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elizabeth25
2011-Jun-15, 08:43 AM
Three researchers studying three different aspects of the Sun have all come up with the same conclusion: the Sun’s regular solar cycles could be shutting down or going into hibernation. A major decrease in solar activity is predicted to occur for the next solar cycle (cycle #25), and our current solar cycle (#24) could be the last typical one.

Could we be heading towards a new ice age?

to read more click the link below

http://www.universetoday.com/86643/regular-solar-cycle-could-be-going-on-hiatus/#more-86643

TonyE
2011-Jun-15, 09:44 AM
Interesting! There has been lots of debate about this since cycle 24 was a bit slow in arriving. Time to start migrating south?

jlhredshift
2011-Jun-15, 11:10 AM
Could we be heading towards a new ice age?

In my best Professor Dumbledore voice, yes.... and no.

On a long term time scale, yes. On a generational time scale, i.e. human time scale, no. These things take a lot of time. We have been deglaciating from the Last Glacial Maximum for twenty two thousand years, plus or minus. We still have a lot to learn about how the Sun works, stay tuned.

Superluminal
2011-Jun-16, 12:36 AM
Could we be heading towards a new ice age?

to read more click the link below

http://www.universetoday.com/86643/regular-solar-cycle-could-be-going-on-hiatus/#more-86643

More than likely a Maunder minimum, or little ice age, such as what we had during the 16 and 1700's.

jlhredshift
2011-Jun-16, 01:22 AM
More than likely a Maunder minimum, or little ice age, such as what we had during the 16 and 1700's.

I would say that we probably do not know that for certain....yet. It is an interesting possibility to be able to monitor one of these things with the modern instruments and be able to measure the climatic response and then compare to past episodes that remain unexplained. But, most likely it will take longer to complete than most of us...well...have.

Tom Mazanec
2011-Jun-16, 02:19 AM
It seems a pity that Solar Probe Plus will be studying the sun from a few solar radii away just as it "turns off" it's most interesting features (if this is the beginning of the "Eddy Minimum").

tusenfem
2011-Jun-16, 04:54 AM
Actually, if the Sun is going into a new phase, then it is gret that Solar Probe Plus will be there to give us the best info on what is happening.

mikeg64
2011-Jun-16, 07:43 AM
I've thought of a possible benefit. If it is going into a quiet phase of less activity then that would give us time to make sense of models of the quiet sun:lol:

Bynaus
2011-Jun-16, 05:48 PM
1st, we don't know if the Maunder Minimum is in any way related to the Little Ice Age. If it is, and if the sun is indeed heading for another Maunder Minimum, the effects would be very small. See for example:

http://www.skepticalscience.com/How-would-Solar-Grand-Minimum-affect-global-warming.html

2nd, we would certainly be heading for an ice age for the long term (a few millennia) - if it weren't for humans. With the amount of CO2 we have inserted into the atmosphere (since industrialization, and possibly even before), and are likely to add within the next 50 years, it will take about 10'000 years until the CO2-level will fall back to (nearly) pre-industrial levels. The next ice age is already post-poned, and it may even be called off, depending on the amount of fossil fuel CO2 that ends up in the atmosphere. Whether there will be an ice age after that will depend critically on the question whether the ice caps will survive the next 10'000 years. If they don't, it is possible that humans will have ended the current glacial age (that lasted for the last 1.7 million years).

William
2011-Jun-16, 07:00 PM
1st, we don't know if the Maunder Minimum is in any way related to the Little Ice Age. If it is, and if the sun is indeed heading for another Maunder Minimum, the effects would be very small. See for example:

http://www.skepticalscience.com/How-would-Solar-Grand-Minimum-affect-global-warming.html

2nd, we would certainly be heading for an ice age for the long term (a few millennia) - if it weren't for humans. With the amount of CO2 we have inserted into the atmosphere (since industrialization, and possibly even before), and are likely to add within the next 50 years, it will take about 10'000 years until the CO2-level will fall back to (nearly) pre-industrial levels. The next ice age is already post-poned, and it may even be called off, depending on the amount of fossil fuel CO2 that ends up in the atmosphere. Whether there will be an ice age after that will depend critically on the question whether the ice caps will survive the next 10'000 years. If they don't, it is possible that humans will have ended the current glacial age (that lasted for the last 1.7 million years).

I guess we may have a chance to see by observation if a Solar "Maunder Minimum" is in any way related to the Little Ice Age. As noted in the forum, the sun was at its highest activity level in 10,000 years during the later half of the 20th century.

As there are cycles of warming periods and "little ice ages" that correlate with cosmogenic isotope changes, there is a smoking gun that points towards the sun as a possible forcing function. During the Little Ice Age there are accounts of increased precipitation, colder summers, and crop failure in addition to observed advances of alpine glaciers. There are similar accounts of evidence of warming such as increased agriculture production during the Medieval warm period.

The link that you provide (that alleges to disprove the solar changes affecting planetary climate) looks only at TSI and does not discuss the different solar changes that are alleged to affect planetary cloud cover.

There are other mechanisms discussed in published papers as to how solar magnetic cycle changes affect planetary temperature. As is noted in a number of papers, there was during the later part of the 20th century a reduction in planetary cloud cover that correlates with an increase in solar wind bursts. (Solar wind bursts are alleged to remove cloud forming ions via the mechanism that is referred to as electroscavenging. The solar wind bursts create a space charge differential in the ionosphere which in turn creates a potential difference which removes the cloud forming ions.)

Comment:
The observational facts concerning the glacial/interglacial cycle should likely be discussed in another thread.

There are three different lines of solar research that indicate the sun is rapidly moving to a "Maunder Minimum" (See solar cycle 24 for details). The subject of this thread is will a change from the highest solar activity in 10,000 years to a Maunder Minimum have an observable influence on climate on the earth.

I see in the Canadian province of Saskatchewan that due to a late spring, high winter snow fall, and very heavy spring rains 40% of the wheat crop will not be seeded which is the worst seeding record in 50 years. I believe there are similar problems in other provinces and in the Northern US states. There is a record snow pack in the West coast mountains which is persisting due to the cold and cloudy spring. What will be interesting is to see if this is the new weather pattern or if we revert back to warm weather.

jlhredshift
2011-Jun-17, 12:12 AM
As there are cycles of warming periods and "little ice ages" that correlate with cosmogenic isotope changes, there is a smoking gun that points towards the sun as a possible forcing function.

My Bold

Could I request the peer reviewed papers "that correlate" from you.

I have from time to time looked into this a little bit and my understanding is the solar signal that is looked for is Be10 in corals and the problem is dating any abundances tight enough, i.e. resolution, because of the reservoir effect and the fact that shell is notoriously difficult to carbon date. The other isotopes just do not have a resolution to get inside of a millenia or tighter.

Trakar
2011-Jun-17, 01:40 AM
I guess we may have a chance to see by observation if a Solar "Maunder Minimum" is in any way related to the Little Ice Age. As noted in the forum, the sun was at its highest activity level in 10,000 years during the later half of the 20th century.

As there are cycles of warming periods and "little ice ages" that correlate with cosmogenic isotope changes, there is a smoking gun that points towards the sun as a possible forcing function. During the Little Ice Age there are accounts of increased precipitation, colder summers, and crop failure in addition to observed advances of alpine glaciers. There are similar accounts of evidence of warming such as increased agriculture production during the Medieval warm period.

The link that you provide (that alleges to disprove the solar changes affecting planetary climate) looks only at TSI and does not discuss the different solar changes that are alleged to affect planetary cloud cover.

There are other mechanisms discussed in published papers as to how solar magnetic cycle changes affect planetary temperature. As is noted in a number of papers, there was during the later part of the 20th century a reduction in planetary cloud cover that correlates with an increase in solar wind bursts. (Solar wind bursts are alleged to remove cloud forming ions via the mechanism that is referred to as electroscavenging. The solar wind bursts create a space charge differential in the ionosphere which in turn creates a potential difference which removes the cloud forming ions.)

Comment:
The observational facts concerning the glacial/interglacial cycle should likely be discussed in another thread.

There are three different lines of solar research that indicate the sun is rapidly moving to a "Maunder Minimum" (See solar cycle 24 for details). The subject of this thread is will a change from the highest solar activity in 10,000 years to a Maunder Minimum have an observable influence on climate on the earth.

I see in the Canadian province of Saskatchewan that due to a late spring, high winter snow fall, and very heavy spring rains 40% of the wheat crop will not be seeded which is the worst seeding record in 50 years. I believe there are similar problems in other provinces and in the Northern US states. There is a record snow pack in the West coast mountains which is persisting due to the cold and cloudy spring. What will be interesting is to see if this is the new weather pattern or if we revert back to warm weather.

A big issue is that the LIA seems to have been mostly a northern hemisphere issue and predominantly focussed around the N. Atlantic, which would seem to rule out a general TOA reduction of solar radiations. Increased higher lattitude volcanism and perhaps some cyclic atmospheric and oceanic current issues seem a better fit for LIA causatives. The rise and fall of total solar radiation between active and quiescent periods generally isn't sufficient to produce the types of effects we see in most planetary climate events on its own.

Superluminal
2011-Jun-17, 02:07 AM
Are there any reliable records of what happened in the southern hemisphere during the Little Ice Age?

Tensor
2011-Jun-17, 02:10 AM
The link that you provide (that alleges to disprove the solar changes affecting planetary climate) looks only at TSI and does not discuss the different solar changes that are alleged to affect planetary cloud cover.

LOL, before, in another thread, you claimed it was Galactic Cosmic Rays (GCR) that caused changes in the cloud cover. Now you change it to push the solar wind bursts angle, after it was shown that the previous correlation claimed with GCR was not seen in the years after the original paper. Since one affect the other, why don't you just stick with claiming one or the other. As for a link, there is always this paper (http://stephenschneider.stanford.edu/Publications/PDF_Papers/Laut2003.pdf) which pretty much refutes it.


There are other mechanisms discussed in published papers as to how solar magnetic cycle changes affect planetary temperature. As is noted in a number of papers, there was during the later part of the 20th century a reduction in planetary cloud cover that correlates with an increase in solar wind bursts.

To quote from a paper by Dr Tinsley (since he is the proponent of electroscavenging):

From Tinsley and Wu (2005)
"Clearly there is a great deal of modeling that is needed in
order to provide quantitative relationships between
atmospheric ionization and macroscopic clouds properties.
However, models of the radiative and dynamical
consequences for climate of estimated precipitation and
cloud cover changes could be made with present
capabilities. Improved cloud cover and precipitation data
covering more solar cycles would be useful for validating
the present observational results, and as more accurate
inputs into global climate models"

In other words, Dr. Tinsley has NO quantitative evidence that any kind of solar variance or solar cycle has had an effect on global climate. He thinks he may have some evidence, there might be something there, but he doesn't, and doesn't claim to.


(Solar wind bursts are alleged to remove cloud forming ions via the mechanism that is referred to as electroscavenging.

Yes, alledged. Let me clear that up. There is NO definitive evidence that electroscavenging has anything to do with solar wind bursts or cloud formation. Or, for a better quote, from Roldugin and Tinsley(2004)

“It is however more unlikely that ‘electroscavaging’ has a global effect on cloud generation and ultimately on global climate although there is some limited observational evidence to suggest that this process can have an additional influence on atmospheric dynamics."

Trakar
2011-Jun-17, 02:25 AM
Are there any reliable records of what happened in the southern hemisphere during the Little Ice Age?

Reliable as the vast majority of the records for most of the Northern Hemisphere over the same time periods.

William
2011-Jun-17, 02:29 AM
A big issue is that the LIA seems to have been mostly a northern hemisphere issue and predominantly focussed around the N. Atlantic, which would seem to rule out a general TOA reduction of solar radiations. Increased higher lattitude volcanism and perhaps some cyclic atmospheric and oceanic current issues seem a better fit for LIA causatives. The rise and fall of total solar radiation between active and quiescent periods generally isn't sufficient to produce the types of effects we see in most planetary climate events on its own.

No. The Little Ice Age and Medieval Warm period were a global phenomena.

http://www.int-res.com/articles/cr2003/23/c023p089.pdf


ABSTRACT: The 1000 yr climatic and environmental history of the Earth contained in various proxy records is reviewed. As indicators, the proxies duly represent local climate. Because each is of a different nature, the results from the proxy indicators cannot be combined into a hemispheric or global quantitative composite. However, considered as an ensemble of individual expert opinions, the assemblage of local representations of climate establishes both the Little Ice Age and Medieval Warm Period as climatic anomalies with worldwide imprints, extending earlier results by Bryson et al. (1963), Lamb (1965), and numerous intervening research efforts. Furthermore, the individual proxies can be used to address the question of whether the 20th century is the warmest of the 2nd millennium locally. Across the world, many records reveal that the 20th century is probably not the warmest nor a uniquely extreme climatic period of the last millennium.



The figures show the results from Table 1 for the Little Ice Age (Fig. 1), Medieval Warm Period (Fig. 2) and the nature of the 20th century’s change (Fig. 3). The figures graphically emphasize the shortage of climatic information extending back to the Medieval Warm Period for at least 7 geographical zones: the Australian and Indian continents, the SE Asian archipelago, large parts of Eastern Europe/Russia, the Middle Eastern deserts, the tropical African and South American lowlands (although the large number of available borehole-heat flow measurements in Australia seems adequate for the reconstruction of ground temperatures back to medieval times; see Huang et al. 2000). Therefore, our conclusions are provisional


Fig. 1 indicates that Little Ice Age exists as a distinguishable climate anomaly from all regions of the world that have been assessed. Only 2 records—tree ring growth from western Tasmania and isotopic measurements from ice cores at Siple Dome, Antarctica— do not exhibit any persistent climatic change over this period (although the western Tasmania reconstruction contains an exceptionally cold decade centered around 1900; Cook et al. 2000). Fig. 2 shows the Medieval Warm Period with only 2 negative results. The Himalayan ice core result (Thompson et al. 2000) seems unambiguous, but the tree-ring proxy data from Lenca, southern Chile (Lara & Villalba 1993) is countered by nearby evidence of the Medieval Warm Period (Villalba 1990, 1994).



Fig. 3 shows that most of the proxy records do not suggest the 20th century to be the warmest or the most extreme in their local representations. There are only 3 unambiguous findings favoring the 20th century as the warmest anomaly of the last 1000 yr—the records from the Dyer Plateau, Antarctica, the Himalayas and Mongolia (Thompson et al. 1994, 2000, D’Arrigo et al. 2001). An important, seemingly counter-intuitive, feature of Fig. 3 is the large number of uncertain answers compared to the 2 prior questions, perhaps partly owing to inaccurate calibration between proxy and instrumental data. Also, another feature of the result is the many cases in which the warmest or most extreme climatic anomalies in the proxy indicators occurred in the early to mid-20th century (‘Yesa’), rather than sustaining throughout the century.

William
2011-Jun-17, 02:36 AM
LOL, before, in another thread, you claimed it was Galactic Cosmic Rays (GCR) that caused changes in the cloud cover. Now you change it to push the solar wind bursts angle, after it was shown that the previous correlation claimed with GCR was not seen in the years after the original paper. Since one affect the other, why don't you just stick with claiming one or the other. As for a link, there is always this paper (http://stephenschneider.stanford.edu/Publications/PDF_Papers/Laut2003.pdf) which pretty much refutes it.

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I am not sure what paper your are quoting from. Tinsley includes a graph that shows planetary cloud cover closing tracking GCR levels (tracking at 99.9% significance level) up until around 1994 at which time solar wind bursts increased and there was a net reduction in planetary cloud cover.

Sometimes it is helpful to refer to the data and logic rather than quoting scientific words as if it is scripture.

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

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


All cloud types show a linearly decreasing trend over the study period, with the low-level clouds having the largest trend, equal to −3.9±0.3% in absolute values or −9.9±0.8% per decade in relative terms. Of course, there are still some uncertainties, since the changes in low-level clouds derived from the ISCCP-D2 data, are not necessarily consistent with changes derived from the second Stratospheric Aerosols and Gas Experiment (SAGE II, Wang et al., 2002) and synoptic observations (Norris, 1999). Nevertheless, note that SAGE II tropical clouds refer to uppermost opaque clouds (with vertical optical depth greater than 0.025 at 1.02μm), while the aforementioned synoptic cloud observations are taken over oceans only. The midlevel clouds decreased by 1.4±0.2% in absolute values or by 6.6±0.8% per decade in relative terms, while the high-level ones also decreased by 1.2±0.4% or 3±0.9% per decade in relative terms, i.e. less than low and middle clouds. Thus, the VIS/IR mean tropical (30_ S–30_ N) low-level clouds are found to have undergone the greatest decrease during the period 1984–2000, in agreement with the findings of Chen et al. (2002) and Lin et al. (2004).

William
2011-Jun-17, 03:06 AM
When there are multiple mechanisms if the observer does not understand the mechanisms observations at one particular period may be misinterrupted as there can be a mechanism change.

For the period 1983 to 1994 closely correlates with GCR levels. As I noted from the period 1994 to 2003 cloud cover is reduced and total planetary cloud cover.

Curiously the largest net change in solar activity in roughly 8000 years is occurring. We can therefore in addition to arguing about what to expect, wait and discuss actual observations.

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


Fig. 2 shows the global annual averages of GCR induced ionization in the atmosphere and low cloud amounts for the period July 1983–June 2000 (ionization data is only updated to December 2000). A quick look at the data reveals the good agreement between those two quantities from 1983 to 1994, however, from 1995 to 2000 the correspondence breaks. (my comment due to the solar wind burst which create a space charge differential that rooms cloud forming ions.) Due to the Earth’s magnetic field, the flux of galactic cosmic rays is reduced at lower latitudes and reaches its maximum over the magnetic poles. If cosmic rays affect clouds we would expect the effect to be strongest in polar regions and weakest at the equator. This latitudinal effect was first corroborated by Svensmark and Friis-Christensen (1997) for the total cloud cover. However, later work has shown that the correlation of total cloud cover and cosmic rays was not maintained with later (post-1991) satellite data, whereas that for low cloud was (Palle´ and Butler, 2000; Sun and Bradley, 2002). Palle´ and Butler (2000) found that the correlation for low clouds was stronger in mid-latitude and equatorial belts and weaker in the polar regions. As there were some indications that the low clouds in liquid phase were responsible for the correlation (Palle´ , 2001; Palle´ and Butler, 2000), the reduction in the correlation coefficients poleward was attributed to two factors: (1) the lack of clouds in the liquid phase over the poles and (2) to a reduced reliability of the polar data due to ground ice coverage. The small drop in the degree of correlation at the equator was thought to be due to an increased shielding in the cosmic ray flux (Svensmark and Friis-Christensen, 1997).


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 an approx. 200 kV positive charge of the ionosphere compared to Earth. This large voltage difference, in turn, necessitates a return current which must pass through the regions of the atmosphere where clouds are formed. As cosmic rays are the principal agent of ionization in the atmosphere above 1 km altitude, any modulation of the GCR flux due to solar activity is likely to affect the transport of charge to complete the global electrical circuit. Tinsley and Yu (2003) discuss how the build up of electrostatic ccondensation nuclei (CCN) by droplets, and how this can lead to greater rates of precipitation and a reduction in cloud cover.harge at the tops and bottoms of clouds could affect the scavenging of ice forming nuclei (IFN) and cloud ...

Trakar
2011-Jun-17, 03:31 AM
No. The Little Ice Age and Medieval Warm period were a global phenomena.

http://www.int-res.com/articles/cr2003/23/c023p089.pdf

This paper an its conclusions have been discredited by mainstream science. Its publication with its numerous errors and flaws resulted in the resignation of three of the journal's leading editors over the manner in which one editor subverted the peer-review process and pushed through its publication despite the errors and flaws it was known to possess, and given the complaints of the treatment and interpretations that Soon and Baliunas rendered in their work of the papers and authors they cited. This probably isn't an appropriate thread to pursue a full discussion of this papers flaws or the shennanigans which led to its publication in a journal that has recieved a lot of attention over its open political agenda/slant during this timeframe. In short, however, the paper and many of its findings are at serious odds with mainstream climate science. If you would care to take this to a more appropriate thread, or create one, I would be happy to discuss the paper and its problems in more detail.

Wiki is to be taken with the appropriate precautions, but it has a page discussing many of these issues and more at: http://en.wikipedia.org/wiki/Soon_and_Baliunas_controversy

If you wish to argue against the mainstream scientific understandings please send me a notice when you have the ATM thread started.

Tensor
2011-Jun-17, 04:19 AM
LOL, before, in another thread, you claimed it was Galactic Cosmic Rays (GCR) that caused changes in the cloud cover. Now you change it to push the solar wind bursts angle, after it was shown that the previous correlation claimed with GCR was not seen in the years after the original paper. Since one affect the other, why don't you just stick with claiming one or the other. As for a link, there is always this paper (http://stephenschneider.stanford.edu/Publications/PDF_Papers/Laut2003.pdf) which pretty much refutes it. I am not sure what paper your are quoting from. Tinsley includes a graph that shows planetary cloud cover closing tracking GCR levels (tracking at 99.9% significance level) up until around 1994 at which time solar wind bursts increased and there was a net reduction in planetary cloud cover.

I have no idea what you are talking about. By what you quoted, I did not quote from another paper, I just gave a link, (which is still there) showing that the correlation that you provided from Tinsley's chart, isn't there.

And about those solar wind bursts, any kind of actual evidence for them?



Sometimes it is helpful to refer to the data and logic rather than quoting scientific words as if it is scripture.

You mean like you keep doing about the wind bursts or cloud correlations and Galactic Cosmic Rays/Solar changes? Even though there have been quite a few papers presented to you as refutations of that idea. Not to mention, the admittance of Tinsley that his research hasn't provided any quantitative evidence for a correlation.

And besides, the only place I quoted from, were from Tinsley's papers. Or are you suggesting that we should only pick and chose what we take from Tinsley's papers? Are you suggesting that if Tinsley has a chart you think supports your personal ideas, you'll accept it, but if he says he doesn't have any actual quantitative support for his claims, that he is just suggesting that he might have something down the road, if he can validate his current observations and tighten up his hypothesis, we should ignore thatt? Is that what you're saying?


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

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

And this paper has what to do with solar wind bursts? Yes, that's right, nothing. There is nothing in that paper about solar wind bursts. Do you have anything that ties this paper with solar wind bursts?

William
2011-Jun-17, 04:50 AM
I have no idea what you are talking about. By what you quoted, I did not quote from another paper, I just gave a link, (which is still there) showing that the correlation that you provided from Tinsley's chart, isn't there.

And about those solar wind bursts, any kind of actual evidence for them?




Yes there is observational evidence (see below) that there was an increase in solar wind bursts and that planetary temperature correlates with the solar wind bursts. There is also observational evidence that post 1994 there was a drop in planetary cloud cover. What is the alternative explanation for something that changed post 1994 to explain the drop in planetary cloud cover.



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.



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.


See section 5a) Modulation of the global circuit in this review paper, by solar wind burst and the process electroscavenging where by increases in the global electric circuit remove cloud forming ions.

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

Tensor
2011-Jun-17, 05:13 AM
When there are multiple mechanisms if the observer does not understand the mechanisms observations at one particular period may be misinterrupted as there can be a mechanism change.

For the period 1983 to 1994 closely correlates with GCR levels. As I noted from the period 1994 to 2003 cloud cover is reduced and total planetary cloud cover.

Curiously the largest net change in solar activity in roughly 8000 years is occurring. We can therefore in addition to arguing about what to expect, wait and discuss actual observations.

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

Yeah, we can do that, but every time you put out one of your discredited ideas, I'll be more than happy to put a link or links to the papers that discredit the idea. For instance, that second quote in your post. The comment about the paper by Tinsley and Yu in 2003 "Effect of particle flux variations on clouds and climate"? What was that you said about quoting words as if they're scripture? Well, here's a written QUOTE by Tinsley himself. Not an explaination of what Tinsley is claimed to have said happens, but a real, actual written statement within a paper Tinsley wrote in the conclusion area of the paper:

From Tinsley and Wu (2005)Atmospheric Ionization and Clouds as Links Between Solar Activity and Climate (Actually, this was 2006, but it does not have a date on it and I misread the url with the date. Much too small for me to see clearly)
"Clearly there is a great deal of modeling that is needed in
order to provide quantitative relationships between
atmospheric ionization and macroscopic clouds properties.
However, models of the radiative and dynamical
consequences for climate of estimated precipitation and
cloud cover changes could be made with present
capabilities. Improved cloud cover and precipitation data
covering more solar cycles would be useful for validating
the present observational results, and as more accurate
inputs into global climate models"

In other words, Dr. Tinsley has NO quantitative evidence that any kind of solar variance or solar cycle has had an effect on global climate. He thinks he may have some evidence, there might be something there, but he doesn't, and doesn't claim to.

Or, for a better quote, from another paper with Tinsley as author, Roldugin and Tinsley(2004) "Atmospheric transparency changes associated with solar wind-induced atmospheric electricity variations":
“It is however more unlikely that ‘electroscavaging’ has a global effect on cloud generation and ultimately on global climate although there is some limited observational evidence to suggest that this process can have an additional influence on atmospheric dynamics."

Again, Tinsley admits that there is NO evidence for, in this case, a Global effect for electroscavaging. So, no matter how much you keep claiming there's some sort of effect, even one of the leading proponents of that effect, admits that there isn't much observational evidence for it.

William
2011-Jun-17, 05:21 AM
We live on the same planet. We can determine if the solar magnetic cycle has a significant effect on planetary climate by observing.

It does appear in the past solar magnetic cycle changes affected planetary climate.

I am interested in the current solar change and I am interested in the mechanisms by which solar magnetic field changes are alleged to modulate planetary climate. I am interested in comparing and discussing observations to predictions.

This is the largest solar magnetic cycle change in at least 8000 years.

From Solanki, Usokin, Kromer, Shussler, Beer's, 2004 paper

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



"Unusual activity of the Sun during recent decades compared to the previous 11,000 years"

"According to our reconstruction, the level of solar activity during the last 70 years is exceptional, and the previous period of equally high activity occurred more than 8000 years ago. We find during the past 11,400 years the Sun spent only of the order of 10% of the time at a similar high level of magnetic activity and almost all of the earlier high-activity periods were shorter than the present episode."


http://scholar.google.com/url?sa=U&q=http://www.gg.rhbnc.ac.uk/elias/teaching/VanGeel.pdf



"A number of those Holocene climate cooling phases... most likely of a global nature (eg Magney, 1993; van Geel et al, 1996; Alley et al 1997; Stager & Mayewski, 1997) ... the cooling phases seem to be part of a millennial-scale climatic cycle operating independent of the glacial-interglacial cycles (which are) forced (perhaps paced) by orbit variations."

"... we show here evidence that the variation in solar activity is a cause for the millennial scale climate change."

Last 40 kyrs
Figure 2 in paper. (From data last 40 kyrs)... "conclude that solar forcing of climate, as indicated by high BE10 values, coincided with cold phases of Dansgaar-Oeschger events as shown in O16 records"

Recent Solar Event
"Maunder Minimum (1645-1715) "...coincides with one of the coldest phases of the Little Ice Age... (van Geel et al 1998b)

Periodicity
"Mayewski et al (1997) showed a 1450 yr periodicity in C14 ... from tree rings and ...from glaciochemicial series (NaCl & Dust) from the GISP2 ice core ... believed to reflect changes in polar atmospheric circulation.."

Tensor
2011-Jun-17, 05:27 AM
See section 5a) Modulation of the global circuit in this review paper, by solar wind burst and the process electroscavenging where by increases in the global electric circuit remove cloud forming ions.

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

Did your read the paper, other than looking at the charts? If so, can you please explain why they say (and I've noted this for the third time)


"Clearly there is a great deal of modeling that is needed in
order to provide quantitative relationships between
atmospheric ionization and macroscopic clouds properties.

However, models of the radiative and dynamical
consequences for climate of estimated precipitation and
cloud cover changes could be made with present
capabilities.

Improved cloud cover and precipitation data
covering more solar cycles would be useful for validating
the present observational results, and as more accurate
inputs into global climate models"

In other words, why is Dr. Tinsley saying he has NO quantitative evidence that any kind of solar variance or solar cycle has had an effect on global climate, if he thinks he does?. He thinks he may have some evidence, there might be something there, but he isn't sure enough to claim he does, and he doesn't actually claim to have the evidence.

What part of "Clearly there is a great deal of modeling that is needed in order to provide quantitative relationships between atmospheric ionization and macroscopic clouds properties" makes you think that he actually thinks he has evidence?

What part of "Improved cloud cover and precipitation data covering more solar cycles would be useful for validating the present observational results" makes you think that Tinsley believes his results are valid, if he thinks more results would be useful to validate his current observations?

William
2011-Jun-17, 05:47 AM
Did your read the paper, other than looking at the charts? If so, can you please explain why they say (and I've noted this for the third time)


In other words, why is Dr. Tinsley saying he has NO quantitative evidence that any kind of solar variance or solar cycle has had an effect on global climate, if he thinks he does?. He thinks he may have some evidence, there might be something there, but he isn't sure enough to claim he does, and he doesn't actually claim to have the evidence.

What part of "Clearly there is a great deal of modeling that is needed in order to provide quantitative relationships between atmospheric ionization and macroscopic clouds properties" makes you think that he actually thinks he has evidence?

What part of "Improved cloud cover and precipitation data covering more solar cycles would be useful for validating the present observational results" makes you think that Tinsley believes his results are valid, if he thinks more results would be useful to validate his current observations?

Tensor,

Attached is a more recent paper by Tinsley. The paper other paper you linked to discusses Jz's affect on the transparency of the atmosphere which is different than Jz's affect on planetary cloud cover.

Tinsley's research and analysis supports the assertion that GCR levels significantly affect planetary cloud cover and the electroscavenging mechanism.

As noted above we do not need to argue. We can discuss observations and compare the observations to the predictions to determine which hypothesis is correct.



https://www.utdallas.edu/physics/faculty/tinsley/Role%20of%20Global%20Circuit.pdf


The role of the global electric circuit in solar and internal forcing of clouds and climate
Brian A. Tinsley a,*, G.B. Burns b, Limin Zhou


Reports of a variety of short-term meteorological responses to changes in the global electric circuit associated with a set of disparate inputs are analyzed. The meteorological responses consist of changes in cloud cover, atmospheric temperature, pressure, or dynamics. All of these are found to be responding to changes in a key linking agent, that of the downward current density, Jz, that flows from the ionosphere through the troposphere to the surface (ocean and land). As it flows through layer clouds, Jz generates space charge in conductivity gradients at the upper and lower boundaries, and this electrical charge is capable of affecting the microphysical interactions between droplets and both ice-forming nuclei and condensation nuclei.


Four short-term inputs to the global circuit are due to solar activity and consist of (1) Forbush decreases of the galactic cosmic ray flux; (2) solar energetic particle events; (3) relativistic electron precipitation changes; and (4) polar cap ionospheric convection potential changes. One input that is internal to the global circuit consists of (5) global ionospheric potential changes due to changes in the current output of the highly electrified clouds (mainly deep convective clouds at low latitudes) that act as generators for the circuit. The observed short-term meteorological responses to these five inputs are of small amplitude but high statistical significance for repeated Jz changes of order 5% for low latitudes increasing to 25–30% at high latitudes. On the timescales of multidecadal solar minima, such as the Maunder minimum, changes in tropospheric dynamics and climate related to Jz are also larger at high latitudes, and correlate with the lower energy component ( 1 GeV) of the cosmic ray flux increasing by as much as a factor of two relative to present values. Also, there are comparable cosmic ray flux changes and climate responses on millennial timescales.

The persistence of the longer-term Jz changes for many decades to many centuries would produce an integrated effect on climate that could dominate over short-term weather and climate variations, and explain the observed correlations. Thus, we propose that mechanisms responding to Jz are a candidate for explanations of sun–weather–climate correlations on multidecadal to millenial timescales, as well as on the day-to-day timescales analyzed here.



Atmospheric Transparency Changes Associated with Solar Wind-Induced Atmospheric Electricity Variations
V. C. Roldugin and B. A. Tinsley
Variations in atmospheric transmission of several percent in nominally clear air are found to accompany solar wind events associated with variations on the day-to-day timescale in the flow of vertical current density (Jz ) in the global electric circuit. The effect has been observed only for stations at high latitudes (>55 ºN). Increases in transmission are present when inferred Jz decreases occurred without changes in tropospheric ion production. These events occurred when there was a high loading of stratospheric aerosols. Responses of opposite sign, i.e., decreases in transmission, are present when Forbush decreases of galactic cosmic ray flux occur, but only during periods of low stratospheric aerosol loading. Forbush decreases are associated with both tropospheric ion production decreases and Jz decreases. Similar effects are present on the 11-year solar cycle, with climate consequences that have yet to be analyzed. The mechanisms for these phenomena are not understood, but the nature of the observations suggests that explanations should be sought in terms of theories of the effects of electric charge on the formation of aerosols, and/or effects of charged aerosols on the microphysics of vapor-water-ice conversions.

mikeg64
2011-Jun-17, 07:23 AM
Are there any reliable records of what happened in the southern hemisphere during the Little Ice Age?

There is some evidence but not surprisingly contaversial.
Here's an interesting article hinting that Southern South America glaciers indicated growth rather than recession.
Little Ice Age in Southern South America? (from World Climate Report) (http://www.worldclimatereport.com/index.php/2008/04/21/little-ice-age-in-southern-south-america/)

The wikipedia article on LIA (http://en.wikipedia.org/wiki/Little_Ice_Age) indicates a number of lines of evidence
for example evidence from Sothern Africa ( core samples from Lake Malawi and a method using stalagmite growth) indicate reduced temperatures for the period 1500-1800.

Like a number of other postings in this thread if we are going into a prolonged solar minima then this might be an opportunity to understand more thoroughly the link between Solar Cycle and the Earths Climate.

tusenfem
2011-Jun-17, 07:36 AM
William, you are again pushing your unsubstantiated claims and continue to cite papers that have been rejected by mainstream scientists for good reasons.

Do you wish to continue this discussion, then I will reopen you ATM thread and move the last posts of this thread there.

ASTRONOMY is NOT the place to continue the discussion that was closed on your request because you had no answer to the questions put to you, apart from "we need more observations."

Keep on posting this stuff here, and you will receive an infraction.

Robert Tulip
2011-Jun-17, 09:44 AM
Could we be heading towards a new ice age?



Milankovitch orbital cycles, with observed correlation between northern hemisphere insolation and global glaciation patterns, suggest that we are now at a minimum after ten thousand years of slight global cooling, and the climate would be warming over the next ten thousand years, absent anthropogenic acceleration.

This is discussed at Insolation and Global Warming (http://www.bautforum.com/showthread.php/109120-Insolation-and-Global-Warming?highlight=insolation+and+global+warming)

jlhredshift
2011-Jun-17, 10:54 AM
Milankovitch orbital cycles, with observed correlation between northern hemisphere insolation and global glaciation patterns, suggest that we are now at a minimum after ten thousand years of slight global cooling, and the climate would be warming over the next ten thousand years, absent anthropogenic acceleration.

This is discussed at Insolation and Global Warming (http://www.bautforum.com/showthread.php/109120-Insolation-and-Global-Warming?highlight=insolation+and+global+warming)

Yet, NGRIP suggests 8000 years. I'm willing to accept your analysis of insolation, but is the difference an indication of a lag. Please see the chart from page 32 of:

Sea-level probability for the last deglaciation: a statistical analysis of
far-field records. J. D. Stanford et al. (http://www.soes.soton.ac.uk/staff/ejr/Rohling-papers/2010-highq%20file%20Stanford_et_al_2010_GPC.pdf)

jlhredshift
2011-Jun-17, 11:30 AM
http://scholar.google.com/url?sa=U&q=http://www.gg.rhbnc.ac.uk/elias/teaching/VanGeel.pdf

This link is broken.

jlhredshift
2011-Jun-17, 11:34 AM
The following paper from Reviews of Geophysics, 48, RG4001 / 2010 by Gray et al. is 53 pages and it will take me awhile to go through it, but I will post it in case somebody with a higher pay grade than me might comment:

SOLAR INFLUENCES ON CLIMATE (http://scostep.apps01.yorku.ca/wp-content/uploads/2010/07/Gray_etal_2009RG000282.pdf)

Robert Tulip
2011-Jun-17, 02:30 PM
Yet, NGRIP suggests 8000 years. I'm willing to accept your analysis of insolation, but is the difference an indication of a lag. Please see the chart from page 32 of:

Sea-level probability for the last deglaciation: a statistical analysis of
far-field records. J. D. Stanford et al. (http://www.soes.soton.ac.uk/staff/ejr/Rohling-papers/2010-highq%20file%20Stanford_et_al_2010_GPC.pdf)

Thanks JLH, good paper. You are right that temperature lags light. The long term temperature cycle seems to be rather like the annual cycle, where the coldest and hottest days in the northern hemisphere average one month after the shortest and longest days, as discussed at Daily Temperature Trend (http://www.bautforum.com/showthread.php/110725-Daily-Temperature-Trend?highlight=).
The time of highest insolation was about eleven thousand years ago when the June solstice was at perihelion. Similarly to the lag in the annual cycle, the hottest point, as shown at this Chart of Holocene Temperature Variations (http://upload.wikimedia.org/wikipedia/commons/c/ca/Holocene_Temperature_Variations.png), was several thousand years after the time of greatest northern summer light.

Tensor
2011-Jun-17, 09:33 PM
Tensor,

Attached is a more recent paper by Tinsley. The paper other paper you linked to discusses Jz's affect on the transparency of the atmosphere which is different than Jz's affect on planetary cloud cover.

Tinsley's research and analysis supports the assertion that GCR levels significantly affect planetary cloud cover and the electroscavenging mechanism.

And again, you obviously didn't read the paper:

The large changes in galactic cosmic ray flux on time scales from decades through millennia produce changes in Jz that have the potential to account for records of long-term climate variations that correlate with cosmic ray flux changes.

Note that he says have the potential, not that they actually do. How is it that you missed this part?


As noted above we do not need to argue. We can discuss observations and compare the observations to the predictions to determine which hypothesis is correct.

I have no problem discussing observations. In fact, a lot of observations you present are I have no problems and agree with. It's when you make unsupported comments, (such as the one about Tinsley's research and analysis when in fact, the statements within the paper contradict you), or take research and make comments that you want the paper to show, instead of what it does show, that I will object.

William
2011-Jun-18, 03:11 AM
And again, you obviously didn't read the paper:

The large changes in galactic cosmic ray flux on time scales from decades through millennia produce changes in Jz that have the potential to account for records of long-term climate variations that correlate with cosmic ray flux changes.

Note that he says have the potential, not that they actually do. How is it that you missed this part?

I have no problem discussing observations. In fact, a lot of observations you present are I have no problems and agree with. It's when you make unsupported comments, (such as the one about Tinsley's research and analysis when in fact, the statements within the paper contradict you), or take research and make comments that you want the paper to show, instead of what it does show, that I will object.

Hi Tensor,

I do not understand your comments. Perhaps if you quoted the specific section of Tinsley's paper I might understand how our view points differ. I am not sure what part of Tinsley's paper I missed.

Tinsley's paper is entitled "The role of the global electric circuit in solar and internal forcing of clouds and climate". Tinsley notes the global electric circuit has a significant forcing role of clouds and climate. That does not surprise me based on data and analysis in other published papers.

I see Svensmark just published his results which used CERN as a high energy source to test the assertion that GCR creates ions which via ion mediation results in a significant increase in planetary clouds. Svensmark's research supported that assertion.

Tinsley states the affect of variation of the global electric circuit on planetary clouds is 5% at low latitudes and 30% at higher latitudes. i.e. There is more cooling or warming due to increased or decreased GCR or solar wind bursts at higher latitudes.

I suppose most people are aware the majority of the 20th century warming was at high latitudes.

https://www.utdallas.edu/physics/faculty/tinsley/Role%20of%20Global%20Circuit.pdf


The role of the global electric circuit in solar and internal forcing of clouds and climate

The observed short-term meteorological responses to these five inputs are of small amplitude but high statistical significance for repeated Jz changes of order 5% for low latitudes increasing to 25–30% at high latitudes. On the timescales of multidecadal solar minima, such as the Maunder minimum, changes in tropospheric dynamics and climate related to Jz are also larger at high latitudes, and correlate with the lower energy component (_1 GeV) of the cosmic ray flux increasing by as much as a factor of two relative to present values.


Also, there are comparable cosmic ray flux changes and climate responses on millennial timescales. The persistence of the longer-term Jz changes for many decades to many centuries would produce an integrated effect on climate that could dominate over short-term weather and climate variations, and explain the observed correlations. Thus, we propose that mechanisms responding to Jz are a candidate for explanations of sun–weather–climate correlations on multidecadal to millenial timescales, as well as on the day-to-day timescales analyzed here.

I would assume everyone in the forum agrees the sun was at its highest activity level in 8000 years during the last 70 years of the 20th century and that it appears the sun is due to three different lines of research published by three separate solar specialist teams moving towards a Maunder Minimum.

As there has been a step change in the sun we can look for observational changes on the planet to validate or invalidate the different hypotheses.

As noted in published papers, an increase in GCR is alleged to cause an increase in heavy rainfall in addition to the cooling affect of increased cloud cover. We might therefore look for observation evidence of an increase in heavy rainfall and cooling to help validate the hypothesis. The validation will take sometime to ensure we are not confusing weather for climate change.

I am not sure what you or others in the forum believe is the mainstream view concerning the Little Ice Age and the Medieval warm period.

My paleoclimatic text books (Principles of Paleoclimatology by T. Cronin and Paleolclimatology Reconstructing the Climates of the Quaternary second Edition By R. Bradley) both show and discuss the Medieval warm period and Little Ice Age and have graphs in them that match figure 3 in this paper.

If you go to any University and check the Paleoclimatic textbooks they also will have a graph that matches figure 3.

When and why (scientifically) did figure 3 in this paper get revised? What is the new "mainstream" view of the paleoclimatic record for how planetary climate has changed in the last 12,000 years? (i.e. From the time of the Younger Dryas abrupt cooling period at 11,900 years ago and the 8,200 year ago abrupt cooling event to present.)

As I have noted the solar magnetic cycle changes cause changes to the amount of cosmogenic isotopes that are created in the upper atmosphere due to the solar heliosphere and solar winds modulating effect on Galactic Cosmic Radiation. The cosmogenic isotopes are deposited on the ice sheets and on the ocean floor. The cooling and warming on the earth correlates with cosmogenic isotope changes. The scientific question is why? i.e. What is the mechanism?

http://courses.washington.edu/pcc589/2009/readings/Dahl_Jensen.pdf


Past Temperatures Directly from the Greenland Ice Sheet

A Monte Carlo inverse method has been used on the temperature proÞles measured down through the Greenland Ice Core Project (GRIP) borehole, at the summit of the Greenland Ice Sheet, and the Dye 3 borehole 865 kilometers farther south. The result is a 50,000-year-long temperature history at GRIP and a 7000-year history at Dye 3. The Last Glacial Maximum, the Climatic Optimum, the Medieval Warmth, the Little Ice Age, and a warm period at 1930 A.D. are resolved from the GRIP reconstruction with the amplitudes Ð23 kelvin, 12.5 kelvin, 11 kelvin, Ð1 kelvin, and 10.5 kelvin, respectively. The Dye 3 temperature is similar to the GRIP history but has an amplitude 1.5 times larger, indicating higher climatic variability there.


Fig. 3. The contour plots of all the GRIP temperature histograms as a function of time describes the reconstructed temperature history (red curve) and its uncertainty. The temperature history is the history at the present elevation (3240 m) of the summit of the Greenland Ice Sheet (21). The white curves are the standard deviations of the reconstruction (18). The present temperature is shown as a horizontal blue curve. The vertical colored bars mark the selected times for which the temperature stograms are shown in Fig. 2. (A) The last 100 ky BP. The LGM (25 ka) is seen to have been 23 K colder than the present temperature, and the temperatures are seen to rise directly into the warm CO 8 to 5 ka. (B) The last 10 ky BP. The CO is 2.5 K warmer than the present temperature, and at 5 ka the temperature slowly cools toward the cold temperatures found around 2 ka. (C) The last 2000 years. The medieval warming (1000 A.D.) is 1 K warmer than the present temperature, and the LIA is seen to have two minimums at 1500 and 1850 A.D. The LIA is followed by a temperature rise culminating around 1930 A.D. Temperature cools between 1940 and 1995.

Tensor
2011-Jun-18, 03:55 AM
Hi Tensor,

I do not understand your comments. Perhaps if you quoted the specific section of Tinsley's paper I might understand how our view points differ. I am not sure what part of Tinsley's paper I missed.

I'm not sure why there is any confusion. It's a direct quote from the conclusion section of the paper you provided. Again, if you read the paper, how is it that you missed the part that repudiated your claim of what the paper claimed?


Tinsley's paper is entitled

snip....

I see Svensmark just published his results which used CERN as a high energy source to test the assertion that GCR creates ions which via ion mediation results in a significant increase in planetary clouds. Svensmark's research supported that assertion.

I'll answer this one. Svensmark published results which used CERN to show that GCRs can create ions. I seriously doubt that his use of CERN as a high energy source resulted in even a small, much less a significant, increase in planetary clouds.

As for the rest, it has nothing to do with the title of this thread. If you had wanted to discuss the rest of this, why did YOU request the ATM thread on your ideas be closed, with all those unanswered questions YOU left hanging?

Swift
2011-Jun-18, 04:49 AM
<snip>
I see Svensmark just published his results which used CERN as a high energy source to test the assertion that GCR creates ions which via ion mediation results in a significant increase in planetary clouds. Svensmark's research supported that assertion.

Tinsley states the affect of variation of the global electric circuit on planetary clouds is 5% at low latitudes and 30% at higher latitudes. i.e. There is more cooling or warming due to increased or decreased GCR or solar wind bursts at higher latitudes.

I suppose most people are aware the majority of the 20th century warming was at high latitudes.


As there has been a step change in the sun we can look for observational changes on the planet to validate or invalidate the different hypotheses.

William,

The intent of this thread would seem to be to discuss whether there has in fact been a "step change in the sun". It seems far from proven that this is the case. But this is most certainly not another thread to discuss your ideas of the supposed connections between solar activity and global warming. The use of climate change as evidence of changes in the sun seems dubious at best and ATM at worst. In any case, you have had multiple threads and opportunities to discuss your ideas on this and I do not want to see yet another thread on solar activity turned into your private stage for such discussions.

If you wish to discuss your ideas on weather/climate and solar activity, ask for your ATM thread to be reopened or start a new thread. Let's leave this thread purely for the discussion topic started by elizabeth25

Trakar
2011-Jun-18, 06:15 AM
The following paper from Reviews of Geophysics, 48, RG4001 / 2010 by Gray et al. is 53 pages and it will take me awhile to go through it, but I will post it in case somebody with a higher pay grade than me might comment:

SOLAR INFLUENCES ON CLIMATE (http://scostep.apps01.yorku.ca/wp-content/uploads/2010/07/Gray_etal_2009RG000282.pdf)


Interesting paper and research with lots of application to the OP

The Stanford Solar Center discusses it in passing on their global warming page (http://solar-center.stanford.edu/sun-on-earth/glob-warm.html), but it is a fairly easy and informative read, and especially with respect to this threads topic I'd encourage those interested to actually wade into the paper (http://solar-center.stanford.edu/sun-on-earth/2009RG000282.pdf)itself.

William
2011-Jun-18, 11:56 AM
It does appear there has been a step change in the sun (See solar cycle 24 for details.) It will likely take a couple of years to confirm that.

http://www.bautforum.com/showthread.php/68781-Solar-cycle-24?p=1901338#post1901338

Trakar
2011-Jun-18, 05:24 PM
It does appear there has been a step change in the sun (See solar cycle 24 for details.) It will likely take a couple of years to confirm that.

http://www.bautforum.com/showthread.php/68781-Solar-cycle-24?p=1901338#post1901338

On the effect of a new grand minimum of solar activity on the future climate on Earth - http://www.agu.org/pubs/crossref/2010/2010GL042710.shtml

(full paper available at: http://www.pik-potsdam.de/~stefan/Publications/Journals/feulner_rahmstorf_2010.pdf )


...In summary, global mean temperatures in the year 2100 would most likely be diminished by about 0.1°C. Even
taking into account all uncertainties in the temperature reconstruction, the forcings, and the model physics, the overall uncertainty is estimated to be at most a factor of 3, so the offset should not be larger than 0.3°C. Comparing this to the 3.7°C and 4.5°C temperature rise relative to 1961–1990 until the end of the century under the IPCC A1B and A2 emission scenarios, respectively, a new Maunder‐type solar activity minimum cannot offset the global warming caused by human greenhouse gas emissions. Moreover, any offset of global warming due to a grand minimum of solar activity would be merely a temporary effect, since the distinct solar minima during the last millennium typically lasted for only several decades or a century at most.

Regardless of any interest some may or may not share with respect to AGW, the paper above on grand minimum analysis should go a long ways toward providing some answers to questions concerning how it will impact us if such occurs in the near future.