between tidal components and geomagnetic activity effects. Another frequent point of confusion is the difference between geomagnetic activity [caused by the solar wind] and expansion of the thermosphere [caused by solar irradiance variation in the UV]. The latter clearly having an effect on the LOD because of corresponding changes of the moment of inertia.
a jones (23:18:19) :
I am sorry but I must dispute that.
The ancient Greeks used timber for building to such an extent that they ran out of it, and had to turn to stone.
That Greece came out of the Ottoman rule with 80% forest coverage, and currently has about 30% is not disputable. I cannot discuss woodlands and ancient Greece, except noting that “running out of wood” would need many qualifications as: which part of Greece considering the many city states.n Considering also that the Aegis of Athena was made of goat skin, I doubt that it was the Ottoman who introduced goats to Greece.
Re: Leif Svalgaard (02:56:32)
If I understand what you are saying here:
You are cautioning me not to confuse (small?) radiation tides (~11a period) with geomagnetic effects (since there is statistical confounding of these variables).
–
I addressed your other concern (in a single sentence) some time ago.
I recently learned that the Earth’s distance from the sun varies more than i’d thought. The part I knew about was the eccentricity of the Earth’s orbit (+/-1.7% variation in distance). the other part is the size of the sun’s orbit around the solar system’s center of mass. The Sun’s orbital radius is +/-3% of the earth’s, chiefly because of Saturn’s and Jupiter’s motion. So, the variation in the Earth’s distance from the Sun can be as big as +/-4.7%. This amounts to 18.8% variation in how much light we receive.
Note that this 19% variation is about what the graph shows. Note also that the graph’s curve has a principal wavelength of about 20 years, which closely matches the time it takes for Earth, Jupiter, & Saturn to repeat their arrangements around the Sun. This 20-year period is called the synodic period for Jupiter & Saturn.
Paul Vaughan (19:01:34) :
If I understand what you are saying here:
You are cautioning me not to confuse (small?) radiation tides (~11a period) with geomagnetic effects (since there is statistical confounding of these variables).
That is one reason.
I addressed your other concern (in a single sentence) some time ago.Not to my satisfaction, would I otherwise continue to ask? I maintain that I have no idea what her central thesis is and that her papers must be judged on their merit, not on someone’s perceived thesis. So, one more time: please tell me what you think her central thesis is and how I have failed to take that into account and why it makes any difference.
Re: Leif Svalgaard (19:20:27) “That is one reason.”
And the other part? Annual & semi-annual tides vs. annual & semi-annual variation in aa?
–
Resolving the misunderstanding appears to remain a fruitless endeavor.
Trying a more productive topic:
What caused the 1930s drought? (and would you answer this differently for the general public than for scientists?)
Paul Vaughan (20:09:36) :
And the other part? Annual & semi-annual tides vs. annual & semi-annual variation in aa?
For example, yes.
Resolving the misunderstanding appears to remain a fruitless endeavor.
Especially since you make no effort at all to make it fruitful. My question still stands.
What caused the 1930s drought? (and would you answer this differently for the general public than for scientists?)
I have no idea, but, no the answer [if I had one] would be the same, the exposition might be different, but if one really understands something, one can explain it to a five-year old.
Don Davis (19:16:17) :
So, the variation in the Earth’s distance from the Sun can be as big as +/-4.7%. This amounts to 18.8% variation in how much light we receive.
You have been misinformed [c.f. the danger of the Internet I spoke of]. The Earth and the Sun orbit their common center of mass, so the variation of the distance is just that resulting from the standard elliptical orbit. This follows from elementary physics, from careful numerical calculation, and from direct measurements of the TSI and [to stay on topic] the F10.7 radio flux that vary 7% over a year, and not 18.8%..
> The Earth and the Sun orbit their common center of mass, so the variation
> of the distance is just that resulting from the standard elliptical orbit.
My numbers were jumbled, but the Earth and the Sun both do orbit the solar
system’s barycenter. The corrected numbers are:
* Variation in radius of Earth’s eccentric orbit: +/-2.5e6 km (+/- 1.7%);
* Maximum radius of Sun’s orbit around the barycenter: 1.5e6km (+/- 1%).
These two numbers are well-known. Indeed, Oliver, in “Encyclopedia of world
climatology,” attributes the Solar-orbit radius calculation to Newton (p.256).
So, the total variation in sun-earth distance = +/-2.7%, and the consequent
variation in illumination = 10.8%.
> the F10.7 radio flux… vary 7% over a year, and not 18.8%.
The 10.8% variation in illuminance is a 20-year variation, so
the 7% annual variation in F10.7 flux doesn’t really bear on this.
Finally, eyeballing Wilds’ graph more carefully, I now see two periods between
1937 & 1987, so my eyeballed illuminance period should have been ~25 yr, not
20 yr. This, of course, does not match the 19.9yr Jupiter/Saturn synodic period.
Substantiating that claim would need a longer illuminance record than Wilds’.
Don Davis (12:05:24) :
My numbers were jumbled, but the Earth and the Sun both do orbit the solar system’s barycenter.
No they do not in the simple way you put it. The distance between the Sun and the Earth varies 3.3% year in and year out. There is no noticeable 20-year or other period in this. Often people cannot be convinced by logic or reason, so I’ll have to take to experiment. We have observed F10.7 for 60+ years and TSI for 30+ years and clearly and only see the 6.6% variation every year, no other period above the noise, except the 11-year solar cycle itself.
I know it’s late and you probably will not see this, but if you do, consider this website:
http://okc.mesonet.org
Watching regularly (I live in Oklahoma City), I can tell you that just after dusk is the premiere time to find the urban heat island, especially during the autumn. We have prevailing southerly winds, so the north end of the city tends to exhibit more urban heat effects than any other part (except sometimes downtown).
You can get actual data for the City micronet (unfortunately, the sensors are mounted on traffic signals in non-standard locations and non-standard heights) here:
http://www.mesonet.org/data/public/okc/
>> the Earth & the Sun both do orbit the solar system’s barycenter.
> No they do not in the simple way you put it. The distance between
> the Sun and the Earth varies 3.3% year in and year out.
dr. svalgaard,
i got this resolution of this dispute from an ex-nasa spacecraft-nav
physicist whom i know: the sun & the outer planets do indeed orbit
the barycenter. inside mars’ orbit. though, jupiter’s gravitational
gradient is roughly constant, so the inner planets all feel much the
same acceleration that the sun feels, towards jupiter. hence, while
the sun & the outer planets do orbit the solar system’s barycenter.,
the inner planets all behave approximately as if they were just
moons of the sun, orbiting the barycenter as an ensemble. finally,
saturn’s gravitational effect on the inner planers works just the same
as jupiter’s. so, this explains the flaw in my back-of-the-envelope
calculation.
Don Davis (14:52:12) :
the inner planets all behave approximately as if they were just
moons of the sun, orbiting the barycenter as an ensemble.
If you include the Sun in the ‘ensemble’ you are getting closer, but the explanation is still only a pseudo-explanation for the ‘unwashed masses’. The distinction between inner and outer planets is somewhat unphysical. Imagine you had only the Sun and the Earth, then there would be no problem, they orbit their common barycenter. Imagine the Sun was a double star with its companion at some distance [such as not to disrupt the Earth’s orbit]. Let the companion have the same mass as the Sun and also have a planet [with it and the star orbiting about their common barycenter]. Then the barycenter of the whole system would be halfway between the Sun and the star way outside the Earth’s orbit. Now add a Jupiter to each system, they will still orbit as ‘moons’ around their respective stars, and the barycenter of the whole system would still be halfway between the Sun and the star. Now slowly shrink the mass of the star and its planets. That would not upset the movements of the Earth and Jupiter that still move as ‘moons’ around the Sun. It would move the barycenter a bit closer to the Sun. Now also shrink the distance between the Sun and its star companion. In the end you can imagine that the star has become Jupiter, but at no time is there a point where the rules change. The rules for inner and outer planets are exactly the same. And at no time does any pair of the participants do anything else but orbit around the common barycenter of that pair. Anyway, if you can now see why your calculation was wrong, then the problem has been resolved, and we do need to look for 20-year modulations of TSI or F10.7, so all is well.
Leif Svalgaard (15:27:04) :
and we do not need to look for 20-year modulations of TSI or F10.7, so all is well
Re: Leif Svalgaard & Don Davis
Don, your explanation passes the 5-year-old comprehension-test (advocated above by Leif). Leif, yours does not (unless we restrict to a bright subset).
Towards a merger of Leif’s technical notes & Don’s narrative:
If ‘inner’ & ‘outer’ are physically-offensive categories, maybe “better” categories would be “MASSIVE & central”, “small & close”, and “big & far-out”. After all, we’re talking about weighted [by size & distance] averages.
My impression of what gets people confused when this topic arises: misleading pairwise focus.
Paul Vaughan (17:40:56) :
My impression of what gets people confused when this topic arises: misleading pairwise focus.
As usual, I am totally lost as to what you are trying to say.
And you have still not made any effort in explaining your misunderstanding. This is a very poor showing.
Paul Vaughan (17:40:56) :
Towards a merger of Leif’s technical notes & Don’s narrative
The oversimplification comes from the notion that some planets orbit the ‘solar system’ barycenter and others do not. In a sense none of them do, as the barycenter is just the mass-weighted average distance from an arbitrarily point the chosen origin of the coordinate system]. The gravitational attraction is between the Sun and the planet and that force is many orders of magnitude larger than that between a planet and any other planet, including Jupiter. So each planet and the Sun orbit their common barycenter
Leif Svalgaard (18:29:44) : continuation…
E.g. for the Earth the gravitational force between it and the Sun is Fse = Ms * Me/ De^2 = 333000 with units in Earth masses and distance in AU. Between the Earth and Jupiter on average Fje = Mj * Me / Dj^2 = 39 or 8,600 times smaller. It has nothing to do with ‘massive & central’ or ‘big & far-out’. Every body is a ‘moon’ of the Sun, inner or outer, bigger or close-in, or whatever.
Leif Svalgaard (18:41:59) : continuation…
So all the bodies move according to the combined mutual interactions. And seen from afar it is possible to calculate the center of gravity [barycenter] off all these bodies at any time and to refer the motion of each body with respect to that center, i.e. to choose that point as the origin of a coordinate system. Since forces from afar [e.g. the gravitational force of the Galaxy] acting an a collection of parts can be considered as acting on the center of mass, that point will be what is seen to move along its path in the Galaxy.
There is no inner-outer, massive-light, big-small, or what ever, divide. The solar system is a whole and the same rules work everywhere. I actually don’t see this as a mystery, and I have actually once explained it to a five-year old [number 2 here: http://www.leif.org/ ] and he had no problem with it.
Leif Svalgaard (18:29:44) “So each planet and the Sun orbit their common barycenter”
So exactly how many points do you have the sun oribiting in ‘this model’? [rhetorical question]
You’re making a lot more sense later when you speak of the “whole”.
– –
Leif Svalgaard (18:18:48) “This is a very poor showing.”
We are all volunteers. For example: I asked you a question 3.5 months ago & did not receive a reply.
– –
New Question:
What is your explanation for the 1930 spike in aa index?
Leif Svalgaard (19:19:38) “There is no inner-outer, massive-light, big-small, or what ever, divide.” / Leif Svalgaard (18:41:59) “It has nothing to do with ‘massive & central’ or ‘big & far-out’.”
You’re not making much sense here.
When teaching non-specialists at an introductory-level about weighted-averages, it is helpful to the students if I explain that a ‘heavily-weighted outlier’ has a large influence. [It’s no different in a spatial context.]
Obviously more precise measurement scales are used in calculations – if they are available …which they are in the example at hand – so the term ‘big’ used in the ‘WUWT lecture’ gets a more precise definition when the computing starts.
I’ve no doubt that the audience here realizes that the qualitative simplifications are for communication purposes.
Paul Vaughan (20:58:11) :
“This is a very poor showing.”
We are all volunteers. For example: I asked you a question 3.5 months ago & did not receive a reply.
Nonsense, you accused me of not taken into account the ‘central thesis’. I answered that I couldn’t see what that was, and asked you to tell me. You have spent an inordinate amount of volunteer time to avoid telling me. So, the question still stands.
What is your explanation for the 1930 spike in aa index?
The same as for the 1943, 1952, 1974, 1994, and 2003 spiles: very high-speed recurrent streams from large low-latitude coronal holes.
The solar wind speed for these years were:
1930: 521 km/s
1943: 517
1952: 518
1974: 527
1994: 518
2003: 535
The average solar wind speed is typically 426 km/s.
Similar spikes occurred in 1852, 1865, and 1886. They all share the distinction of occurring during the declining phase of the cycle.
Paul Vaughan (21:47:42) :
I’ve no doubt that the audience here realizes that the qualitative simplifications are for communication purposes.
I don’t think so. That this problem crops up all the time shows me that they do not understand the issue, and some take the simplifications to be real qualitative differences.
And what was her ‘central thesis’ that I should have paid attention to?
Leif Svalgaard (22:19:35) :
“The average solar wind speed is typically 426 km/s.
Similar spikes occurred in 1852, 1865, and 1886. They all share the distinction of occurring during the declining phase of the cycle.”
The Sun as a star emits by a factor of 1.5–2 more solar wind mass and energy
during solar minima in comparison with solar maxima years. Moreover, the overall
rising trend of the same order of magnitude during the past 30 years has been shown eg Veselovsky et al.2000 Richardson 1999
As this is connected with poloidal (i.e. open-field) component of solar magnetic field,whereas say CME peturbations of geomagnetic activity are at maximum a toroidal component (180 degrees out of phase) do we have a double driver? eg Ruzmaikin & Feynman (2001)
maksimovich (22:57:17) :
As this is connected with poloidal (i.e. open-field) component of solar magnetic field,whereas say CME peturbations of geomagnetic activity are at maximum a toroidal component (180 degrees out of phase) do we have a double driver? eg Ruzmaikin & Feynman (2001)
I don’t think so. These high-speed streams were feed by low-latitude coronal holes created from low-latitude active regions, so have little to do with the polar fields. There is a common misconception that these holes are ‘extensions’ of the the polar caps, that somehow droops down towards the equator. This is incorrect. The separation between poloidal and toroidal fields is somewhat arbitrary and often introduced for mathematical convenience, but has little significant physics behind it, the magnetic field is a ‘whole’.
Paul Vaughan (20:58:11) “We are all volunteers. For example: I asked you a question 3.5 months ago & did not receive a reply.”
Leif Svalgaard (22:19:35) “Nonsense”
You are mistaken. See here:
http://wattsupwiththat.com/2009/03/12/nasa-solicits-new-studie-on-the-current-solar-minimum/
[Paul Vaughan (12:05:05) Mar. 15, 2009]
– –
Leif Svalgaard (22:19:35) “[…] very high-speed recurrent streams from large low-latitude coronal holes.”
Thank you for conveying this useful information.
– –
Leif Svalgaard (22:26:01) “[…] some take the simplifications to be real qualitative differences.”
I will agree that for some it does not go beyond qualitative – and add that nonetheless scientists can (& do) try to help them establish accurate qualitative conceptions (within the existing constraints – e.g. available time).
– –
Re: maksimovich (22:57:17)
I remember turning up a presentation on this some time ago:
http://www.iono.noa.gr/cost724/Documents/WG1/Th_Dudok_de_Wit.pdf
From the presentation: “The method is simple yet the fit is better than any one produced so far”
Paul Vaughan (23:38:39) :
“We are all volunteers. For example: I asked you a question 3.5 months ago & did not receive a reply.”
You are mistaken. See here:
I would be curious to know what Dr. Svalgaard believes might be responsible for the 7.8 year signal detected in European temperature time series
I didn’t see a question mark in there and I don’t have an opinion. My ‘nonsense’ went to the “we are all volunteers” excuse. How many times have I asked you now what ‘the central thesis’ was? and how many times have you squirmed to avoid an answer? and now this lame excuse. Are you not a bit ashamed of yourself? So, tell me what ‘her central thesis’ was and how that should have changed my position vis-a-vis her papers. Looking forward to your next excuse for avoiding that issue.
Leif Svalgaard (23:59:00) “I don’t have an opinion.”
Double-standard.
Leif Svalgaard (18:23:34) :
Allan M R MacRae (16:58:30) :
BTW, some time ago I sent you a paper by Jan Veizer (GAC 2005) that in Figure 2 showed an apparently strong correlation between Cosmic Ray Flux and Low Cloud cover, (after Marsh and Svensmark 2003 and Marsh et al 2005). Did you get this paper? Do you accept or reject this correlation?
It doesn’t look too good, and employs a standard technique of persuasion, namely plotting some other quantities as well that are well correlated to ‘guide’ the eye. Svensmark notes that perhaps a better calibration of the spacecraft data would improve the correlation. The recent albedo data of Palle also do not support the correlation, as there is no clear solar signal.
_________________________________
Leif, I have re-examined Figure 2 of Veizer (2005) and cannot agree with your above comment. I tend to agree with Veizer, when he says:
Figure 2. Solar irradiance (SI), galactic cosmic ray (CR) flux and low cloud (LC) cover, 1983 – 2001 (adapted from Marsh and
Svensmark, 2003a and Marsh et al., 2005). Note the reversed scale for SI. Some authors (Laut, 2003) argue that the apparent
post-1995 divergence of clouds from celestial trends disqualifies the correlations. However, the discrepancy may arise from a
modified cross-calibration of satellites, following the late 1994 hiatus in polar orbit flights (Marsh and Svensmark, 2003a). A correction
for this drift (thick full line LC’) results in a good agreement for all parameters (see also Pallé et al., 2004b and Usoskin
et al., 2004).
_____
I have not reviewed Pallé.
We’ll see where this leads. Just because we do not understand the mechanisms whereby solar variation (or whatever) drive climate variability, does not mean that they do not exist.
Paul Vaughan (00:56:49) :
Leif Svalgaard (23:59:00) “I don’t have an opinion.”
Double-standard.
Because I have not read the paper.
So, tell me what ‘her central thesis’ was and how that should have changed my position vis-a-vis her papers.
Allan M R MacRae (02:27:07) :
Just because we do not understand the mechanisms whereby solar variation (or whatever) drive climate variability, does not mean that they do not exist.
I thought the whole point of the GCR-hypothesis was that they do understand and provide the mechanism. My criticism was of that particular mechanism and what goes for evidence for it.
Leif Svalgaard (07:15:05) “Because I have not read the paper.”
Now you are contradicting yourself.
Paul Vaughan (08:33:26) :
Leif Svalgaard (07:15:05) “Because I have not read the paper.”
Now you are contradicting yourself.
Or don’t remember the paper or didn’t think it worthwhile, or whatever.
So, tell me what ‘her central thesis’ was and how that should have changed my position vis-a-vis her papers.
Paul Vaughan (08:33:26) :
Leif Svalgaard (07:15:05) “Because I have not read the paper.”
Now you are contradicting yourself.
“Or don’t remember the paper or didn’t think it worthwhile, or whatever.”
Or better, I’ll make a deal with you. If my humble opinion about that paper is so important to you that you remember it and it still nags you after 3.5 months, then provide a free link to the paper. I’ll read it and render my opinion on it. In return, you’ll be uncharacteristically constructive and ‘tell me what ‘her central thesis’ was and how that should have changed my position vis-a-vis her papers.’.
Deal?
Sometimes, as a teacher, you have to let the student save face in order to go on to the next lesson. What you say today may not reach into the inner core of understanding till much later after further lessons have been given. Then suddenly (or slowly) past arguments give way to ah ha moments and the student is grateful for the patience and tolerance of the teacher back then.
I have been tutored by both kinds of teachers, the ones that insist that every step be taken in and understood before further progress can be made (even if that means staying after school to discover the difference between /of/ and /off/ in the first grade), and the ones that take a break from long division to teach how to make bread with her 4th grade students. Strangely enough, the ah ha moment came while eating warm bread, not during the math lesson.
Pamela Gray (09:51:31) :
Sometimes, as a teacher, you have to let the student save face in order to go on to the next lesson.
Pamela, those are wise words. In the current “Physics Today” Helen Quinn has this observation “One key to progress in science is an eye for contradictions and an insistence that they be resolved. That can make scientists seem overly dogmatic or argumentative in the eyes of a nonscientist because it diverges strongly from usual human behavior”. Perhaps it is time to let the student [Paul V] of the hook and let his ah-ha moment come to him on his own.
Re: Leif Svalgaard (09:08:06) & Leif Svalgaard (09:50:57)
You claimed earlier to be familiar with all of Dr. Charvatova’s work – stating it was your responsibility.
You’ve contradicted yourself again.
You put words in my mouth and pester me to [re-]answer a question about a researcher, but you’ve also avoided addressing my inquiry about the work of the same researcher for 3.5 months.
Double-standard.
–
Leif Svalgaard (09:50:57) “[…] it still nags you […]”
It doesn’t “nag” – you’re a volunteer.
However, since you persist with harassing comments, I’m pointing out your double-standard & self-contradictions.
– –
Re: Pamela Gray (09:51:31) & Leif Svalgaard (10:34:17)
These matters are interdisciplinary. No single discipline has a monopoly. For example, statistical missteps by top experts (including physicists) are not so rare.
Optimistic adages:
1) Adapt & overcome.
2) Turn your disadvantage into your advantage.
This could take time, as Pamela has pointed out. I would add that we are all eternal students.
– –
Is anyone interested in discussing DTR and the article featured in this thread?
Paul Vaughan (13:10:14) :
You claimed earlier to be familiar with all of Dr. Charvatova’s work – stating it was your responsibility.
You’ve contradicted yourself again.
You put words in my mouth and pester me to [re-]answer a question about a researcher, but you’ve also avoided addressing my inquiry about the work of the same researcher for 3.5 months.
Double-standard.
You could distance yourself from trying to emulate my double standard and try to give me the answer that I seek. My deal still stands. At the time of the reviews I had looked ‘again’ at her work. Most of it was of the quality that bears to be quickly forgotten, so not necessarily a contradiction. You are welcome to post a free link to the paper so I can you the opinion you so eagerly seek.
However, since you persist with harassing comments, I’m pointing out your double-standard & self-contradictions.
You have still not answered my question. Is is harassment to want to know on what you base a criticism of me? I think not.
Or should I allow the student to save face as Pamela suggests.
Leif, I’m not sure what illusions you imagine people to be under, but if there is something specific you wish to teach, I’ll read it.
Also, if you would like to discuss the DTRs and the article that is the topic of this thread, I can spare time for that.
Paul Vaughan (14:17:11) :
Leif, I’m not sure what illusions you imagine people to be under, but if there is something specific you wish to teach, I’ll read it.
No, I just want to know what her ‘central thesis’ is and why that was important.