new paper in GRL confirms link between sun and clouds on global scale

Wagmc

The major conclusion: “A link between the Sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale…”

http://docs.google.com/gview?a=v&q=c...0,file%3D11877

keep in mind that solar modulation of clouds of even 2-3 percent will account for all warming seen since 1900. No CO2 required...

Skyhunter

If there is such a link... then why during the current low solar minimun and associated increase in GCRs penetrating to lower altitudes, are temperatures still at record highs?

Xnn

VERY WRONG!

The problem with the quoted statement is that cloudiness has actually been on the increase.
The increase in cloud cover has changed the earths albedo and actually decreased the
amount of sunlight reaching the earths surface. This has resulted in about
a loss of 1 kw/m^2 warming. In other words there has actually been a slight cooling
of the earth due to the increase in clouds. If cloudiness had not increased, then
the amount of warming would have been greater than it has.

See page 136 of the following link:

http://www.ipcc.ch/pdf/assessment-re...1-chapter2.pdf

All that the original paper has shown is that there has been a slight (2-3 sigma) and temporary decrease in low level clouds for a few days after the largest cosmic ray events. There has only been about 2 dozen of these events over the last 20 years and no real trend.

The long term influence of cosmic rays on the climate is minor and has been completely overwhelmed by the long term rise in greenhouse gases; primarily CO2 and CH4.

Wagmc

@ sky

Oceans hold a lot of heat. It is expected that changes in cloud cover will take 7-15 years to manifest themselves as atmospheric temperature changes.

And even though we are currently in an unusually deep and prolonged minimum, keep in mind that overall solar activity is still at a grand maximum compared to the previous 1,000 years. The five strongest solar cycles ever recorded have occurred in the last ~50 years. It is no surprise that temperatures remain high.

The fact that cycles 22 and 23 were less active than 21 - and that global temperatures have stabilized or probably cooled - should give one pause when considering CO2 as the main driver of global temperatures. 24 will tell this tale, no?

@Xnn

The importance of this paper is that is provides evidence of a direct, observable and measureable link between solar magnetic activity and cloud cover. That solar magnetic activity varies in conjunction with other solar parameters (TSI) is well established. It is also clear that long-term variations in global cloud cover vary in time with these magnetic changes. What has been missing is a causal mechanism. This paper is an important step in tht direction.

You seem to hold to the belief that whatever the IPCC says is written in stone and not subject to debate? That this study disagrees with the IPCC conclusion is irrelevant. New information invalidates old information. Observations always trump models. Whatever the IPCC said has now been shown to be incorrect.

Some other interesting reading. Many of these were not considered by the IPCC There are dozens more:

Shaviv, N. J., ( 2005). "On Climate Response to Changes in the Cosmic Ray Flux and Radiative Budget", JGR-Space, vol. 110, A08105.’

Scafetta, N., West, B.J. (2006). Phenomenological Solar Signature in 400 years of Reconstructed Northern Hemisphere Temperature Record”, GRL.

SOLANKI,S. K. and Fligge, M. 1998. Solar irradiance since 1874 revisited. Geophysical Research Letters, 25: 341-344.

SOLANKI, S.K., Usoskin, I.G., Kromer, B., Schüssler, M. and Beer, J. 2005. Unusual activity of the Sun during recent decades compared to the previous 11,000 years. Nature 436: 174 (14 July 2005) doi: 10.1038/436174b

Dergachev, V.A., Dmitriev, P.B., Raspopov, O.M. and Jungner, H. 2006. Cosmic ray flux variations, modulated by the solar and earth's magnetic fields, and climate changes. 1. Time interval from the present to 10-12 ka ago (the Holocene Epoch). Geomagnetizm i Aeronomiya 46: 123-134.

Lockwood, M., and R. Stamper, 1999: Long-term drift of the coronal source magnetic flux and the total solar irradiance. Geophys. Res. Lett., 26, 2461-2464.

Perry, C.A., Evidence for a physical linkage between galactic cosmic rays ..., J. Adv. Space Res. (2007), doi:10.1016/j.asr.2007.02.079

Kirkby, J. 2008. Cosmic rays and climate. Surveys in Geophysics 28: 333-375.
Concludes: Numerous palaeoclimatic observations, covering a wide range of time scales, suggest that galactic cosmic ray variability is associated with climate change. The quality and diversity of the observations make it difficult to dismiss them merely as chance associations. But is the GCR flux directly affecting the climate or merely acting as a proxy for variations of the solar irradiance or a spectral component such as UV? Here, there is some palaeoclimatic evidence for associations of the climate with geomagnetic and galactic modulations of the GCR flux, which, if confirmed, point to a direct GCR-climate forcing. Moreover, numerous studies have reported meteorological responses to short-term changes of cosmic rays or the global electrical current, which are unambiguously associated with ionising particle radiation.

CRGreathouse

Give us some numbers to play with. How much heat do you attribute to a solar cycle -- say from the median to the most extreme of those five?

Skyhunter

Where is this 7-15 year lag in the Svensmark's other claims to the GCR climate connextion?

Give me 8 years of leeway and I could find a correllation to almost anything.

As for the paper itself... 5 events and 26 data points???

Here is a more complete paper that finds no correlation.

Xnn

WRONG AGAIN!

Cloud cover has been increasing because increased levels of GHGs allow the atmosphere to hold more moisture. This has been the long term trend over the last 50 years.

Solar activity is currently at a 50 year minimum. If anything, the lack of solar activity should lead to less cloud cover. However, we are observing just the opposite. These solar theories have been shown repeatedly to lack significance.

Regarding the IPCC, if you take the time to actually read the report, you'll find that there are many areas of climate science where the level of understanding is low.

Wagmac; what you are proposing doesn't make sense or even agree with observations.

Wagmc

@Xnn: Solar activity is at a 50 year minimum, after a 1,000 year grand maximum. And you will note that temps are falling.

So you admit that cloud feedbacks from warming have been observed to be a net negative feedback. As opposed to positive feedbacks claimed by IPCC? But, I digress...

However, thank you for making my point. You have the solar influence exactly backward. A less active sun produces less magnetic protection, allowing more GCR to strike earth. More GCR means more clouds. Exactly what you say is occurring. Thus, the link is confirmed. Thank you.

In light of at least 35 studies in the last 5 years citing observation and measurement of a significant solar influence on climate, it is the CO2 driven warming theories that are demonstrating a lack of significance.

@Sky: Wigley (1988) found a 3-5 year lag. Hoyt & Schatten (2005) found the highest correlation with a 3 year lag. Scafetta & West (2003) put it at 6-12 years.

Again, Sky, you don't bother to even read the study. Svensmark references the flaws in Kristjnsson et al. directly. I won't even bother to address this further.

@ Greathouse:

Scafetta & West (2006) put the solar impact at least 50% of observed warming.

Pinker (2005) and Wild (2005) quantify changes in radiation reaching earth's surface as increasing by 2.7 W/m2 and 4.4 W/m2 respectively, compared with the IPCC's estimate of greenhouse forcing of 2.4 W/m2. This puts the change in solar radiation at at least 50% of warming.

Beer (2000) puts it at 40%. Still almost half.

Scafetta & West (2008) ups their estimate to 70% solar.

And ALL these studies rely only on measures of TSI. NONE of them address indirect (magnetic) effects as studied by Svensmark. This will only serve to increase the amount of warming attiributable to solar changes.

Skyhunter

Please note that temps are not falling. The last decade is the warmest decade in the instumental record, and last month was the second warmest June on record, with SSTs being the warmest ever recorded for the month of June.

A 3 year lag, a 6-12 year lag or a 7-15 year lag. Such a huge disparity brings all the estimates into question. But since TSI peaked in 1960, none of them explain the 59+ years warming trend.

No need to cast aspersions against me. I did read the eight page study you linked. They mention Kristjnsson once on page three to acknowledge that Kristjnsson did not find a correlation. How you can interpret that as addressing flaws is beyond me.

The paper is very short on details or explanations. It appears that they looked for, and found a correlation to fit their argument with little to no explanation as to why these are the expected results. They do not go into detail as to why the filtering they used provides a robust analysis or why the lag between FD and CWC, or how these tiny aerosols become CCN. Since a clouds lifetime is measured in hours I fail to see how these FD events can be linked to CWC a week later, especially wihout considering the weather patterns during the 7 day interval.

It is an interesting paper, but very short on details. It is only a confirmation of the cloud GCR link to one who already has a bias in need of confirmation.


Apples and oranges. Surface flux is more a function of aerosols and related more to atmospheric composition than solar flux. You are misapplying these papers to make claims the authors do not.

As I pointed out Pinker and Wild are not measuring TSI, they are measuring surface flux not radiative forcing, so we can right away discard those studies as supporting your premise.

The change in TSI from the Maunder Minimum to the Modern Maximum is ~.2%. So (340Wm² x 0.02 = 0.68Wm²) It is impossible for such small fluctuations in the solar constant alone to account for the warming of the last 50 years.

Andre

That may not be the general impression

Xnn

http://www.ncdc.noaa.gov/sotc/?report=global


Oceans temperatures were at all time highs for the Month of June with 2005 as the second warmest.

Land temps were the 6th warmest; the warmest being June 2005.

Saul

Cloud cover has been decreasing in the later part of the 20th century not increasing based on observations, not GHG models. This finding is supportive of Palle's papers on earthshine and satellite based planetary cloud cover analysis.

As the solar magnetic cycle appears to be interrupted (GCR is now increasing and I would assume as there are blue spots in the ocean surface temperature data, there is in response to increasing GCR, increasing cloud cover over the ocean which is ion poor.) we will be able to determine by observation how much of the 20th century warming was due to decreased cloud cover and how much was due to GHG.


http://www.atmos-chem-phys.org/5/172...1721-2005.html

Analysis of the decrease in the tropical mean outgoing shortwave radiation at the top of atmosphere for the period 1984–2000

Skyhunter

This is science not politics. Perception is not reality.

Andre

look again

Wagmc

GISS is the only measure that reports still increasing temperatures. It has been well established that their land measurements are contaminated by UHI. GISS is the outlier.

Reading any of the other three major temperature measures gives a completely different picture.

You are free to publish a rebuttal.

You are making a strawman argument. I provided a list of studies that present measures of changes in solar activity related to changes in global temperature. "What" a particular study is measuring is less relevant than the fact that continued observations indicate that yes, solar activity does change and, yes, it is a major driver of global temperatures.

Since prior to 1940 the ONLY source of changes in global temperature were these "small fluctuations," it would appear on first examination that your claim of "impossiblity" is incorrect. There could be no other cause, therefore these small changes MUST influence temperature.

Second, the studies previously referenced present evidence that contradicts you.

Third, you continue to ignore that UV varies as much as 6% and has recently implicated in ozone destruction (an exothermic process). Likewise, TSI does not measure indirect, magnetic effects, which was the subject of the OP. These indirect effects will be in addition to changes in TSI.

The continued increase in temps since the solar peak "50 years ago" is another strawman. You will note that the relatively weak cycle 20 was associated with "the cooling 70's." It was followed by three of the five strongest cycles ever recorded. That temperatures continued to rise is no surprise. If you turn the burner to high, and then turn it down to medium the pan will continue to warm if it had not reached equilibrium before you turned down the heat. physics 101.

Skyhunter

Look at what? A bunch of blogs?

No thanks. I will stick with NOAA, where real science is conducted.

Andre

Here is one of those papers.



here are figs. one and two respectively showing the global cloud cover and the correlation with the albedo fluctuation measured on the reflection of the dark side of the moon.

They note the trend reversal around 1998-1999 and hence wonder...

as obviously the higher the albedo the more visible light is reflected and the lower the temperatures. They do some proposals however they fail to do the obvious and that is to compare the albedo trend with the actual global temperature trend. That would have revealed that the temperature trend also changed in the same period and I bet we would find a very nice correlation between actual temperatures and actual measured albedo if it was allowed here to show some own work.

and temperatures corrolating with global albedo would again take some explaining away from other factors like greenhouse effect for instance.