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

[Xnn]

IPCC The Physical Science Basis

Chapter 3; Observations: Surface and Atmospheric Climate Change

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter3.pdf

Page 275-277 Section 3.4.3 Clouds

As noted in the TAR and extended with more recent studies,
surface observations suggest increased total cloud cover since
the middle of the last century over many continental regions
including the USA (Sun, 2003; Groisman et al., 2004; Dai et
al., 2006), the former USSR (Sun and Groisman, 2000; Sun et
al., 2001), Western Europe, mid-latitude Canada, and Australia
(Henderson-Sellers, 1992). This increasing cloudiness since
1950 is consistent with an increase in precipitation and a
reduction in DTR (Dai et al., 2006). However, decreasing
cloudiness over this period has been reported over China
(Kaiser, 1998), Italy (Maugeri et al., 2001) and over central
Europe (Auer et al.,2007). If the analyses are restricted to after
about 1971, changes in continental cloud cover become less
coherent. For example, using a worldwide analysis of cloud
data (Hahn and Warren, 2003; Minnis et al., 2004) regional
reductions were found since the early 1970s over western Asia
and Europe but increases over the USA.

In summary, while there is some consistency between
ISCCP, ERBS, SAGE II and surface observations of a reduction
in high cloud cover during the 1990s relative to the 1980s, there
are substantial uncertainties in decadal trends in all data sets
and at present there is no clear consensus on changes in total
cloudiness over decadal time scales.

 

[Xnn]

http://www.ncdc.noaa.gov/sotc/

The global ocean surface temperature for July 2009 was the warmest on record, 0.59°C (1.06°F) above the 20th century average of 16.4°C (61.5°F). This broke the previous July record set in 1998. The July ocean surface temperature departure from the long-term average equals June 2009 value, which was also a record.

June and July were both record high ocean temperatures!

 

[Skyhunter]

http://www.ncdc.noaa.gov/sotc/

June and July were both record high ocean temperatures!

The http://www.ncdc.noaa.gov/sotc/?report=global#tropo" is also beginning to warm.

UAH ranks the lower troposphere second warmest, while RSS ranks it third.

Both rank the mid troposphere second warmest with the University of Washington's analysis to remove stratospheric influence.

With the developing El Nino, 2009 could very well set a new global record.

If El Niño conditions continue to mature, as now projected by NOAA, global temperatures are likely to exceed previous record highs.

 

[Xnn]

Here is a listing of monthly ocean temperature anomalies from the NCDC.

ftp://ftp.ncdc.noaa.gov/pub/data/anomalies/monthly.ocean.90S.90N.df_1901-2000mean.dat[/URL]

Please Note: Anomalies are provided as departures from the 20th century average (1901-2000).

1997 1 0.2577
1997 2 0.3093
1997 3 0.3585
1997 4 0.3391
1997 5 0.4152
1997 6 0.4887
1997 7 0.4885
1997 8 0.5023
1997 9 0.5528
1997 10 0.5603
1997 11 0.5481
1997 12 0.5776
1998 1 0.5613
1998 2 0.5616
1998 3 0.5493
1998 4 0.5569
1998 5 0.5603
1998 6 0.5775
1998 7 0.5761
1998 8 0.5632
1998 9 0.4368
1998 10 0.3901
1998 11 0.4149
1998 12 0.3560

Now compare that to this year:

2009 1 0.3580
2009 2 0.3442
2009 3 0.3817
2009 4 0.4293
2009 5 0.4760
2009 6 0.5695
2009 7 0.5924


First, June 2009 wasn't exactly a record compared to 1998.
However, they just changed their methods, so maybe it was a record by the old methods, but isn't exactly a record any longer. Either way, it was the warmest month for the global ocean for several years.

Also, the 97/98 El Nino started about the same time of year in 1997.
It was unusually strong and got even warmer in 1998.
Of course, no way to know if this latest El Nino will be as long and strong or not.
If it is, then 2010 may well be a record year as well.

 

[Xnn]

Notice: No UHI for the Ocean Temperatures!

 

[dorlomin]

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

We are also at the weakest values for solar insolation in the far nothern lattitudes for several thousand years. Orbital forcing suggests that we should be experiancing the furthest extents of the arctic ice pack and summer snow pack for millenia, this should be reflecting energy and giving us the lowest temperatures since before the holocene climate optimum.

The five strongest solar cycles ever recorded have occurred in the last ~50 years. It is no surprise that temperatures remain high.

The strongest in terms of sunspots was in the late 50s. Yet the 60s and 70s seen a slight drop in temperatures.

 

[dorlomin]

One more question how does this theory tie in with the drop in pan evaporation rates since the mid 20th centuary at least and its slight reversal since the 90s. Is this not the opposite of what should happen?

 

[Wagmc]

"weakest values for solar insolation" is not consistent with grand maximum of solar activity. If you are referring to orbital influences, it could be that increased solar activity is more than sufficient to offset the minor insolation change. And that when (not if) solar activity declines, we will be in for additional cooling, no? Can you provide references for insolation changes from orbital variation?

"Yet the 60s and 70s seen a slight drop in temperatures"

Yes, and you will note that cycle 20 was less active than cycle 19.

 

[dorlomin]

"weakest values for solar insolation" is not consistent with grand maximum of solar activity. If you are referring to orbital influences, it could be that increased solar activity is more than sufficient to offset the minor insolation change. And that when (not if) solar activity declines, we will be in for additional cooling, no? Can you provide references for insolation changes from orbital variation?

You can try here for the data
http://www.ncdc.noaa.gov/paleo/pubs/huybers2006b/huybers2006b.html

But graphs here

And here

Its anything but insignificant.

"Yet the 60s and 70s seen a slight drop in temperatures"

Yes, and you will note that cycle 20 was less active than cycle 19.

This is the HADCRUT 3 temperature data set.

The 40s were warmer than the 50s. The 50s had the strongest sun cycle of the century but you would not guess that from the temperature data.

 

[Xnn]

Great post dorlomin;

Monthly sunspot numbers can be found here:

http://solarscience.msfc.nasa.gov/greenwch/spot_num.txt

Currently we are looking at 19 consecutive months where the number of sunspots have been less than 10. In some months it has been less than 1.

The sun hasn't been this quiet since around 1912/1913. While global temperatures were unusually cool during that period, the same can't be said for the present!

 

[Skyhunter]

If the GCR/climate connection were as strong as posited by Svensmark, then we should be experiencing a dramatic drop in global temperatures as GCR is 19% higher than during the Modern Solar Maximum.

http://science.nasa.gov/headlines/y2009/images/cosmicrays/GCR_Fe_SolCyc2009.6Lin.jpg

http://www.nasa.gov/topics/solarsystem/features/ray_surge.html
http://science.nasa.gov/headlines/y2009/29sep_cosmicrays.htm

 

[Saul]

If the GCR/climate connection were as strong as posited by Svensmark, then we should be experiencing a dramatic drop in global temperatures as GCR is 19% higher than during the Modern Solar Maximum.

http://www.nasa.gov/topics/solarsystem/features/ray_surge.html
http://science.nasa.gov/headlines/y2009/29sep_cosmicrays.htm

Skyhunter,

You do not understand the mechanisms by which solar changes modulate planetary cloud cover.

Solar wind bursts remove cloud forming ions by a process that is called "electroscavenging". GCR is high currently however solar wind bursts are also three times higher than normal. The solar wind burst are removing the cloud forming ions. The solar wind bursts are also removing magnetic flux from the sun which will weaken the next cycle.

The solar wind bursts are now starting to abate, so we should and are seeing increased colder weather in both hemispheres.

See section 5a) Modulation of the global circuit in this review paper that explains how solar wind bursts increases in the global electric circuit hence removing cloud forming ions. Somewhat interesting solar wind burst increased by a factor of 2.5 in the later part of the 20th century in a manner that directly correlates with the warming and cooling of the later part of the 20th century.

The same review paper summarizes the data that does show correlation between low level clouds and GCR.

http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf


http://www.agu.org/pubs/crossref/2009/2009JA014342.shtml

If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals.

Observations from the recent Whole Heliosphere Interval (WHI) solar minimum campaign are compared to last cycle's Whole Sun Month (WSM) to demonstrate that sunspot numbers, while providing a good measure of solar activity, do not provide sufficient information to gauge solar and heliospheric magnetic complexity and its effect at the Earth. The present solar minimum is exceptionally quiet, with sunspot numbers at their lowest in 75 years and solar wind magnetic field strength lower than ever observed. Despite, or perhaps because of, a global weakness in the heliospheric magnetic field, large near-equatorial coronal holes lingered even as the sunspots disappeared. Consequently, for the months surrounding the WHI campaign, strong, long, and recurring high-speed streams in the solar wind intercepted the Earth in contrast to the weaker and more sporadic streams that occurred around the time of last cycle's WSM campaign.

 

[Saul]

Great post dorlomin;

Monthly sunspot numbers can be found here:

http://solarscience.msfc.nasa.gov/greenwch/spot_num.txt

Currently we are looking at 19 consecutive months where the number of sunspots have been less than 10. In some months it has been less than 1.

The sun hasn't been this quiet since around 1912/1913. While global temperatures were unusually cool during that period, the same can't be said for the present!

Xnn,

See my comment to Skyhunter. You also do not understand the mechanisms by which the sun modulates planetary cloud cover.

This is scientific forum. You must first understand the competing mechanism before disagreeing with the mechanism.

I found the same problem at Real Climate. The writers and those people posting there did and do not understand electroscavenging.

Electroscavenging is the name for the process by which solar wind bursts remove cloud forming ions. (See my comment above that has a link to Tinsley and Yu review paper of the science of cloud formation.) I note the GCM do not model clouds and the IPCC report notes modeling clouds is the greatest uncertainty in the GCM.

http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf

Once again about global warming and solar activity K. Georgieva, C. Bianchi, and B. Kirov

We show that the index commonly used for quantifying long-term changes in solar activity, the sunspot number, accounts for only one part of solar activity and using this index leads to the underestimation of the role of solar activity in the global warming in the recent decades. A more suitable index is the geomagnetic activity which reflects all solar activity, and it is highly correlated to global temperature variations in the whole period for which we have data.

In Figure 6 the long-term variations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataja 2003). The correlation between the two quantities is 0.85 with p<0.01 for the whole period studied.It could therefore be concluded that both the decreasing correlation between sunspot number and geomagnetic activity, and the deviation of the global temperature long-term trend from solar activity as expressed by sunspot index are due to the increased number of high-speed streams of solar wind on the declining phase and in the minimum of sunspot cycle in the last decades.

 

[Saul]

Incidentally, Solar Activity in the 20th century was the highest in 8,000 years.

http://cc.oulu.fi/~usoskin/personal/nature02995.pdf

GCR reduced by a factor of 7 and 9 in the 20th century. Lowest in 1100 years.

http://hesperia.gsfc.nasa.gov/sspvse/oral/Ken_McCracken/wintergreen1.pdf


Doubling Sun’s Coronal Magnetic Field in Last 100 years

http://www.nature.com/nature/journal.../399437a0.html

The solar wind is an extended ionized gas of very high electrical conductivity, and therefore drags some magnetic flux out of the Sun to fill the heliosphere with a weak interplanetary magnetic field1,2. Magnetic reconnection—the merging of oppositely directed magnetic fields—between the interplanetary field and the Earth's magnetic field allows energy from the solar wind to enter the near-Earth environment. The Sun's properties, such as its luminosity, are related to its magnetic field, although the connections are still not well understood3,4. Moreover, changes in the heliospheric magnetic field have been linked with changes in total cloud cover over the Earth, which may influence global climate5. Here we show that measurements of the near-Earth interplanetary magnetic field reveal that the total magnetic flux leaving the Sun has risen by a factor of 1.4 since 1964: surrogate measurements of the interplanetary magnetic field indicate that the increase since 1901 has been by a factor of 2.3. This increase may be related to chaotic changes in the dynamo that generates the solar magnetic field. We do not yet know quantitatively how such changes will influence the global environment.

 

[Skyhunter]

Skyhunter,

You do not understand the mechanisms by which solar changes modulate planetary cloud cover.

No one understands if or how solar changes modulate planetary cloud cover, but it is a moot point since http://www.nasa.gov/topics/solarsystem/features/ray_surge.html"

The solar wind is flagging. "Measurements by the Ulysses spacecraft show that solar wind pressure is at a 50-year low"

Solar wind inflates the solar magnetic field that shields the Earth from GCR. If the wind were 3 times normal, then GCR flux would be low... not ~20% above normal.

The GCR/cloud connection is still an unproven hypothesis. Scientists are unsure it even exists and if it does, what if any climate impact it would have. The paper you cite offers what the authors call, "possible explanations." However they rely on Svensmark 1997 for their measure of total cloud cover. As http://stephenschneider.stanford.edu/Publications/PDF_Papers/Laut2003a.pdf" Svensmark confused total cloud cover with water clouds only. Therefore, I am somewhat skeptical of their results since they show correlation based on a flawed set of physical parameters.

It is fine to have a pet theory, just don't get worked up when others are skeptical of implausible claims.

 

[Saul]

No one understands if or how solar changes modulate planetary cloud cover, but it is a moot point since http://www.nasa.gov/topics/solarsystem/features/ray_surge.html"


Solar wind inflates the solar magnetic field that shields the Earth from GCR. If the wind were 3 times normal, then GCR flux would be low... not ~20% above normal.

It is fine to have a pet theory, just don't get worked up when others are skeptical of implausible claims.

Skyhunter,

I am sorry there is something incorrect with the AWG hypothesis, as global warming is preferable to abrupt cooling. The solar wind bursts are abating GCR has increased by a 19% and the magnitude of the strongest GCR has increased by a factor of 5.

GCR also removes high altitude clouds which results in record cold temperatures at high latitudes. The record cold is required to thicken the sea ice such that it will not melt in the summer. I see a record low has been set on the Greenland Ice sheet for September., 2009. This would be interesting if I did not live at high latitudes in a Mountainous region.

You are looking at this problem emotionally rather than as a science problem.

Try reading this paper by Nir Shaviv.


http://arxiv.org/abs/physics/0409123


On climate response to changes in the cosmic ray flux and radiative budget by Nir J. Shaviv

We examine the results linking cosmic ray flux (CRF) variations to global climate change. We then proceed to study various periods over which there are estimates for the radiative forcing, temperature change and CRF variations relative to today. These include the Phanerozoic as a whole, the Cretaceous, the Eocene, the Last Glacial Maximum, the 20th century, as well as the 11-yr solar cycle. This enables us to place quantitative limits on climate sensitivity to both changes in the CRF, Phi_CR, and the radiative budget, F, under equilibrium. Under the assumption that the CRF is indeed a climate driver, we find that the sensitivity to CRF variations is consistently fitted with mu := -Phi_0 (dT_global/ d Phi_CR) = 6.5 +/- 2.5 K (where Phi_0 is the CR energy flux today). Additionally, the sensitivity to radiative forcing changes is lambda := dT_global/ dF_0 = 0.35 +/- 0.09 K/(W/m^2), at the current temperature, while its temperature derivative is negligible with d lambda / dT_0 = 0.01 +/- 0.03 1/(W/m^2). If the observed CRF/climate link is ignored, the best sensitivity obtained is lambda = 0.54 +/- 0.12 K/(W/m^2) and d lambda / dT_0 = -0.02 +/- 0.05 1/(W/m^2). The CRF/climate link therefore implies that the increased solar luminosity and reduced CRF over the previous century should have contributed a warming of 0.37+/-0.13 K, while the rest should be mainly attributed to anthropogenic causes. Without any effect of cosmic rays, the increase in solar luminosity would correspond to an increased temperature of 0.16+/-0.04 K.

 

[Saul]

No one understands if or how solar changes modulate planetary cloud cover, but it is a moot point since http://www.nasa.gov/topics/solarsystem/features/ray_surge.html"
Solar wind inflates the solar magnetic field that shields the Earth from GCR. If the wind were 3 times normal, then GCR flux would be low... not ~20% above normal.

The GCR/cloud connection is still an unproven hypothesis. Scientists are unsure it even exists and if it does, what if any climate impact it would have. The paper you cite offers what the authors call, "possible explanations." However they rely on Svensmark 1997 for their measure of total cloud cover. As http://stephenschneider.stanford.edu/Publications/PDF_Papers/Laut2003a.pdf" Svensmark confused total cloud cover with water clouds only. Therefore, I am somewhat skeptical of their results since they show correlation based on a flawed set of physical parameters.

Here are some more papers. The rebuttals are also interesting.

http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf

Celestial driver of Phanerozoic climate?

Atmospheric levels of CO2 are commonly assumed to be a main driver of global climate. Independent empirical evidence suggests that the galactic cosmic ray flux (CRF) is linked to climate variability. Both drivers are presently discussed in the context of daily to millennial variations, although they should also operate over geological time scales. Here we analyze the reconstructed seawater paleotemperature record for the Phanerozoic (past 545 m.y.), and compare it with the variable CRF reaching Earth and with the reconstructed partial pressure of atmospheric CO2 (pCO2). We find that at least 66% of the variance in the paleotemperature trend could be attributed to CRF variations likely due to solar system passages through the spiral arms of the galaxy.

http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmReplyReply.pdf


Further response to “Cosmic Rays, Carbon Dioxide and Climate” by Rahmstorf et al.



Detailed Response to Royer et al.’s letter “CO2 as a primary driver of Phanerozoic Climate”

http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RoyerReply.pdf

 

[WhoWee]

look again

This 2000 year temperature chart is interesting - but is the measuring technique valid?
http://www.drroyspencer.com/global-warming-background-articles/2000-years-of-global-temperatures/

 

[ViewsofMars]

I found this to be interesting.

NASA - Global Climate Change - Uncertainties - Unresolved questions about Earth's climate
[snip]
Extreme Ultraviolet Imaging Telescope (EIT) image of the sun with a huge, handle-shaped prominence, taken in 1999. While there is no evidence of a change trend in solar output over the past half century, long-term changes in solar output are not well-understood.

[snip]

1. Solar Irradiance. The sun has a well-known eleven-year irradiance cycle that produces a .08% variation in output.1 Solar irradiance has been measured by satellite daily since the late 1970s, and this known solar cycle is incorporated into climate models. There is some evidence from proxy measurements-sunspot counts going back centuries, measurements from ancient trees, and others-that solar output varies over longer periods of time, too. While there is currently no evidence of a trend in solar output over the past half century, because there are no direct observations of solar output prior to the 1970s, climate scientists do not have much confidence that they understand longer-term solar changes. A number of U.S. and international spacecraft study the sun.

[snip]
http://climate.nasa.gov/uncertainties/

 

[sylas]

This 2000 year temperature chart is interesting - but is the measuring technique valid?
http://www.drroyspencer.com/global-warming-background-articles/2000-years-of-global-temperatures/

This thread is full of sloppy writing and bad referencing, by a number of contributors. People -- it is worth taking five minutes to give a clear reference, and it really helps. A URL needs some additional text describing what you link to. We should not have to click on a link to find out what is being linked. I like to use a conventional citation, with title, author, date and journal.

Andre's link you quote is to a google search for heavens sake! With no comment but "look again". This is completely unhelpful. A lot of others in the thread are nearly as bad.

Your url is not a valid reference for the forum. It is a personal site for Roy Spencer, who is a climate scientist; but a real oddity in several ways -- not just climate. That is, of course, ad hominem. If you want to use his peer reviewed research (which is mostly reasonable at least to the extent of being worthy of consideration; which is what peer review is intended to check) then we can consider it on its own merits. But his web page is not a suitable reference.

To avoid wasting time on nonsense, or on sorting out what is nonsense and what isn't; a basic forum requirement is that we use material which has at least passed this first hurdle of scientific peer review.

It's not at all clear what 2000 year temperature chart you mean... but according to the strict meaning of "valid", there's no such thing as a "valid" chart for 2000 years. All such charts are estimates, and subject to errors and uncertainties. Some, however, are much better than others. There is now an extensive body of peer reviewed research, using many different proxies and methods which give a roughly similar picture for the last 2000 years. These results are not all identical, and though they have succeeded in giving us a useful and scientifically well founded insight into the past, they are not strictly "valid" in the proper sense of the word. I don't see much of that work being described here.

There is a diagram in the link you provide... but that is still unsuitable for the forum! It is a temperature reconstruction that is published, but in a highly dubious journal (Energy and Environment) that does not have proper scientific peer review.

Energy and Environment doesn't show up in the recognized ranking systems and impact factors for scientific publications, anymore than OMNI or Readers Digest. The founder and main editor has a background in geography, politics and policy – not science. This magazine has become a clearing house for easy publication of low grade material that can't get into a real science journal. It has a superficial appearance of a real science journal, and is widely cited in blogs, pundits, second rate congressional submissions, etc, etc… but it has very little circulation in university libraries. It has been specifically identified by form mentors as an invalid reference. See [post=2142377]msg #6[/post] by Monique in the thread "Sources and Sinks of CO2" (now locked).

The particular reconstruction illustrated in your link is much less valid than what you will find in the legitimate scientific literature. You can find its errors explained online by working scientific experts, but not in the scientific literature. Why would they bother?

As a quick aside: Saul's material is more interesting and valid for consideration. It HAS been considered and problems with Shaviv's hypothesis have been properly identified and discussed as part of normal scientific debate in the proper channels.

Felicitations -- sylas

 

[Xnn]

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-ts.pdf

See page 30 to 31:

The estimated direct radiative forcing due to
changes in the solar output since 1750 is +0.12 [+0.06 to
+0.3] W m–2, which is less than half of the estimate
given in the TAR, with a low level of scientifi c
understanding. The reduced radiative forcing estimate
comes from a re-evaluation of the long-term change in
solar irradiance since 1610 (the Maunder Minimum)
based upon: a new reconstruction using a model of solar
magnetic flux variations that does not invoke geomagnetic,
cosmogenic or stellar proxies; improved understanding of
recent solar variations and their relationship to physical
processes; and re-evaluation of the variations of Sunlike
stars. While this leads to an elevation in the level
of scientific understanding from very low in the TAR
to low in this assessment, uncertainties remain large
because of the lack of direct observations and incomplete
understanding of solar variability mechanisms over long
time scales. {2.7, 6.6}

Empirical associations have been reported
between solar-modulated cosmic ray ionization of the
atmosphere and global average low-level cloud cover
but evidence for a systematic indirect solar effect
remains ambiguous. It has been suggested that galactic
cosmic rays with sufficient energy to reach the troposphere
could alter the population of cloud condensation nuclei
and hence microphysical cloud properties (droplet
number and concentration), inducing changes in cloud
processes analogous to the indirect cloud albedo effect
of tropospheric aerosols and thus causing an indirect
solar forcing of climate. Studies have probed various
correlations with clouds in particular regions or using
limited cloud types or limited time periods; however, the
cosmic ray time series does not appear to correspond to
global total cloud cover after 1991 or to global low-level
cloud cover after 1994. Together with the lack of a proven
physical mechanism and the plausibility of other causal
factors affecting changes in cloud cover, this makes the
association between galactic cosmic ray-induced changes
in aerosol and cloud formation controversial. {2.7}

 

[Saul]

http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-ts.pdf

See page 30 to 31:

Xnn,

The IPCC authors and the RealClimate authors appear to have not read the Palle or Tinsley papers on electroscavenging. This is only one of a set of papers.

As noted in this paper, depending on the sensitivity assumed for the planet's response to forcing due to a change in planetary cloud cover by both increased GCR and by solar wind bursts that remove ions via the process of electroscavenging, solar changes to cloud cover can account for 50% to 75% of the 20th century warming.

Now as the IPCC models have no solar modulation of planetary cloud cover, there is obviously a fundamental problem in the base GCM. Understanding what the fundamental error is and following the process of its discovery will be interesting.

http://www.arm.ac.uk/preprints/433.pdf

The possible connection between ionization in the atmosphere by cosmic rays and low level clouds by E. Palle, C.J. Butler, K. O’Brien

We use a simple model to calculate the climatic impact should the correlation be confirmed. We show that, under the most favorable conditions, a reduction in low cloud cover since the late 19th century, combined with the direct forcing by solar irradiance can explain a significant part of the global warming over the past century, but not all. However, this computation assumes that there is no feedback or changes in cloud at other levels.

As evidence for a cloud—cosmic ray connection has emerged, interest has risen in the various physical mechanisms whereby ionization by cosmic rays could influence cloud formation. In parallel with the analysis of observational data by Svensmark and Friis-Christensen (1997), Marsh and Svensmark (2000) and Palle´ and Butler (2000), others, including Tinsley (1996), Yu (2002) and Bazilevskaya et al. (2000), have developed the physical understanding of how ionization by cosmic rays may influence the formation of clouds. Two processes that have recently received attention by Tinsley and Yu (2003) are the IMN process and the electroscavenging process.

The second process, considered by Tinsley and Yu (2003), namely electroscavenging, depends on the action of the global electrical circuit (see review by Rycroft et al. (2000)). The transport of charge by rapidly rising convective currents in the tropics and over continental land masses leads to a 200 kV positive charge of the ionosphere compared to Earth.

 

[sylas]

General note: please limit the size of images. Very large images don't fit on the page and break the normal sizing of posts.

The IPCC authors and the RealClimate authors appear to have not read the Palle or Tinsley papers on electroscavenging. This is only one of a set of papers.

Realclimate authors are certainly aware of the electroscavenging hypothesis, and have mentioned it a couple of times, with reference to Palle and to Tinsley. But realclimate is not a valid source for the forum. It is, however, usually well referenced and you can use it as a way to identify possiblity relevant primary literature, which is okay for use in PF. The IPCC 4AR does describe this briefly but indirectly, with reference to other articles. The magnitude of the effect is still mostly hypothetical, and not well established as a significant factor.

It's worth emphasizing something about publication in scientific literature. It does NOT mean that the research therein has been found to be correct. It means it has been found to be worthy of consideration.

I'm thinking of putting together a better review of the relevant research; point and counter point, with a summary of claims and counter claims. By and large, the GCR linkage is still being argued, but has more problems than success. It may have a role in some cases. There's some indication of that, but the case is incomplete at best. The case for a role in the strong warming since the latter half of the twentieth century is weak at best. The electro-scavenging notion is a hypothesis for a possible way to get an effect, and not well established as a major factor as yet.

It's legitimate research for an unusual idea and the electroscavenging hypothesis is an open question; neither confirmed nor refuted, and with the extent of the linkage between GCR and the proposed electroscavenging process also unclear.

 

[Xnn]

Saul;

Notice:

Studies have probed various
correlations with clouds in particular regions or using
limited cloud types or limited time periods; however, the
cosmic ray time series does not appear to correspond to
global total cloud cover after 1991 or to global low-level
cloud cover after 1994.

It's not enough to simply show that cosmic rays are going up or down.
Cosmic rays impart very little energy to the earth.
Since the proposed mechanism is that they somehow alter cloud cover,
then one ought to be able to find multiple peer reviewed
articles in reputable journals that show this on a global level.
The problem with limiting studies to particular region is
that it smacks of cherry picking.

We know that changes in total solar radiance has a small
effect, but by my calculations it's equivalent to about 3-5 years
of changes in CO2 levels. Global warming is expected to continue
at about 0.015C/year with significant variations due to El Nino an La Nina.
Long term, once the oceans stop absorbing 90% of the energy, we will
experience even greater warming and CO2 levels are expected to accelerate
since the oceans won't be absorbing CO2 either.

 

[Saul]

Saul;

Notice:

It's not enough to simply show that cosmic rays are going up or down. Cosmic rays impart very little energy to the earth. Since the proposed mechanism is that they somehow alter cloud cover, then one ought to be able to find multiple peer reviewed articles in reputable journals that show this on a global level. The problem with limiting studies to particular region is that it smacks of cherry picking.

Xnn,

The Palle paper looked at planetary cloud cover for the entire planet.

You and the writers at Real Climate talk only about higher or low GCR. Actually you only talk about TSI. The GCM do not model planetary cloud cover. The IPCC reports states that modeling planetary cloud cover is the largest uncertainty in the AWG hypothesis and the GCM.

Modulation of planetary cloud cover is how solar changes and large changes to the geomagnetic field intensity cause the planet to warm and to cool.

You do not understand electroscavenging. Solar wind bursts remove cloud forming ions. That process is called electroscavenging. If GCR is high, for example at the end of the solar cycle, and there are solar wind bursts then the solar wind bursts remove the ions and there is less clouds not more clouds.

The solar wind bursts have increased by a factor of 4 at the end of the 20th century.

I see articles in Real Climate claiming the sun does not effect planetary temperature that talk about sunspot number or GCR which state that planetary temperature is not correlated with GCR. The debating technique is to create an incorrect strawman and then disprove the incorrect strawman hypothesis.

Svensmark's and Marshall's actual data shows planetary temperature is highly correlated with GCR up until around 1996 at which time there is a massive increase in the number of solar wind bursts. From 1996 on there is a reduction in planetary cloud cover particular over the tropics which results in a calculated increase in planetary forcing of 2.5 watts/m^2.

You and those writing at Real Climate appear to not understand the significance of that statement. Solar wind bursts are starting to abate. GCR is 19% higher than any period measured in the last 50 years. The planet is about to abruptly cool.

Based on the AWG hypothesis the planet cannot abruptly cool. The 20th century warming is asserted to have been due to the 30% increase in CO2, rather than due to an decrease in planetary clouds due to electroscavenging.

The GCM models assert that CO2 has caused an increase in forcing of 2.7 watts/m^2. That cannot be correct if the planet abruptly cools. If the planetary temperatures abruptly cools there must be something fundamental incorrect with GCM and the CO2 hypothesis. The CO2 hypothesis has CO2 increasing planetary temperature 24 hours a day, seven days a week. The CO2 mechanism is logarithmic. The first 30% increase in CO2 causes 73% of the temperature increase which does not match observations.

I can make that statement as abrupt cooling has happened before and there are concurrent cosmogenic isotope changes that are concurrent with the abrupt climate changes. There is paleoclimatic data that supports the mechanism. There is 20th Century data that supports the mechanism.

This paper shows the 20th century planetary changes are highly correlated with the geomagnetic index Ak which changes in response to solar wind bursts.http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf

Once again about global warming and solar activity K. Georgieva, C. Bianchi, and B. Kirov

Figure 2 demonstrates that the speed of the solar wind originating from CHs is much higher than of the solar wind associated with (Coronal mass ejections) CMEs and MCs. The yearly averaged speed of solar wind from CHs and MCs are comparable around sunspot maximum, and higher than the speed of CMEs, and everywhere outside sunspot maximum the fastest solar wind originates from CHs (Figure 3). Similarly, the average geo-effectiveness of solar wind from CHs is highest outside sunspot maximum (Figure 4) while around sunspot maximum the most geo-effective solar driver are MCs.

We show that the index commonly used for quantifying long-term changes in solar activity, the sunspot number, accounts for only one part of solar activity and using this index leads to the underestimation of the role of solar activity in the global warming in the recent decades. A more suitable index is the geomagnetic activity which reflects all solar activity, and it is highly correlated to global temperature variations in the whole period for which we have data.

In Figure 6 the long-term variations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataja 2003). The correlation between the two quantities is 0.85 with p<0.01 for the whole period studied.It could therefore be concluded that both the decreasing correlation between sunspot number and geomagnetic activity, and the deviation of the global temperature long-term trend from solar activity as expressed by sunspot index are due to the increased number of high-speed streams of solar wind on the declining phase and in the minimum of sunspot cycle in the last decades.

 

[sylas]

Based on the AWG hypothesis the planet cannot abruptly cool. The 20th century warming is asserted to have been due to the 30% increase in CO2, rather than due to an decrease in planetary clouds due to electroscavenging.

The GCM models assert that CO2 has caused an increase in forcing of 2.7 watts/m^2. That cannot be correct if the planet abruptly cools. If the planetary temperatures abruptly cools there must be something fundamental incorrect with GCM and the CO2 hypothesis. The CO2 hypothesis has CO2 increasing planetary temperature 24 hours a day, seven days a week. The CO2 mechanism is logarithmic. The first 30% increase in CO2 causes 73% of the temperature increase which does not match observations.

You pack a large number of basic errors into a small space.

It is not GCM models that give the forcing for CO₂. The forcing is determined by basic radiative and thermodynamic physics, entirely independent of the models. This is known to about 10% accuracy and with very high confidence. It's basic physics. I gave the references in thread [thread=307685]Estimating the impact of CO2 on global mean temperature[/thread]. See especially Myhre et al., (1998).

You've got the forcing wrong in any case. The CO₂ forcing is about 1.7 W/m² since pre-industrial times. You appear to be thinking of the total greenhouse forcing, including a whole pile of other gases, which is about 2.63. The other main contributors are CH₄, N₂O, and halocarbons. Numbers can be found in the IPCC 4th AR, for the forcing from 1750-2005, in table 2.12 on page 204. Note that there are also a whole pile of other non-greenhouse forcings as well, which are generally much less well known.

The CO₂ forcing is used by skeptics and supporters of AGW alike. I am speaking here of scientifically literate skeptics of the AGW hypothesis.

The major uncertainty is not the forcing, but the response, or climate sensitivity -- also discussed in that thread. There is also uncertainty about OTHER forcings, especially those relating to cloud. The role of GCR in this is still speculative and not at all confirmed. It is not possible to calculate a GCR forcing from basic physics at this point, and measurements are ambiguous. The notion of electroscavenging has some good support, but it is also not well understood as yet -- and it is not exclusively about GCR in any case. The effect of GCR on electroscavenging processes is not well confirmed. Some time I'd like to put together a proper literature review on this interesting proposal.

As has been pointed out to you before, your 24 hours a day 7 days a week remark is a strawman. AGW does not rule out the normal natural variation which proceeds all the time, nor does it rule out all kinds of forcings beyond CO2 and greenhouse effects. Indeed, "anthropogenic" covers quite a range of different forcings. You repeated invocation of this "continuity" stawman is absurd. You are inventing it out of the whole cloth. You'll never find anything so silly in the scientific literature.

Your basic algebra is also incorrect. An increase from 280 to 380 ppm would be log₂(380/280) = 0.44 of a doubling. The first 30% of this rise would be from 280 to 310 ppm, which is log₂(310/280) = 0.15 of a doubling... or about 33.3% of the forcing. Not 73%.

Your stuff on GCR is interesting, though you are not presenting any of the literature that looks at the problems with this hypothesis. You should.

Your claims with respect to anthropogenic forcings and greenhouse forcings are completely incorrect.

Cheers -- sylas

 

[Xnn]

Saul;

Here's the conclusion from the Palle paper:

The correlation between annual mean low cloud and
the ionization level at 2 km altitude exceeds the 99%
significance level over mid-latitude oceans and globally
over the period 1983–1994. However, globally, it
drops to non-significant values if the full available
cloud dataset (1983–2001) is taken into account
although some data adjustment such as detrending
can restore the correlation significance to 99.5% or
greater. Nonetheless, the correlation is significant over
several large areas of the earth.

In other words, if they focus on just part of the data, they can find a correlation.
But when they include more data, the correlation falls apart.
That is just cherry picking.

Looking at figure 8 in their report, it becomes even more apparent
just how much the correlation has fallen apart since the mid 80's.
They predicted flat to falling temperatures since then, while
the globe and oceans have continued to warm.

and then there is this statement...

There is relatively good agreement between the observed
anomaly and the combined curves for the period
1870–1910, but increasing divergence from 1910 onward.
By the 1990s, the difference is of the order one
third to one half of the global warming since the late
19th century.

Got that?

Good agreement from 1870 to 1910; progressively worse since then.
Even a stopped clock is correct twice a day.

 

[Xnn]

I should probably add that while greenhouse gases have been on a steady rise for a long time, it's only been the last 60 years that they have clearly become dominate.

 

[Skyhunter]

Saul,

For a little better understanding of the problems with Shaviv 2003 I suggest http://es.ucsc.edu/~jzachos/pubs/Rahmstorf_etal_2004.pdf"

http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmReplyReply.pdf" to Rahmstorf's critique does not address the fundamental errors. They simply argue that they can employ their statistical method to low resolution proxies and arrive at a robust conclusion.

The GCR/cloud hypothesis is still highly speculative. If there is a connection, and I believe there is, it's effect is as yet undetermined. Since most of the warming is already accounted for by known physical processes, the amount of forcing, if any, will be small compared to anthropogenic forcings.

 

[Saul]

I note Rahmstorf did not reply to Shaviv's reply to Rahmstorf et al criticism. The RealClimate blog comment by Rahmstorf also did not respond to Shaviv's comments. Shaviv's analysis shows there is correlation of all of the past ice epochs with high GCR as the solar system passed through the galaxy's spiral arms. There is also a mechanism by which high GCR increases planetary cloud cover and cools the planet.

This is only the comments of the analysis of the iron meteoroids and passage of the the solar system through the galactic arms. The RealClimate blog stated the solar system could not have passed through the galaxy's spiral arms. I provided a link to an independent Astronomical paper that supported Shaviv's analysis.

http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmstorfDebate.pdf

http://www.phys.huji.ac.il/~shaviv/ClimateDebate/RahmReply/RahmReply.htmlDetailed Response to “Cosmic Rays, Carbon Dioxide and Climate” by Rahmstorf et al.

It is certainly true that the complete meteoritic data includes clusters of meteorites of the same type, and that such clusters are most likely the result of a single parent body breaking up into many small pieces, but this is totally irrelevant. As detailed in Shaviv [2002] and Shaviv [2003], in order to neutralize this effect, a modified meteoritic data set is generated (using 80 K-dated Iron Meteorites) where clusters of meteorites of the same Iron group classification are replaced with one having an average age. Thus, the clustering can either be because of a variable CRF, or, simply because parent bodies tend to break up more often periodically. However, it is not likely that single bodies generated each of the clusters, since each cluster is now comprised of meteorites that are all of different Iron group classification. ….

Irrespective, even if the CRF were constant, and even if the origin of the clusters were single heterogeneous asteroids, each giving rise to a heterogeneous cluster, we still find that the periodic pattern in the “celestial” signal correlates with the pattern in the terrestrial one! Moreover, independent evidence in the Iron meteorite data, based on comparison of different exposure dating methods, clearly shows that the CRF over the past 10 Ma must have been 30% higher than was the average over the past 1000 Ma [Lavielle et al. 1999]. If it was variable recently, it is unlikely that it was constant before. Plus, the astronomical understanding of the origin and diffusion of cosmic rays in the galaxy predicts that the CRF should be variable. It is therefore not surprising that it is observed, as predicted, in the meteoritic data. The periodicity in the exposure ages of meteorites, which includes now also exposure ages based on 36Cl, is described in figure 1. As clearly evident from the figure, the meteorites cluster periodically. This is highly unlikely to be a random fluke.

Last, a periodicity in CRF is predicted also by the current astronomical theory. Summing up, we did not use only 20 meteorites to reconstruct the CRF. We used all K-dated meteorites (80 reduced to 50 “heterogeneous” ones) to obtain the most accurate signal possible (147 ± 10 Ma) in order to compare it with climate variations. The fact that just the subset of meteorites with ages less than 520 Ma reveals the same clustering (albeit with reduced statistics), implies that it is valid to assume that the periodic signal obtained for 0-1000 Ma is valid also for just the 0-520 Ma period.

Another problem of the CRF reconstruction is the presumption of “periodicity” of the clusters. The time spans between the clusters’ gaps, which correspond to high CRF in their theory, are roughly 90, 90, 140, 130, 190, 140 Myr (Fig. 4 of [Shaviv, 2003]). The claim that these data support a periodicity of 143 ± 10 Myr seems not obvious. See figure 1, which vividly demonstrates the periodicity.

Together with the 36Cl exposure dating, the fit is now even better, with a periodicity of 147 ± 6 Ma. The passage through the four galactic arms should be a regular process; the high variability of the age gaps is not addressed. If Rahmstorf et al. would have taken the time to study Shaviv [2003], which they obviously did not, they would have found Table 2 in Shaviv [2003] which addresses the theoretical uncertainty in the prediction of the spiral arm passages and the uncertainly in the paleoclimatic data determining the peak of the cold periods. In addition, there is an intrinsic measurement error when estimating the difference between two adjacent spiral arm crossings when using the meteiritic data. If one looks at the bottom panel of fig 4 in Shaviv [2003], where the clusters are seen by eye, one can measure by hand that the differences between the mid-points of the clusters, these are: 80, 115, 155, 150, 150, 135 Ma. The width of each cluster is about 70 Ma. Therefore, the error in the determination of a single difference is about (70 Ma/2)p2 = 50 Ma. Compounded to that, one has to add the natural ‘jitter’ in the spiral arm passage (due to the solar system’s epicyclic motion, orbital parameter diffusion and internal structure of the spiral arms, [Shaviv, 2003]). Thus, one finds that the differences are all consistent with their average.

The CRF model is based on the assumption that cosmic ray density should be concentrated in the Galactic spiral arms, with a time lag of peak CRF of about 15 Myr behind the spiral arm passage. CRF is computed by a simple diffusion model with several free parameters. These parameters are constrained by ‘observational constraints’, including the meteorite data. These constraints are very weak; the crucial cosmic ray diffusion coefficient can only be constrained to within two orders of magnitude. Whether the Astronomical data form weak constraints or not is a vague definition. The astronomical constraints alone do indicate that the CRF should have been variable, that the period should be 135 ± 25 Ma, that the CRF should peak at 31 ± 8 Ma after the spiral arm passage, that the last passage was at about 50 Ma before present, that the CRF had amplitude variations between a factor of 2 to 10. Clearly they are not trivial. Thus, perhaps with the exception of the total amplitude of the variations, the astronomical data does place meaningful constraints on the CRF variability. Mreover, even the best-fit CRF model does not fit the meteorite data well. For the time span analysed in SV03, the cluster gaps are located near 100 Myr, 190 Myr, 280 Myr and 420 Myr BP (Fig. 4 of [Shaviv, 2003]); they are supposed to coincide with CRF maxima which the best fit’ model locates at about 30 Myr, 170 Myr, 360 Myr and 470 Myr BP. This is hardly a good agreement, with an r.m.s. deviation of 60 Myr. Agreement of the three CRF minima (at 80 Myr, 250 Myr, 420 Myr BP) with the age clusters (at 140 Myr, 250 Myr, 360 Myr BP) is hardly better, with two of the three clusters off by almost half a period.

A careful study of the Shaviv [2003] paper would have revealed that indeed the meteoritic ages are supposed to cluster around epochs with a lower CRF. However, the “time” axis is the K exposure age and not the real age. In other words, Rahmstorf et al. failed to understand that they were comparing K-ages of the clusters to the real ages of geologically warm periods. Since there could be a distortion of up to half a period (depending on the phase of the current epoch) between the K-age and a real age, it is wrong to compare the exposure ages directly to the occurrence of ice-age epochs or to the reconstructed CRF in “real time”. This is the reason why the histogram of exposure ages was predicted based on the geological periodicity and compared with the data (i.e., all done in K-CRF exposure time), in which case all the clusters’ Kage peak exactly as predicted, within the measurement (i.e., dating) and physical (e.g., epicyclic motion) errors. Moreover, the largest discrepancy is with the first cluster, but this arises because Voshage & Feldman [1979] excluded from their data base young meteorites, because their method did not date them well enough. Once more meteorites are included (using the 36Cl data) there is no statistically significant discrepancy between any of the clusters and their predicted location.