All things Solar

[LakeEffectKing]

Convection has no effect on albedo other than an increase in cloud propagation or density. If you're arguing that increased cloudiness over the tropics limits solar radiation, you're arguing against yourself. Convection increases as the temperature delta increases, and if increased cloudiness lowers tropical temperatures then convection will decrease unless the polar zones decrease in temperature by an equal or greater amount.

I can't imagine why you are arguing this. I recall you stating you understood that greenhouse gasses were responsible for the preponderance of the global warming.

Terry

Didn't know I was arguing....thought I was answering a query of yours, and was sharing my thoughts with you in an attempt to have a more civilized exchange than those in the past.....I guess I failed. Am I wrong?

[PhillipS]

Wrong on all counts.

Whether there has been an increase or decrease in TSI over the last 50 years is still currently open for debate.

There has been a decrease in Cosmic Rays, and an increase in all other solar variables, other than TSI.

This figure from Dorman 2012 above combines the global temperature anomalies to the Cosmic Ray Flux (CRF) from 1937-1994. There is a very good correspondance between the two variables, suggesting that Cosmic Rays (modulated by solar activity) play a large and dominant role in current climate change.

The SSN is a poor indicator to use for quantifying the solar impact, since it does not include all of the aspects of the geomagnetic activity from the sun.

Using the geomagnetic AA Index instead of the SSN gives a better approximation of solar activity than the SSN, since it accounts for all of the sun's magnetic activity changes.

When you do so, the Global temperature is highly correlated (r^2=0.85) to temperature changes.

"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."

Urbanization can primarily be responsible (as well as warming oceans) for the negative trend in the DTR observed in most weather stations.

Fall et. al 2011 finds that in the CRN 5 weather stations, there is a significant decrease in the DTR range. Keep in mind that the CRN 5 stations are the worst quality stations, with many of them being impacted by urbanization.

The graph above shows the trends in the diurnal temperature range for each type of weather station. There is no statistically significant trend in the diurnal temperature range for the best quality stations, wheras in the urbanized stations there is a statistically significant decrease in the DTR. What does this mean? It means that urbanization could account for most or all of the decrease in the DTR for most of the weather stations, since the highest quality weather stations do not display a trend in the DTR.

This also means that CO2 is not the driver of climate change in the best quality weather stations, or else we still would have observed a statistically significant decrease in the DTR in these non-urbanized weather stations, since there is no urban effect to contaminate the trends in the DTR in the best quality weather stations.

Stratospheric Cooling is entirely consistent with the sun theory. Shall I explain why?

I don't have time right now for a full response but I'll try to do better later. Using the Dorman et al 2012 paper to support your position is a very weak reed to lean on. It has been soundly criticized for ignoring recent data. Indeed, the figure you posted from the paper cuts off data at 1990. Why would the authors leave off the last 22 years of data if it supported their hypothesis? Cherrypicking, perhaps?

Here's a plot of cosmic ray activity for the period 1950 - 2006 from the University of New Hampshire:

The cosmic ray activity seems to be pretty highly inversely correlated with sunspot activity, and pretty stable within the long-term max and min. No long-term trend as far as I can see.

I couldn't find a long-term Ak plot but I did find this definition:

The Ak(Hel) index measuring the geomagnetic activity was created by Nevanlinna and Ketola (1993). It has been adjusted with the aa index to form the longest uniform index of global geomagnetic activity, extending over the last 14

solar cycles

(Nevanlinna and Kataja, 1993).

While looking for a recent Ak or aa index plot I did come across a paper which may be relevant to this discussion. It's by Love et al 2011 entitled, Are secular correlations between sunspots, geomagnetic activity, and global temperature significant?

The abstract:

Recent studies have led to speculation that solar‐terrestrial interaction, measured by sunspot number and geomagnetic activity, has played an important role in global temperature change over the past century or so. We treat this possibility as an hypothesis for testing. We examine the statistical significance of cross‐correlations between sunspot number, geomagnetic activity, and global surface temperature for the years 1868–2008, solar cycles 11–23. The data contain substantial autocorrelation and nonstationarity, properties that are incompatible with standard measures of crosscorrelational significance, but which can be largely removed by averaging over solar cycles and first‐difference detrending. Treated data show an expected statisticallysignificant correlation between sunspot number and geomagnetic activity, Pearson p < 10−4, but correlations between global temperature and sunspot number (geomagnetic activity) are not significant, p = 0.9954, (p = 0.8171). In other words, straightforward analysis does not support widely‐cited suggestions that these data record a prominent role for solar‐terrestrial interaction in global climate change. With respect to the sunspot‐number, geomagnetic‐activity, and global‐temperature data, three alternative hypotheses remain difficult to reject: (1) the role of solar‐terrestrial interaction in recent climate change is contained wholly in long‐term trends and not in any shorter‐term secular variation, or, (2) an anthropogenic signal is hiding correlation between solar‐terrestrial variables and global temperature, or, (3) the null hypothesis, recent climate change has not been influenced by solar‐terrestrial interaction.

Citation: Love, J. J., K. Mursula, V. C. Tsai, and D. M. Perkins (2011), Are secular correlations between sunspots,

geomagnetic activity, and global temperature significant?, Geophys. Res. Lett., 38, L21703, doi:10.1029/2011GL049380.

(emphasis mine)

Check out figure 1 which shows long-term data for sunspots, aa index, and global temperatures. As you can see, in recent years they have been heading in opposite directions, solidly refuting the denialist meme "It's the Sun!". Dontcha hate it when a beautiful hypothesis gets brutally stomped on by reality?

[Snow_Miser]

I don't have time right now for a full response but I'll try to do better later. Using the Dorman et al 2012 paper to support your position is a very weak reed to lean on. It has been soundly criticized for ignoring recent data. Indeed, the figure you posted from the paper cuts off data at 1990. Why would the authors leave off the last 22 years of data if it supported their hypothesis? Cherrypicking, perhaps?

Here's a plot of cosmic ray activity for the period 1950 - 2006 from the University of New Hampshire:

The cosmic ray activity seems to be pretty highly inversely correlated with sunspot activity, and pretty stable within the long-term max and min. No long-term trend as far as I can see.

I couldn't find a long-term Ak plot but I did find this definition:

While looking for a recent Ak or aa index plot I did come across a paper which may be relevant to this discussion. It's by Love et al 2011 entitled, Are secular correlations between sunspots, geomagnetic activity, and global temperature significant?

The abstract:

Recent studies have led to speculation that solar‐terrestrial interaction, measured by sunspot number and geomagnetic activity, has played an important role in global temperature change over the past century or so. We treat this possibility as an hypothesis for testing. We examine the statistical significance of cross‐correlations between sunspot number, geomagnetic activity, and global surface temperature for the years 1868–2008, solar cycles 11–23. The data contain substantial autocorrelation and nonstationarity, properties that are incompatible with standard measures of crosscorrelational significance, but which can be largely removed by averaging over solar cycles and first‐difference detrending. Treated data show an expected statisticallysignificant correlation between sunspot number and geomagnetic activity, Pearson p < 10−4, but correlations between global temperature and sunspot number (geomagnetic activity) are not significant, p = 0.9954, (p = 0.8171). In other words, straightforward analysis does not support widely‐cited suggestions that these data record a prominent role for solar‐terrestrial interaction in global climate change. With respect to the sunspot‐number, geomagnetic‐activity, and global‐temperature data, three alternative hypotheses remain difficult to reject: (1) the role of solar‐terrestrial interaction in recent climate change is contained wholly in long‐term trends and not in any shorter‐term secular variation, or, (2) an anthropogenic signal is hiding correlation between solar‐terrestrial variables and global temperature, or, (3) the null hypothesis, recent climate change has not been influenced by solar‐terrestrial interaction.

Citation: Love, J. J., K. Mursula, V. C. Tsai, and D. M. Perkins (2011), Are secular correlations between sunspots,

geomagnetic activity, and global temperature significant?, Geophys. Res. Lett., 38, L21703, doi:10.1029/2011GL049380.

(emphasis mine)

Check out figure 1 which shows long-term data for sunspots, aa index, and global temperatures. As you can see, in recent years they have been heading in opposite directions, solidly refuting the denialist meme "It's the Sun!". Dontcha hate it when a beautiful hypothesis gets brutally stomped on by reality?

I'll debunk each of your claims one by one.

Your first claim is a widely debunked claim that all AGW advocates seem to post about on various forums.

I take it that the record LOW in GCRs in 1992 does not count as a decrease in GCRs, or the fact that the GCR cycle ending in 1992 featured the shortest GCR cycle on record, leading to the least amounts of the cumulative GCR Counts on record in that cycle during any cycle over the last 150 years?

Or the fact that there has been a long term decrease in GCRs over the last 150 years, as according to Carslaw et. al 2002? Once again, the record low occured in 1992, suggesting an increase in solar activity over the last 50 years.

You are aware that the graph in Dorman 2012 comes from Svensmark 2000, right? If you had opened up the paper and read that, you would have clearly seen that. The fact that GCRs can explain most to all of the warming up to 1994 is pretty telling, considering later, when the GCR Flux increased, temperatures started to flatline.

A long term trend in solar activity as found by Raspopov et. al and Mufti and Shah can easily cause all of the warming observed, since each study found that long term trends upward in solar activity leadto a profound response.

The Love et. al paper shows an AA increase until about 1996, when it starts to decline. Assuming a few year lag, this matches up pretty nicely with global temperatures.

I will leave you with a few more studies which point to a large influence of solar activity on climate change in recent decades.

Soon et. al 2011:

(From the abstract:)

The 20th century surface air temperature (SAT) records of China from various sources are analyzed using data which include the recently released Twentieth Century Reanalysis Project dataset. Two key features of the Chinese records are confirmed: (1) significant 1920s and 1940s warming in the temperature records, and (2) evidence for a persistent multidecadal modulation of the Chinese surface temperature records in co-variations with both incoming solar radiation at the top of the atmosphere as well as the modulated solar radiation reaching ground surface. New evidence is presented for this Sun–climate link for the instrumental record from 1880 to 2002. Additionally, two non-local physical aspects of solar radiation-induced modulation of the Chinese SAT record are documented and discussed.

Teleconnections that provide a persistent and systematic modulation of the temperature response of the Tibetan Plateau and/or the tropospheric air column above the Eurasian continent (e.g., 30°N–70°N; 0°–120°E) are described. These teleconnections may originate from the solar irradiance-Arctic–North Atlantic overturning circulation mechanism proposed by Soon (2009). Also considered is the modulation of large-scale land–sea thermal contrasts both in terms of meridional and zonal gradients between the subtropical western Pacific and mid-latitude North Pacific and the continental landmass of China. The Circum-global teleconnection (CGT) pattern of summer circulation of Ding and Wang (2005) provides a physical framework for study of the Sun–climate connection over East Asia. Our results highlight the importance of solar radiation reaching the ground and the concomitant importance of changes in atmospheric transparency or cloudiness or both in motivating a true physical explanation of any Sun–climate connection. We conclude that ground surface solar radiation is an important modulating factor for Chinese SAT changes on multidecadal to centennial timescales. Therefore, a comprehensive view of local and remote factors of climate change in China must take account of this as well as other natural and anthropogenic forcings.

Tinsley et. al 2009 find that the CRF (Cosmic Ray Forcing) is a likely climate driver, and find that it needs to be represented in the models, since it has a very important role in climate change.

Belov et. al 2005

A method of prediction of expected part of global climate change caused by cosmic ray (CR) by forecasting of galactic cosmic ray intensity time variation in near future based on solar activity data prediction and determined parameters of convection-diffusion and drift mechanisms is presented. This gave possibility to make prediction of expected part of global climate change, caused by long-term cosmic ray intensity variation. In this paper, we use the model of cosmic ray modulation in the Heliosphere, which considers a relation between long-term cosmic ray variations with parameters of the solar magnetic field. The later now can be predicted with good accuracy. By using this prediction, the expected cosmic ray variations in the near Earth space also can be estimated with a good accuracy. It is shown that there are two possibilities: (1) to predict cosmic ray intensity for 1–6 months by using a delay of long-term cosmic ray variations relatively to effects of the solar activity and (2) to predict cosmic ray intensity for the next solar cycle. For the second case, the prediction of the global solar magnetic field characteristics is crucial. For both cases, reliable long-term cosmic ray and solar activity data as well as solar magnetic field are necessary. For solar magnetic field, we used results of two magnetographs (from Stanford and Kitt Peak Observatories). The obtained forecasting of long-term cosmic ray intensity variation we use for estimation of the part of global climate change caused by cosmic ray intensity changing (influenced on global cloudiness covering).

Borie and Thoyaib 2006.

The abstract reads:

Data for geomagnetic activity index aa and solar sunspot number Rz for 1868-2004 were subjected to

correlation analysis with the global surface temperature (GST). The annual-means GT show that it had

two warming phases and one cooling period. Observations of the Earth's near-surface temperature

showed a global-mean temperature increase of approximately 1.1° C since 1877, occurred from 1887 to

1940 and from 1970 to the 1998. The temperature change over the past 35 years (1970-2004) is unlikely

to be entirely due to internal climate variability. Attribution of the warming early in the century has

proved more elusive. The correlation analysis between the variation of global temperature and both aa

geomagnetics and solar activity are +0.5 ± 0.05, for any lag or lead, indicating a significant role in such

variation. All graphs have illustrated strong correlations between the solar activity and geomagnetics

and surface global temperature. Our results do not, by any means, rule out the existence of important

links between solar activity and terrestrial climate. Our results displayed that the present changes in aa

geomagnetics may reflect partially some future changes in the global surface temperatures.

From the conclusions:

The excess of aa geomagnetics led to excess

solar energy which stored and accumulated for few future

years in the near-Earth system, leading to the global

temperature variability. The running coefficients for the

late years (1873-1930) displayed only negative

remarkable role of solar activity or/and aa geomagnetic in

global temperature change (Figure 5b). On contrast, the

aa index and the sunspot number played, direct or

indirect, a great role in global cooling temperature

throughout four decades from 1931 to 1970. During the

period 1971-1998, the correlation between Rz and

temperature persisted positively. So, the sensitivity of

global temperature to aa geomagnetics is significant and

may be real.

Blanter et. al 2008

Blanter et. al 2008 found that temperatures correlated remarkably well for all periods between the solar activity indicies and the observed temperatures for stations in Europe and the United States during the 20th Century. They used a finding from a previous study that the temperatures at weather stations correlated remarkably well if they were up to a 1000 km distance from each other. They also state in the abstract that these changes can "possibly" be extended onto a Global scale. Being that they found that solar activity can account for all temperature changes over the 20th Century, I reduced the range slightly from 100% to somwhere in the 90-100% range to account for the anthropogenic forcings.

http://www.pnas.org/...7/23/12433.full

Current global warming commonly is attributed to increased CO2 concentrations in the atmosphere (3). However, geophysical, archaeological, and historical evidence is consistent with warming and cooling periods during the Holocene as indicated by the solar-output model. The current warm period is thought to have not reached the level of warmth of the previous warm period (A.D. 800-1200), when the Vikings raised wheat and livestock in Greenland. Therefore, the magnitude of the modern temperature increase being caused solely by an increase in CO2 concentrations appears questionable. The contribution of solar-output variations to climate change may be significant.

http://rspa.royalsoc... ... /1221.full

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 h−1, which occur 87% of the time on average) compared with low cosmic ray flux, (i) the chance of an overcast day increases by (19±4) %, and (ii) the diffuse fraction increases by (2±0.3) %. 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.

[Snow_Miser]

How does that work? How can decreasing solar output coincide with increasing arctic warming ?

ghg forcing works with solar radiation. If the sun was the driver the warming would be methodical not abrupt during spring.

the ice and snow was at normal levels in March and April.

now they are at recorded lows.

Where is your evidence that solar output has decreased over the last 30 or so years?

http://www.fel.duke.edu/~scafetta/pdf/opinion0308.pdf

Scafetta and West 2008 adresses the uncertainty raised in the first paper. If a TSI curve that shows an upward trend from Solar Cycle 21 to 22 is used from the ACRIM TSI composite rather than the flat PMOD TSI composite, then a higher contribution from the sun would be needed. The authors find that up to 69% of the variances in temperatures can be explained by solar activity.

The image above from Scafetta and West 2008 shows the divergence between the PMOD and ACRIM TSI datasets, which makes attribution to past climate change even harder. The red curve is the ACRIM TSI composite, the blue curve is the PMOD TSI Composite, and the black curve and green line are the Global Temperature anomalies.

http://www.fel.duke.edu/~scafetta/pdf/2007JD008437.pdf

The ACRIM verses PMOD controversy continues in Scafetta and West 2007. 50% or more of temperatures can be attributed to the solar forcing, depending if the ACRIM TSI composite is used or not. This further adds on to resolving the uncertainty between the PMOD and ACRIM datasets during the ACRIM Gap.

The graph above from Scafetta and West 2007 shows the excellent correlation between solar activity and temperatures. It also shows that a large portion of the warming can be attributed to solar activity. Over the last 30 years, a significant portion of the warming can be attributed to solar activity if the ACRIM TSI composite is used.

Solar Cycle 22 ran more solar flux than Solar Cycle 21 did, which is an indicator of a rise in solar activity. Note the tremendous increase in solar activity over the entire 20th Century.

Solar Cycle 22 was also shorter than Solar Cycle 21, and the shortest cycle in the entire 20th Century, and the shortest solar cycle since 1833 (the shorter the solar cycle, the more active the sun.) It should be noted though, that according to Wiki, Solar Cycle 22 was even shorter than Solar Cycle 8.



GCRs reached an all time record low in 1992, which gives credence to the ACRIM dataset showing increasing TSI (an indicative of increasing solar activity) over the last 30 years.

Arctic Amplification happens with it starting in the summer. Increased solar radiation creates the ice to melt.. There is now more open water exposed than before, so more of the solar radiation is absorbed by the ocean, and the ocean is now a higher temperature than before. During the wintertime, when the surface air temperature becomes significantly cooler than the ocean temperature, a great deal of heat is lost from the oceans to the atmosphere, so the atmosphere warms the fastest during the wintertime. It is the 2nd Law of Thermodynamics at work.

What is your supporting evidence that,

If the sun was the driver the warming would be methodical not abrupt during spring.

Or is this mere speculation?

[Snow_Miser]

To Terry:

Arctic Amplification happens with it starting in the summer. Increased solar radiation creates the ice to melt.. There is now more open water exposed than before, so more of the solar radiation is absorbed by the ocean, and the ocean is now a higher temperature than before. During the wintertime, when the surface air temperature becomes significantly cooler than the ocean temperature, a great deal of heat is lost from the oceans to the atmosphere, so the atmosphere warms the fastest during the wintertime. It is the 2nd Law of Thermodynamics at work.

This was the same response as I gave to Friv.

[LakeEffectKing]

Soon et. al 2011:

Well, it was nice playing with you....kiss your credibility goodbye....the mention of Soon will get you:

[ben4vols]

A quick question for Snowlover or anyone else who might want to take a stab at this. My understanding of reading Svensmark's theory is that our solar system is orbiting around the center of our Galaxy which takes about 230 million years to make a full cycle. During the trek we will be going in and out of the spiral arms of the galaxy where more GCRs exist. It seems odd to me, those that point to 60 years of GCR data and say the Svensmark theory doesn't work since 60 years out of 230 million is such a small number. Looking at the last 60 years of GCR data it looks like there is little variation but would this not be expected since it would, in relation, be like only going .0165" in a mile long journey. In other words we have barely moved over the last 60 years.

For the record I neither accept nor deny Svensmark's theory.

[cmc0605]

It's unfortunate that the science of cosmic ray impacts on cloud cover has become somewhat of a pseudo-astrology fallback for some skeptics. This is partly because there aren't good theoretical relationships that have been developed, the arguments get technical quickly, and there are a number of conflicting peer-reviewed publications on the matter.

There are also real correlations that do exist in the literature between GCR and low-level cloud, although it is often the case that the statistics are not quite robust to the time frame used, to certain cloud types, or may develop from changes in atmospheric heating and circulation, rather than an impact of cosmic rays. I think a fair summary is that ionization from cosmic rays may enhance aerosol nucleation in the free troposphere, though the ionization is most likely too weak to influence global-scale cloud cover and influence climate in any significant way. (Note that the upcoming AR5 report has detailed sections on 1) various studies that have attempted to establish corrections between cosmic rays and some climate variable, 2) a discussion of the proposed physical mechanisms linking cosmic rays to climate).

All of this confusion makes for a good recipe in making things up, and selecting the bits and pieces of literature which suit people's pre-conceived notions. It's too bad because it has potential to be an interesting field, and in fact has been well studied in laboratory and field campaigns (which get far less attention than the few "loud" voices). but the serious science on the matter has not provided much support for a robust relationship between climate and cosmic rays; indeed, most non-TSI related solar mechanisms are very subtle, often more dynamical than radiative in nature, and may be at best a second or third order "fine-tuning" effect for climate change in general.

As happens in the unforgiving world of science, people like Svensmark, Shaviv, Scafetta, Soon are no longer taken seriously due to some rather odd publications with some very odd analysis on these topics (citation counts, specifically ones in legitimate journals, may be a good proxy for their merit). It is interesting to see people with a real interest in climate revisit the subject and discuss these papers, but the fact remains that the sensitivity of CCN concentrations to the nucleation caused by GCR is not well established, and large-scale relationships between clouds and cosmic rays has not been established with high confidence. The people banking on such theories might convince themselves or some people on the internet of their legitimacy, but to actually advance as a scientific idea, it should be able to have some explanatory and predictive power that is borne out in observations, is robust to specific choices used in a study, and stand the test of scrutiny over time. This has not been done yet, nor has anyone quantified the radiative forcing of such changes (aside from the obvious logical fallacy in that finding a new forcing mechanism does not "replace" existing, well-understood ones).

[cmc0605]

Terry,

I wouldn't try to find much connection between the spatial distribution of the radiative forcing and the spatial distribution of the temperature response. In fact, even though CO2 is well-mixed in the atmosphere, its top of the atmosphere radiative forcing is maximum in the tropics (see e.g., Figure 2 in http://www.springerl...77gr5lx8421105/) and which you can verify in looking at the modeled spatial forcing distribution at http://data.giss.nas...y/Fa.1.06.html.

That paper also describes mechanisms of polar amplification, which can result even without the ice-albedo feedback, and must arise from changes in poleward heat fluxes, as well as the fact that the enhanced longwave radiation to space suppresses warming less so at high latitudes than at low latitudes. (Even the water vapor feedback is maximum in the tropics, so whatever mechanism is at play must overwhelm this as well). However, polar amplification seems to be a rather robust property of the climate system (seen in Eocene or Cretaceous warm intervals, at the LGM, etc). You also see this in solar simulations, e.g., http://data.giss.nas...Rc_ij.3.06.html

(P.S. I suspect there is still room for this as a research question, and a number of "new" end up being proposed to explain amplification and equable climates, such as dynamics (http://journals.amet...ournalCode=clim) or cloud responses to biological feedbacks (http://www.sciencema.../5873/195.short) but because of the robust character of polar amplification (in observations, and in multiple levels of model complexity) I strongly suspect it is not intimately tied to physics that is unique to the current climate or to the fine structure of how the radiative forcing is applied. As an aside, I've also seen it mentioned in many casual forums that the seasonal summer-winter or equator-to-pole temperature structure provides a robust fingerprint to either solar or greenhouse forcing, but I have not found any justification for this in the literature, and think most of that argument collapses in light of actual evidence. The fingerprint stuff also breaks down a bit for the diurnal structure in warming too, which has a lot to do with aerosols and clouds instead. But I'm a bit biased in all this; my interest is in the theory of climate, and I don't get too excited over mechanisms that operate only over a very narrow range of possible parameter-space).

[Snow_Miser]

It's unfortunate that the science of cosmic ray impacts on cloud cover has become somewhat of a pseudo-astrology fallback for some skeptics. This is partly because there aren't good theoretical relationships that have been developed, the arguments get technical quickly, and there are a number of conflicting peer-reviewed publications on the matter.

There are also real correlations that do exist in the literature between GCR and low-level cloud, although it is often the case that the statistics are not quite robust to the time frame used, to certain cloud types, or may develop from changes in atmospheric heating and circulation, rather than an impact of cosmic rays. I think a fair summary is that ionization from cosmic rays may enhance aerosol nucleation in the free troposphere, though the ionization is most likely too weak to influence global-scale cloud cover and influence climate in any significant way. (Note that the upcoming AR5 report has detailed sections on 1) various studies that have attempted to establish corrections between cosmic rays and some climate variable, 2) a discussion of the proposed physical mechanisms linking cosmic rays to climate).

All of this confusion makes for a good recipe in making things up, and selecting the bits and pieces of literature which suit people's pre-conceived notions. It's too bad because it has potential to be an interesting field, and in fact has been well studied in laboratory and field campaigns (which get far less attention than the few "loud" voices). but the serious science on the matter has not provided much support for a robust relationship between climate and cosmic rays; indeed, most non-TSI related solar mechanisms are very subtle, often more dynamical than radiative in nature, and may be at best a second or third order "fine-tuning" effect for climate change in general.

As happens in the unforgiving world of science, people like Svensmark, Shaviv, Scafetta, Soon are no longer taken seriously due to some rather odd publications with some very odd analysis on these topics (citation counts, specifically ones in legitimate journals, may be a good proxy for their merit). It is interesting to see people with a real interest in climate revisit the subject and discuss these papers, but the fact remains that the sensitivity of CCN concentrations to the nucleation caused by GCR is not well established, and large-scale relationships between clouds and cosmic rays has not been established with high confidence. The people banking on such theories might convince themselves or some people on the internet of their legitimacy, but to actually advance as a scientific idea, it should be able to have some explanatory and predictive power that is borne out in observations, is robust to specific choices used in a study, and stand the test of scrutiny over time. This has not been done yet, nor has anyone quantified the radiative forcing of such changes (aside from the obvious logical fallacy in that finding a new forcing mechanism does not "replace" existing, well-understood ones).

CMC,

You claim that you are an atmospheric student. I am also looking to be an atmospheric/climate dynamics student. How can you say that,

ionization is most likely too weak to influence global-scale cloud cover and influence climate in any significant way.

When you also claim that there are a number of conflicting peer-reviewed publications on the matter.

What is your basis for the bolded portion of your post that I quoted? CERN has found an impact, though the magnitude of this impact is still uncertain, and there are many lines of evidence that point to a large GCR-influence on cloud cover and climate.

Yuri Stozhkov (who was also one of the authors in the CERN paper) et. al found that during large Forbush Decreases, there are precipitation decreases observed, suggesting that this is a cause from a sudden decrease in Cloud Cover.

Dragic et. al 2011 found that with Forbush Decreases exceeding a GCR decrease of 7%, a noticeable increase with the DTR was observed. This can only be explained through cloud cover decreases, since clouds reduce the DTR range, and a decrease in cloud cover would create an increase in the Diurnal Temperature Range.

Svensmark et. al 2009 used 17 Forbush Decreases (large and sudden decreases in Cosmic Rays after a Coronal Mass Ejection) after 1998 (since this is when AERONET started) that were above a 7% decrease, and compared these changes in GCRs to corresponding changes in aerosol particles. Aerosoles are the "seeds" to cloud formation. Without these, water vapor droplets would not be able to condense onto a physical substance to form a cloud. Svensmark et. al found that for each FD event analyzed, a sudden decrease in aerosoles was also observed. This indicates a significant GCR impact on the atmospheric composition.

Kniveton and Todd 2001

This paper evaluates whether there is empirical evidence to support the hypothesis that solar variability is linked to the Earth's climate through the modulation of atmospheric precipitation processes. Using global data from 1979–1999, we find evidence of a statistically strong relationship between cosmic ray flux (CRF), precipitation (P) and precipitation efficiency (PE) over ocean surfaces at mid to high latitudes. Both P and PE are shown to vary by 7–9% during the solar cycle of the 1980s over the latitude band 45–90°S. Alternative explanations of the variation in these atmospheric parameters by changes in tropospheric aerosol content and ENSO show poorer statistical relationships with P and PE. Variations in P and PE potentially caused by changes in CRF have implications for the understanding of cloud and water vapour feedbacks.

Shaviv 2005

Regardless of if it is Cosmic Rays or not, CMC, (though there is much evidence for a GCR-climate connection), an amplifying mechanism is needed for the sun-climate connection.

Over the 11-year solar cycle, small changes in the total solar irradiance (TSI) give rise

to small variations in the global energy budget. It was suggested, however, that different

mechanisms could amplify solar activity variations to give large climatic effects, a

possibility which is still a subject of debate. With this in mind, we use the oceans as

a calorimeter to measure the radiative forcing variations associated with the solar cycle.

This is achieved through the study of three independent records, the net heat flux

into the oceans over 5 decades, the sea level change rate based on tide gauge records over

the 20th century, and the sea surface temperature variations. Each of the records can

be used to consistently derive the same oceanic heat flux. We find that the total radiative

forcing associated with solar cycles variations is about 5 to 7 times larger than just

those associated with the TSI variations, thus implying the necessary existence of an amplification

mechanism, though without pointing to which one.

=================================================

So on what basis are you going with that the ionization from GCRs globally have a small impact on cloud cover formation? The CERN paper concluded that the ionization from GCRs could be quite large when averaged across the global troposphere.

[Snow_Miser]

A quick question for Snowlover or anyone else who might want to take a stab at this. My understanding of reading Svensmark's theory is that our solar system is orbiting around the center of our Galaxy which takes about 230 million years to make a full cycle. During the trek we will be going in and out of the spiral arms of the galaxy where more GCRs exist. It seems odd to me, those that point to 60 years of GCR data and say the Svensmark theory doesn't work since 60 years out of 230 million is such a small number. Looking at the last 60 years of GCR data it looks like there is little variation but would this not be expected since it would, in relation, be like only going .0165" in a mile long journey. In other words we have barely moved over the last 60 years.

For the record I neither accept nor deny Svensmark's theory.

Hey ben,

It's largely due to the fact that the increases in solar wind modulate the amount of GCRs, and has done so over a 60 year timeframe, as it's activity has increased during this timeframe.

This would reduce GCRs on Earth during the period in which solar activity increased, and cause warming, both of which have been observed.

[Snow_Miser]

Well, it was nice playing with you....kiss your credibility goodbye....the mention of Soon will get you:

It's the same red herring they will try and throw at any skeptical scientist's peer reviewed paper, so that they will not have to address the issues the scientific article brought up.

[WeatherRusty]

It's the same red herring they will try and throw at any skeptical scientist's peer reviewed paper, so that they will not have to address the issues the scientific article brought up.

Science addresses the skeptic's papers on a regular basis. Most of those papers fail the peer-review process.

When the evidence is stronger than, as you often put it, "suggestion" or correlation, then and only then will these solar modulated ideas become accepted theory. It is the responsibility of scientists to demonstrate the validity of these as of yet dubious claims in order to become accepted scientifically.

If and when that day arrives, rather than competing with or replacing greenhouse gas warming as an understood cause of global warming, the GCR theory will find it's proper place beside AGW as an additive factor. Just because GCRs may influence cloud amount is not a reason to reject or ignore the well founded physics and sciences of CO2 and land use change effects on climate.

[ben4vols]

Hey ben,

It's largely due to the fact that the increases in solar wind modulate the amount of GCRs, and has done so over a 60 year timeframe, as it's activity has increased during this timeframe.

This would reduce GCRs on Earth during the period in which solar activity increased, and cause warming, both of which have been observed.

Thanks for the answer. The solar stuff gives me a headache. The time scales are too large and the multiple movements of orbits is hard to keep track of. I need a nice clean animation of the Sun's orbit through the Milky Way and evidently the Sun also wobbles up and down across the Galactic Plane every 60 million years which also enhances GCR's. According to Shaviv's paper we are in the Orion Arm Spur of the galaxy and in above average GCR?

[Snow_Miser]

Thanks for the answer. The solar stuff gives me a headache. The time scales are too large and the multiple movements of orbits is hard to keep track of. I need a nice clean animation of the Sun's orbit through the Milky Way and evidently the Sun also wobbles up and down across the Galactic Plane every 60 million years which also enhances GCR's. According to Shaviv's paper we are in the Orion Arm Spur of the galaxy and in above average GCR?

According to Shaviv, we are in a small spiral arm.

The increase in solar activity is what has caused GCRs to decrease over the last 150 years.

He starts at around 3:15 into the video.

[Snow_Miser]

If and when that day arrives, rather than competing with or replacing greenhouse gas warming as an understood cause of global warming, the GCR theory will find it's proper place beside AGW as an additive factor. Just because GCRs may influence cloud amount is not a reason to reject or ignore the well founded physics and sciences of CO2 and land use change effects on climate.

Only one problem: There is absolutely no observational evidence that most of the warming that we have observed is due to CO2 or anthropogenic greenhouse gases.

[ben4vols]

According to Shaviv, we are in a small spiral arm.

The increase in solar activity is what has caused GCRs to decrease over the last 150 years.

He starts at around 3:15 into the video.

I was referencing his graph from the paper linked below. See figure 1.

LINK

[Snow_Miser]

I was referencing his graph from the paper linked below. See figure 1.

LINK

Thanks for clarifying. Future climate change should be interesting, considering that solar activity is going low, and GCRs are going high...

[cmc0605]

Snowlover, I was going to respond to your post directed at me but I am just going to end up being duped here. Statements like "There is absolutely no observational evidence that most of the warming that we have observed is due to CO2 or anthropogenic greenhouse gases" while simultaneously trying to support a very weak and tentative link between climate and cosmic rays, just indicates an unmoving faith in dismissing anthropogenic causality for the sake of dismissing anthropogenic causality. You have simply not read the literature in an objective fashion or are hoping to confuse readers here.

For other readers interested, the paper at http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00169.1 provides a pretty good review of the issues. In addition to many papers finding a disconnect between cosmic rays and cloudiness, as in the above paper and many references therein, correlations in GCR and cloudiness are confounded by a plethora of other dynamical and thermodynamical processes that can modify cloud properties, and some authors have attrivuted these weak links to other meteorological phenomena like ENSO or even artifiacts of data. Moreover, the relationship between cosmic ray induced ioniation is not uniform but exists only in a few limited geographical areas. The Svensmark 09 study was challenged by Laken et al. (2009), which also highlights that few Forbush decrease events have occurred during the satellite era ( about six) and the statistics are sensitive to how the Forbush events are selected. See also http://www.atmos-chem-phys.net/10/1885/2010/acp-10-1885-2010.html and http://www.agu.org/pubs/crossref/2009/2009GL037946.shtml on a lack of robust link. There are localized positive correlations that have been found (e.g., http://rspa.royalsocietypublishing.org/content/462/2068/1221.full), although inconsistency exists between the response time found in that study and the Svensmark 09 study.

Regarding mechanisms, the CERN results have been misrepresented by a number of people. They show GCR changes are unlikely to give a significant contribution to nucleation taking place in the continental boundary layer (not necessarily in the free troposphere), and field experiments tend to confirm this. It is also not trivial to disintangle GCR-induced nucleation from other nucleation causes, and the main mechanisms that have been proposed have only been tested by a few modeling studies simulating GCR changes during Forbush decreases or solar cycles. This is all in addition to the lack of trend since mid-century in cosmic rays.

The whole thing has made for some interesting science but extremely weak in terms of robust mechanisms and identified physics, and rests largely on correlations at localized sites which are often spurious or may be impacted by other factors. It also requires 4-5 steps in logic that begin with cosmic ray changes developing from changes in solar activity, all the way to the GCR-induced cloud changes having a radiative influence on climate. Some of the steps in logic can be justified, but they break down at multiple intermediate steps. Jeff Pierce had a few good guest posts at RealClimate explaining this in more detail.

Anyone trying to compare this with the explanatory and predictive framework of how GHGs impact climate instantly loses credibility. This is, however, an interesting exercise in psychology and the unmoving faith people will have in defending mechanisms with little support and even trying to use them to "replace" mechanisms with much support. There are thousands of papers over the last few decade examining the influence of CO2 on climate. while the cosmic ray stuff has fallen out of favor after a temporary reign of "sexiness."

Then again, I could just have different views in what I find "convincing"

[Snow_Miser]

Snowlover, I was going to respond to your post directed at me but I am just going to end up being duped here. Statements like "There is absolutely no observational evidence that most of the warming that we have observed is due to CO2 or anthropogenic greenhouse gases" while simultaneously trying to support a very weak and tentative link between climate and cosmic rays, just indicates an unmoving faith in dismissing anthropogenic causality for the sake of dismissing anthropogenic causality. You have simply not read the literature in an objective fashion or are hoping to confuse readers here.

Wow, I may disagree with your views, but never would I say that you are trying to deliberately confuse readers by suggesting that the effect of GCRs in the peer reviewed literature is unknown, while at the same time suggesting that GCRs probably have a minimal impact.

Provide one shred of observational evidence that Global Warming is mostly due to Anthropogenic Greenhouse Gases.

Note that there is a layer in the mid to upper troposphere in the Tropics that should warm the fastest at around 150-400 hPa.

There is one problem. There has been NO warming observed in this region since satellites started to measure this portion of the atmosphere.

Temperature change at 200hPa (c. 12 km height) between 20^oN and 20^oS since 1979, according to HadAT. The thin blue line shows the monthly values, while the thick blue line represents the simple running 37 month average, nearly corresponding to a running 3 yr average. The stippled red line shows the linear fit for the period shown, with basic statistics shown in the upper left corner of the diagram. The data were normalised by setting the average of their initial 120 months (10 years) from January 1979 to December 1988 = 0. Last month shown: March 2012. Last diagram update: 14 June 2012.

(Italics are from Dr. Ole Humlum's Climate4you.com Website...

I have given PLENTY of evidence to support my viewpoint, so it is not a very weak and tentative link between climate and cosmic rays, as you would like to wishfully think.

Looks like I am going to need to post 3 more studies to condtradict your 3 studies, which is a piece of cake.

Palle Bago and Butler 2001 found that GCRs are HIGHLY correlated to Low Level Clouds over the solar cycle, suggesting a close relationship between the two.

http://articles.adsa...0&filetype=.gif

They find that over 90% of the warming can be attributed to the direct and indirect variations in Solar Activity over the last 100-150 years.

Yu 2002

The indirect radiative forcing of atmospheric aerosols is sensitive to particle size and concentration, which are influenced significantly by nucleation processes. Via its role in aerosol formation, cosmic ray may affect the cloud condensation nuclei abundance and hence the global cloud properties and climate. Systematic variations in ionization rates due to the modulation of cosmic ray radiation by the solar cycle are sufficient to cause notable variations in aerosol production, and we find that the signs of such variations are altitude-dependent. Our study indicates that an increase in cosmic ray fluxes generally leads to an increase in particle production in the lower troposphere but a decrease in particle production in the upper troposphere. The main reason of such an altitude-dependent influence is that the dependence of particle production rate on ionization rate is a complex function of ionization rate itself, as well as precursor gas concentration and ambient conditions. The implications of altitude variations of cosmic ray-induced aerosol production on global cloudiness and climate are discussed. In addition to the reported positive correlation between cosmic ray variations and low cloudiness, our analysis reveals that high cloudiness may be anti-correlated with cosmic ray variations if volcano and El Niño impacts are excluded. The observed different correlations between cosmic ray variations and low, middle and high cloud anomalies appear to be consistent with the predicted different sensitivities of particle production to cosmic ray changes at different altitudes. A systematic change in global cloudiness may change the atmosphere heating profile, and if confirmed, may provide the external forcing needed to reconcile the different surface and troposphere temperature trends. Much more work is needed to understand how and how much the cosmic ray variations will affect the global cloud properties and climate.

Duplissy et. al 2010

In its Fourth Assessment Report, 2007, the Intergovernmental

Panel on Climate Change (IPCC) attributes more than

90% of the observed climate warming since 1900 to the rise

of anthropogenic greenhouse gases in the atmosphere (IPCC,

2007). Aerosols and clouds are recognised as representing

the largest uncertainty in the current understanding of climate

change. The IPCC estimates that changes of solar irradiance

(direct solar forcing) have made only a small (7%)

contribution to the observed warming. However, large uncertainties

remain on other solar-related contributions, such

as the effects of changes of ultra-violet (UV) radiation or

galactic cosmic rays on aerosols and clouds (Svensmark

and Friis-Christensen, 1997; Carslaw, Harrison and Kirkby,

2002; Lockwood and Fr¨ohlich, 2007; Kirkby, 2007; Enghoff

and Svensmark, 2008; Kazil, Harrison and Lovejoy, 2008;

Siingh, 2008).

So while there are large uncertainties that remain with GCRs and Climate, there is enough evidence to suggest that they have a meaningful impact on the atmospheric parameters.

The Agee et. al paper you posted is flawed because it relies on one set of cloud data, when there are many sets of cloud data available.

Regarding mechanisms, the CERN results have been misrepresented by a number of people. They show GCR changes are unlikely to give a significant contribution to nucleation taking place in the continental boundary layer (not necessarily in the free troposphere), and field experiments tend to confirm this. It is also not trivial to disintangle GCR-induced nucleation from other nucleation causes, and the main mechanisms that have been proposed have only been tested by a few modeling studies simulating GCR changes during Forbush decreases or solar cycles. This is all in addition to the lack of trend since mid-century in cosmic rays.

Yes they have. You have just misrepresented the conclusions of the CERN paper.

http://www.leif.org/...10343Kirkby.pdf

From the full paper.

They say that H2SO4 concentrations are not high enough to account for observed nucleation in the boundary layer. It means that something else other than H2SO4 is primarily responsible for the observed nucleation in the boundary layer. It does not say that the GCR changes are unlikely to give a significant impact on clouds.

Here are sections from the paper:

We find that ion induced

binary nucleation proceeds at a significant rate in the cool

temperatures of the free troposphere at atmospheric concentrations

of sulphuric acid, and may be an important process when ternary

vapour concentrations are low.

However, the fraction of these freshly nucleated particles that grow to

sufficient sizes to seed cloud droplets, as well as the role of organic

vapours in the nucleation and growth processes, remain open questions

experimentally.

Because the primary source of ions in the global

troposphere is galactic cosmic rays (GCRs), their role in atmospheric

nucleation is of considerable interest as a possible physical mechanism

for climate variability caused by the Sun

Ground-level GCR ionization substantially increases the nucleation

rate of sulphuric acid and sulphuric acid–ammonia particles, by

between twofold and tenfold or more, provided that the nucleation

rate lies below the limiting ion-pair production rate.

You sir, have inadvertantly misrepresented the paper. Am I going to claim that you are "deliberately trying to mislead readers" as you did with me, when I presented a hypothesis that disagreed with your views? No, because you have simply made a mistake.

There are thousands of papers over the last few decade examining the influence of CO2 on climate. while the cosmic ray stuff has fallen out of favor after a temporary reign of "sexiness."

If you believe that modeled studies of Carbon Dioxide have a greater weight than observational evidence of GCRs impacting the atmospheric parameters, then you have an odd definition of legitimacy.

[cmc0605]

You're grasping at straws now. You're also not thinking for yourself, as is evident in the regurgetation of talking points like the " tropical hot spot" issue which is discussed all throughout the internet, and of which many correct rebuttals to your assertions exist. Try to be a little bit original.

Of course, you just happened to get virtually everything about that issue wrong, including the physics of why we expect a "hotspot" (it doesn't make sense to call it a fingerprint of greenhouse gases, since it's an emergent property of moist convection); you misunderstoof what the figure you displayed actually shows (hint: it doesn't show that other forcings can't produce a hotspot, but rather that those forcings aren't important enough in recent decades to do so). You also didin't accurately summarize the observational part of the problem, which is much more uncertain than your absolute confidence in "no warming," and also depends on issues like location in the tropics (land vs. ocean) and timescale. There's at least half a dozen papers, including extensive review articles on this problem. But even if you cherry pick the ones you like, you even got the conclusion wrong. It is not even controversial that there has been warming in the upper troposphere, but rather the big issue is whether the warming has been consistent with adjustment to a moist adiabat (i.e., upper tropospheric warming amplified relative to the surface).

All this confusion is what happens when you read too many wingnut sources, copy/paste a lot of abstracts and figures, throw a lot of citations around, but don't actually do an objective research on the question. It's the same with comsic rays in this case. The fact is that the Kirkby results do not give insight into whether cloud changes induced by GCR have caused a radiative influence on Earth's energy budget. They've only looked so far at the study of embryonic particles, and those are far too small to seed cloud droplets. A freshly nucleated particle is of order 2 nm in size, CCN > 50 nm, and cloud droplets about 10 microns. They also need to identify those additional vapors that are important. But to quote Kirkby, "the correlations exist, but until a mechanism is established, it's no more than another geophysical correlation, of which there are a huge number in the literature." However, there is plenty of support now that for the majority of tropospheric conditions, the enhanced nucleation rate (which is of course influenced by ionization) is not large enough to ultimately affect cloud condensation nuclei. But you're free to oversell their results to people who may not know better, just as a lot of other people on blogs have done. Supplement this will the typical sniping of "models" (as if this means something) and complete disregard for countless papers and chapters on climate change attribution, and I think we have a recipe for someone unwilling to shake their unmoving faith in the lack of anthropogenic forcing.

There's really not much else to say. This isn't a scientific debate anymore, it's an exercise in the psychological response that people have when something threatens their faith, their fears, or their prejudices. They will descend to relying on "hot off the press" physics with over-the-top and unwarranted connections to climate change, astrology-like references with "spiral arm" and "supernova" theories that have little support, distorting the literature, and then pretend this all equates to decades of research on well established radiative transfer physics. Sorry, but I think the Willy Wonka video is the best response now.

[Snow_Miser]

The typical agitated response, a classic whe someone's arguments have been debunked and they have nothing left.

You're grasping at straws now. You're also not thinking for yourself, as is evident in the regurgetation of talking points like the " tropical hot spot" issue which is discussed all throughout the internet, and of which many correct rebuttals to your assertions exist. Try to be a little bit original.

What does originality have anything to do with this? What about your theory that you keep pushing about CO2 causing Climate Change? How original is that?

Of course, you just happened to get virtually everything about that issue wrong, including the physics of why we expect a "hotspot" (it doesn't make sense to call it a fingerprint of greenhouse gases, since it's an emergent property of moist convection); you misunderstoof what the figure you displayed actually shows (hint: it doesn't show that other forcings can't produce a hotspot, but rather that those forcings aren't important enough in recent decades to do so).

So then why has ZERO warming been observed in this altitude when we warmed globally if the faster warming rates at these altitudes in the mid to upper troposphere that the models showed are simply a product of any warming?

http://www.pas.roche...hed JOC1651.pdf

We examine tropospheric temperature trends of 67 runs from 22 ‘Climate of the 20th Century’ model

simulations and try to reconcile them with the best available updated observations (in the tropics during the satellite era).

Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by

more than twice the uncertainty of the model mean. In layers near 5 km, the modelled trend is 100 to 300% higher than

observed, and, above 8 km, modelled and observed trends have opposite signs.

It's the same with comsic rays in this case. The fact is that the Kirkby results do not give insight into whether cloud changes induced by GCR have caused a radiative influence on Earth's energy budget. They've only looked so far at the study of embryonic particles, and those are far too small to seed cloud droplets.

Another misrepresentation.

You're not getting better at this now, are you?

The particles initially produced are too small. However, these particles can grow to a large enough size to become CCNs. Kirkby et. al said that how many of the small particles produced become CCNs is still an open question.

http://www.leif.org/...10343Kirkby.pdf

However, the fraction of these freshly nucleated particles that grow to

sufficient sizes to seed cloud droplets, as well as the role of organic

vapours in the nucleation and growth processes, remain open questions

experimentally. These are important findings for the potential

link between galactic cosmic rays and clouds.

And you still have not provided the one tiny piece of evidence that supports that most of recent climate change is man-made.

Pity.

I was looking forward to it.

[WeatherRusty]

The typical agitated response, a classic whe someone's arguments have been debunked and they have nothing left.

What does originality have anything to do with this? What about your theory that you keep pushing about CO2 causing Climate Change? How original is that?

So then why has ZERO warming been observed in this altitude when we warmed globally if the faster warming rates at these altitudes in the mid to upper troposphere that the models showed are simply a product of any warming?

http://www.pas.roche...hed JOC1651.pdf

We examine tropospheric temperature trends of 67 runs from 22 ‘Climate of the 20th Century’ model

simulations and try to reconcile them with the best available updated observations (in the tropics during the satellite era).

Model results and observed temperature trends are in disagreement in most of the tropical troposphere, being separated by

more than twice the uncertainty of the model mean. In layers near 5 km, the modelled trend is 100 to 300% higher than

observed, and, above 8 km, modelled and observed trends have opposite signs.

Another misrepresentation.

You're not getting better at this now, are you?

The particles initially produced are too small. However, these particles can grow to a large enough size to become CCNs. Kirkby et. al said that how many of the small particles produced become CCNs is still an open question.

http://www.leif.org/...10343Kirkby.pdf

However, the fraction of these freshly nucleated particles that grow to

sufficient sizes to seed cloud droplets, as well as the role of organic

vapours in the nucleation and growth processes, remain open questions

experimentally. These are important findings for the potential

link between galactic cosmic rays and clouds.

And you still have not provided the one tiny piece of evidence that supports that most of recent climate change is man-made.

Pity.

I was looking forward to it.

The tropical middle troposphere "hot spot" arises as a consequence of a water vapor feedback to warming. It is nothing more than an alteration in lapse rate toward a more moist adiabat in a region of strong convection. The water vapor feedback is to warming rather than the cause of the warming. It is not a particular signature of CO2.

The proof of CO2 forcing is found in the physics. A 3.7W/m^2 forcing per doubling of CO2 derives from standard radiative transfer physics through the atmosphere. That 3.7 watts gives nearly 1.2C of warming at a Planck response of 0.3C/watt.. before feedback. If you deny this then you are in the minority of even the most ardent skeptics.

[Snow_Miser]

The tropical middle troposphere "hot spot" arises as a consequence of a water vapor feedback to warming. It is nothing more than an alteration in lapse rate toward a more moist adiabat in a region of strong convection. The water vapor feedback is to warming rather than the cause of the warming. It is not a particular signature of CO2.

Allow me to explain my argument.

The mid to upper troposphere warming the fastest is predicted because of the positive water vapor feedback in the tropics. However, the area in the mid to upper troposphere predicted to warm the fastest, has not warmed at all. This means that the climate might be more insensitive than what the models have projected, which matches up with results from Lindzen and Choi that show that the amount of energy being radiated out to the TOA VS. The temperature change in observations significantly deviates from the modeled projections. This conclusion can be reached because the positive water vapor feedback the models have are not present in reality.

This also matches up with Paltridge et. al 2009 which shows a decrease in RH everywhere at every atltitude, except the Tropics and the Northern Hemisphere at 925 mb, where RH values have been relatively stable.

The abstract reads:

Water vapor feedback in climate models is positive mainly because of their roughly constant relative humidity (i.e., increasing q) in the mid-to-upper troposphere as the planet warms. Negative trends in q as found in the NCEP data would imply that long-term water vapor feedback is negative—that it would reduce rather than amplify the response of the climate system to external forcing such as that from increasing atmospheric CO2. In this context, it is important to establish what (if any) aspects of the observed trends survive detailed examination of the impact of past changes of radiosonde instrumentation and protocol within the various international networks.

With this in mind, if the climate system is indeed more sensitive than climate models have modeled, then CO2 alone is not enough to nearly account for the warming observed. A larger factor is needed.

The scatter plot above shows the temperature anomaly plotted over the energy imbalances as measured by CERES over 2000-2007. The plot above also shows two patterns: Linear Striations and Radiative Spirals. The radiative spirals act to reduce the slope of the line, thus obscuring the true feedback and making the climate system appear to be more sensitive than it actually is (Spencer and Braswell 2008). The true feedback can be calculated by the slopes of the linear striations, which according to Spencer and Braswell is during a time when non-radiative forcings are the strongest, so the slopes of these lines are not contaminated by the radiative spirals (primarily from the Cloud Forcing). The slope of the striations is 8.3 w/m^2/Degree C, meaning that it would take 8.3 w/m^2 to warm the Earth's temperature up by 1 Degree C. This indicates significant negative feedback, since no feedback would correspond to a slope of approxmately 3.3 w/m^2/Degree C.

The senstiivty for a CO2 doubling as measured by CERES is approximately 0.44 Degrees C. This means that CO2 could have contributed to approximately 0.17 Degrees C of the long term warming trend observed so far.

A larger factor is needed to explain the warming observed, and the sun is an ample candidate for such a factor, since it has so many ways in which it can impact climate and the atmospheric parameters on Earth.

[cmc0605]

Sorry, but not even close, and certainly no cigar for you.

The lapse rate feedback is different from (though not independent of) the water vapor feedback. The latter is unambiguously positive. The Paltridge paper is not really seen as a useful contribution here, since it is well-known that reanalysis products are not suitable for monitoring long-term water vapor changes, and in fact the results differ depending on which re-analysis product you look at. In fact, the rest of them show a positive feedback, including JRA, MERRA, and ECMWF. But it's okay, you are free to cherry-pick the one analysis you like, and ignore the dozens of others...including the much more reliable satellite data. I would never expect an objective literature review after all.

But even your physics is off target. Suppose we decompose the water vapor feedback into two components. The first component is the water vapor response you'd get with a uniform warming of the troposphere. The second component is the "rest of the water vapor feedback" that you get when the lapse rate adjusts to a moist adiabat. The lapse rate feedback is negative in the global mean, since the amplified upper atmospheric warming can take up some of the slack in restoring equilibrium (so the surface does not need to warm as much). But the lapse rate feedback is larger than the second component of that water vapor feedback, and thus the lack of a tropical hotspot, all else remaining equal, would mean feedbacks were more positive. Of course, it is unlikely that all else would remain equal, since departure from a moist adiabat would trigger a large-scale destabilization of the tropics. I'm not really sure how feasible this scenario is, and it's not something that occurs during ENSO events for example. There's evidence that this is not what is really happening in the long-term and the disagreement between models and observations cannot be settled due to extremely large uncertainties in the radiosondes. As suspected, you have just cited papers that support an inconsistency, but a much more broad literature suggests we can't really tell right now. But there is no obvious discrepancy, and it has not really been explored what the implications for such a discrepancy would actually be. Skeptics don't know either, they just like pointing out model-obs mismatches because it's a "cool thing to do" and then make stuff up about "greenhouse fingerprints," connections to climate sensitivity which aren't at all self-evident, and the like. And you still keep confusing warming with amplified warming in the upper troposphere.

In a further effort to rely on minority papers, all of which have been thoroughly addressed in the literature (and whose criticisms you choose not to acknowledge), you are now just trying to grasp at straws to find SOMETHING that isn't anthropogenic CO2. In fact, Lindzen hypothesizes that clouds, not water vapor, are the main negative feedback acting here ( I would note that even he has stated that the models are probably better than the obs regarding the tropical hotspot). But heck, you can just make it negative water vapor too...throw in some cosmic rays into the mix, throw in some spital arm galaxy stuff, sit on the couch and hit play and watch a climate that makes absolutely no sense evolve in front of you. It's okay though, as long as it absolutely must not be CO2.

[PhillipS]

There is a new post on Skeptical Science relevant to this discussion - of course, the term 'discussion' may be inaccurate since Snowlover is just parroting denialist nonsense instead of exchanging information.

Here's an excerpt:

Scientists working on climate on a daily basis must have been rather astonished by the interview with Professor Fritz Vahrenholt (European Energy Review, May 2, free registration required). Vahrenholt, chief of RWE Innogy, self-proclaimed climate expert and author of the book Die Kalte Sonne (The Cold Sun), claims that “the contribution of CO2 to global warming is being exaggerated”. These claims, however, do not stand up to scientific scrutiny. We assess his ideas in the light of the scientific literature on the role of the sun versus other climate forcing factors. The dominant influence of greenhouse gases follows not only from their basic physical properties, but also from their “fingerprint” in the observed warming. The sun, in contrast, has not exhibited any warming trend over the past 50 years. The sun is thus not responsible for the warming seen during this period. Greenhouse gases in all likelihood are.

Of course, opinions differ regarding how well the IPCC assessment reflects the scientific understanding, with some claiming that IPCC overestimates the human contribution to global warming and the risks it poses, whereas others claim that these are underestimated. However, the main tenets of climate science, as described in working group 1 of the IPCC report, have proven to be robust: New research has confirmed the core conclusions, while the details are continuing to be filled in. Vahrenholt’s claim that the IPCC report is radically wrong is unfounded, and is mostly indicative of his views diverging from mainstream science.

This is not to say that no uncertainties remain; of course there are and in some cases they are inconveniently large. Inconvenient, not only because more research is required to further constrain these uncertainties, but also because the uncertainties go both ways. The human contribution to global warming could be somewhat smaller, or it could be somewhat larger than expected. Focussing only on aspects that downplay the anthropogenic contribution is closing one’s eyes for the whole picture.

Challenging the core tenets of climate science is easier said than done. Varenholt’s extraordinary claim requires extraordinary evidence. The least one would expect of such a claim is that it be put to the scientific test. Spectacular theories and speculations abound in books and on the internet, but most of them were not offered to the scientific community, or did not stand up to scrutiny if they were. Scientists routinely check each other’s work via the peer review process, which can be seen as a first test of scientific validity. From further discussions in the literature and other scientific fora the relative robustness of competing ideas is assessed. The most robust idea eventually gains acceptance. That is how science progresses. Surely the peer-review system is not perfect, but at least it is an organised process aimed at filtering what is possibly right from what is plainly wrong. Such a mechanism is lacking in the public debate; and that adds much to the public confusion about this and other complex scientific topics.

Now, would the ideas of prof. Vahrenholt stand up to scientific scrutiny? On the basis of the interview, we expect: no, they would not. However, we would still encourage him to submit his ideas for scientific review. That is where the physical forces and feedbacks in the climate system should be discussed. On the other hand, questions on how society and politics should respond cannot be answered by science, but should be discussed in the public and political debate. Unfortunately, Vahrenholt’s accusations like “we are being misinformed by the climate establishment” and “the whole purpose of the IPCC has been to get rid of the so-called Medieval Warm Period” betray him as being receptive to conspiracy theories, which are routinely echoed on the internet. In such a world view, any criticism by the scientific mainstream is of course only perceived as proof that his and similar views are being suppressed. This is often used as an excuse to not even try to submit one’s ideas to peer review.His book is criticized by scientists not because it would be politically incorrect, as Vahrenholt assumes, but because it is scientifically incorrect.

Now, if we take a closer look at the content of Vahrenholt’s theory, his key statements appear to be the following:

• The ‘hockey stick graph’ showing that global average temperatures are now higher than in the last 1500 or so years is flawed. The medieval warm period was about as warm as today, the Little Ice Age was globally very cold and both periods coincide with a more, respectively less active sun. Therefore, the IPCC underestimates the natural variations of our climate system.
  
• The IPCC fails to look at all the solar characteristics, focusing on sunspots and Total Solar Irradiation (TSI) only, while both fluctuations in the magnetic field and the amplifying feedbacks should also be taken into account.
  
• The sun has become more active over the past few hundred years, being responsible for a large part of the observed warming.
  
• The IPCC has underestimated the natural 60 years climate cycle dominated by the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO).
  
• Global warming has stopped since around 15 years.
  

On this basis, Vahrenholt claims that more warming is due to the sun and natural variability than the IPCC estimates, which automatically implies that less is due to CO2 than the IPCC says.

To begin with the last statement, the idea that global warming has stopped is a common misunderstanding, based on confusing short term variability with the long term underlying trend. Natural fluctuations, as caused by e.g. the solar cycle, volcanic eruptions, or by the El Nino/La Nina phenomenon, can mask the underlying trend in surface temperatures for more than a decade. When these effects are accounted for, as e.g. Foster and Rahmstorf did in 2011, the underlying trend is seen to continue unabated. Moreover, other measurements, e.g. of ice extent and of ocean heat content, confirm that global warming is continuing.

The solar activity has been well-measured, particularly since 1979 using satellites, and before that by indirect (“proxy”) measures. From these, the solar activity is seen to have been relatively stable over the past 50 years. That means, that even if amplified strongly, the sun’s variations could still not explain the strong global warming that started halfway the 1970’s. Measurements of cosmic rays, a favourite candidate for a solar amplification mechanism, also show no trend since at least 50 years. The robust evidence needed to become a serious scientific competitor for the dominant greenhouse mechanism is sorely lacking. It is true however, that the sun gained strength over the first half of the 20^th century, and thus contributed to warming seen during that time, as is also described in the IPCC report.

Figure showing temperature, CO2 and solar activity for the past 150 years, discussed in more detail here.

Various solar and climate physicists, like Lockwood, Haigh, Gray and others have published analyses indicating that the solar influence in the warming of the last half century is low or absent. These analyses include the magnetic field effects, which – in contrast to what Vahrenholt is saying – are not neglected by the IPCC. A few years ago, Pierce and Adams modeled the potential cloud forming effect of cosmic rays and found it wanting by more than an order of magnitude, even when the most favourable assumptions possible were made.

There is another indication to the statement that the sun’s role in warming is limited compared to the role of greenhouse gases: fingerprints. Each possible source of warming leaves a specific and characteristic fingerprint. For example, a solar fingerprint would be: warming throughout the atmosphere. A greenhouse gas fingerprint would be: warming at lower altitudes with simultaneous cooling of the stratosphere higher aloft, since in case of enhanced CO2 the stratosphere loses more infrared radiation than it receives from below. This is mainly a consequence of the temperature structure of the stratosphere. And guess what? Measurements clearly show a greenhouse gas fingerprint, not a solar one.

In addition, Vahrenholt claims that IPCC has underestimated natural variability, in particular a natural 60 year climate cycle manifesting in the purported Pacific Decadal Oscillation (PDO) and in the Atlantic Multidecadal Oscillation (AMO). However, Vahrenholt’s statement is based on curve fitting applied to a finite time series of (local) temperatures. It is well known that curve fitting to a series of chaotic signals can lead to apparent periodicities, but that these have no value for prediction unless they are supported by an underlying physical understanding.

From this quick analysis, it seems unlikely that Vahrenholt’s claims would stand up to scientific scrutiny. They should be taken seriously, but only as an idea that deserves further research and assessment, rather than as a scientific fact or theory that rises to the level of robustness of basic climate science. In that respect, the physical science basis of the IPCC 2007 is still strong. Vahrenholt’s ideas do not change that conclusion.

Dr. Rob van Dorland (KNMI)

Dr. Bart Verheggen (PBL)

[Snow_Miser]

There is a new post on Skeptical Sciencerelevant to this discussion - of course, the term 'discussion' may be inaccurate since Snowlover is just parroting denialist nonsense instead of exchanging information.

"Snowlover is parroting denialist nonsense"

I can see who is doing the parroting, by copying large sections from a cartoonist's blog.

[Snow_Miser]

The problem with assuming a positive water vapor feedback, CMC, is that even though with more water vapor would occur with warming, and warm the troposphere, there would also be more precipitation to reduce the impact of the increased water vapor. Most of the models that have the positive water vapor feedback also have a negative lapse rate feedback. So this would mean that if the lapse rate feedback is positive, that means that the water vapor feedback is close to none or even slightly negative.

Small water vapor changes in the middle to upper troposphere have a profound impact on the rate at which radiation leaves Earth. Source: Spencer and Braswell 1997. The amount of water vapor at these altitudes has decreased, according to observational evidence, indicating a negative feedback.

It should be noted that even with a negative lapse rate in the models, the models still manage to have a positive feedback overall from increased water vapor, thus suggesting that if the opposite were true, then you would get an overall negative water vapor feedback that would act to reduce the impacts that CO2 has on temperature.

[cmc0605]

I am not talking about the lapse rate sign. I'm talking about the lapse rate feedback and whether it is more positive, or more negative (radiatively) if there were no "hotspot" than in current models. The water vapor feedback is a secondary issue here and a distraction.

The lapse rate feedback is negative because the greenhouse effect depends on the temperature difference between the surface and upper atmosphere. In the extreme case where the upper atmosphere was made so warm that the vertical profile became isothermal, the greenhouse effect would collapse, and the whole profile would relax to the effective radiating temperature of the planet.

In global warming simulations, the upper atmosphere warms more than the surface because of the non-linear dependence between the amount at which a parcel releases its latent heat and its temperature. The amplified warm anomaly in the upper atmosphere can then radiate to space moreso than if it simply warmed at the same rate at the surface. Because of the enhanced emission aloft, that takes the slack off how much the surface needs to radiate away (i.e., heat up) in order to maintain planetary energy balance.

It naturally follows that is there was no tropical hotspot, then the feedback would be less negative than in current models. Less of a negative feedback means a higher sensitivity.

[Snow_Miser]

I am not talking about the lapse rate sign. I'm talking about the lapse rate feedback and whether it is more positive, or more negative (radiatively) if there were no "hotspot" than in current models. The water vapor feedback is a secondary issue here and a distraction.

The lapse rate feedback is negative because the greenhouse effect depends on the temperature difference between the surface and upper atmosphere. In the extreme case where the upper atmosphere was made so warm that the vertical profile became isothermal, the greenhouse effect would collapse, and the whole profile would relax to the effective radiating temperature of the planet.

In global warming simulations, the upper atmosphere warms more than the surface because of the non-linear dependence between the amount at which a parcel releases its latent heat and its temperature. The amplified warm anomaly in the upper atmosphere can then radiate to space moreso than if it simply warmed at the same rate at the surface. Because of the enhanced emission aloft, that takes the slack off how much the surface needs to radiate away (i.e., heat up) in order to maintain planetary energy balance.

It naturally follows that is there was no tropical hotspot, then the feedback would be less negative than in current models. Less of a negative feedback means a higher sensitivity.

The problem with assuming a positive water vapor feedback, CMC, is that even though with more water vapor would occur with warming, and warm the troposphere, there would also be more precipitation to reduce the impact of the increased water vapor. Most of the models that have the positive water vapor feedback also have a negative lapse rate feedback. So this would mean that if the lapse rate feedback is positive, that means that the water vapor feedback is close to none or even slightly negative.

Small water vapor changes in the middle to upper troposphere have a profound impact on the rate at which radiation leaves Earth. Source: Spencer and Braswell 1997. The amount of water vapor at these altitudes has decreased, according to observational evidence, indicating a strong negative water vapor feedback.

It should be noted that even with a negative lapse rate in the models, the models still manage to have a positive feedback overall from increased water vapor, thus suggesting that if the opposite were true, then you would get an overall negative water vapor feedback that would act to reduce the impacts that CO2 has on temperature.