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

[Saul]

Something that I found interesting (see papers below) is the inverse relationship of sunspot number and volcanic eruptions. During Maunder and Dalton minimums there are significantly more and larger volcanic eruptions. When the sunspot activity is high there is less volcanic activity.

There is also correlation with earthquakes, however, the paleo earthquake data is difficult to data so the relationship has only been shown for human record history.

The paper at the end of this comment notes the volcanic eruptions are following a millennium periodicity. The paper provided above notes that geomagnetic field intensity also varies with a millennium periodicity.

The paper linked to above showed a set of volcanoes that do not share the same magna chamber yet that erupted within a sort period of time together and that all recorded a geomagnetic excursion when the lava cooled. This finding shows a link between what is causing the geomagnetic field excurion and what is causing a simultaneous volcanic eruption from a set of volcanoes that do not share the same magna chamber.

What it appears is happening is the solar magnetic cycle is interrupted and when it restarts there are very large coronal mass ejections. The CME create a space charge differential in the ionosphere which then creates a potential difference between the planet and the earth. There is a strike from the planet to the Earth which disrupts the geomagnetic field. Depending on the hemisphere where the strike is the geomagnetic field is either strengthened or weakened.

As the core magnetic field time constant is around 3000 years, initially the strike always weakens the geomagnetic field in the region of the strike.

In paleo past the super volcanic eruptions have also correlate with deep solar minimums.

http://adsabs.harvard.edu/abs/1989JGR...9417371S

“Volcanic eruptions and solar activity” by Richard Stothers

The historical record of large volcanic eruptions from 1500 to 1980 is subjected to detailed time series analysis. In two weak but probably statistically significant periodicities of about 11 and 80 yr, the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). Time series analysis of the volcanogenic acidities in a deep ice core from Greenland reveals several very long periods ranging from about 80 to about 350 yr which are similar to the very slow solar cycles previously detected in auroral and C-14 records. Solar flares may cause changes in atmospheric circulation patterns that abruptly alter the Earth's spin. The resulting jolt probably triggers small earthquakes which affect volcanism. (My comment. This mechanism guess is not correct.)

http://adsabs.harvard.edu/abs/2002AGUFMPP61A0298A

The Role of Explosive Volcanism During the Cool Maunder Minimum

The Dalton Minimum was a period of low solar activity, named for the English meteorologist John Dalton, lasting from about 1790 to 1830.[1] Like the Maunder Minimum and Spörer Minimum, the Dalton Minimum coincided with a period of lower-than-average global temperatures. The Oberlach Station in Germany, for example, experienced a 2.0° C decline over 20 years.[2] The Year Without a Summer, in 1816, also occurred during the Dalton Minimum. The precise cause of the lower-than-average temperatures during this period is not well understood. Recent papers have suggested that a rise in volcanism was largely responsible for the cooling trend.[3]

http://www.pnas.org/content/101/17/6341.full#otherarticles

Analyzing data from our optical dust logger, we find that volcanic ash layers from the Siple Dome (Antarctica) borehole are simultaneous (with >99% rejection of the null hypothesis) with the onset of millennium-timescale cooling recorded at Greenland Ice Sheet Project 2 (GISP2; Greenland). These data are the best evidence yet for a causal connection between volcanism and millennial climate change and lead to possibilities of a direct causal relationship. Evidence has been accumulating for decades that volcanic eruptions can perturb climate and possibly affect it on long timescales and that volcanism may respond to climate change. If rapid climate change can induce volcanism, this result could be further evidence of a southern-lead North–South climate asynchrony. Alternatively, a volcanic-forcing viewpoint is of particular interest because of the high correlation and relative timing of the events, and it may involve a scenario in which volcanic ash and sulfate abruptly increase the soluble iron in large surface areas of the nutrient-limited Southern Ocean, stimulate growth of phytoplankton, which enhance volcanic effects on planetary albedo and the global carbon cycle, and trigger northern millennial cooling. Large global temperature swings could be limited by feedback within the volcano–climate system.

 

[Saul]

The papers in the above comment show there is correlation with solar magnetic minimums with volcanic activity.

This is the paper that provides evidence of multiple volcanoes with different magma chambers all erupting in a short time period and all capturing a geomagnetic excursion.

http://www.agu.org/pubs/crossref/2006/2006GL027284.shtml

Geomagnetic excursion captured by multiple volcanoes in a monogenetic field

Five monogenetic volcanoes within the Quaternary Auckland volcanic field are shown to have recorded a virtually identical but anomalous paleomagnetic direction (mean inclination and declination of 61.7° and 351.0°, respectively), consistent with the capture of a geomagnetic excursion. Based on documented rates of change of paleomagnetic field direction during excursions this implies that the volcanoes may have all formed within a period of only 50–100 years or less. These temporally linked volcanoes are widespread throughout the field and appear not to be structurally related. However, the general paradigm for the reawakening of monogenetic fields is that only a single new volcano or group of closely spaced vents is created, typically at intervals of several hundred years or more. Therefore, the results presented show that for any monogenetic field the impact of renewed eruptive activity may be significantly under-estimated, especially for potentially affected population centres and the siting of sensitive facilities.

 

[Saul]

This is an interesting discussion concerning "Courtillot et al's paper: Are there connections between the Earth's magnetic field and climate?"

The geomagnetic data indicates that something is forcing the geomagnetic field changing the tilt of the geomagnetic field in relationship with the Earth's axis of rotation as well as modulating the intensity of the geomagnetic field. As the planet's core is conductive, currents are induced in the conductive core which work to return symmetry of the geomagnetic field and the Earth's axis of rotation.

The geomagnetic field deflects galactic cosmic radiation (GCR). With strongest GCR deflection at 90 degrees to the magnetic field poles and the weakest GCR deflection at the magnetic poles.

Tilting the geomagnetic field and the creation of large geomagnetic field anomalies brings the magnetic pole down to lower latitudes where there is warmer moist air. GCR has been shown to increase planetary cover and increase rainfall. The increase in planetary cloud cover cools the planet.

The discussion explains both the mechanism and the periodicity of the forcing event. The forcing events vary in magnitude and correlate with solar magnetic cycle minimums. It appears the forcing event is related to the restart of the solar magnetic field mechanism. The paleoclimatic shows immediate cooling when the solar magnetic cycle is interrupted which creates a weak solar heliosphere. (The solar heliosphere also deflects GCR.)

Then when the solar magnetic cycle restarts there is this sudden geomagnetic forcing event that tilts the geomagnetic field and creates a geomagnetic field anomaly which is a region of stronger or weaker field. Whether the forcing event constructively or de-constructively reinforces the geomagnetic field depends on the orientation of the geomagnetic field at the time of event and the hemisphere where the strike occurs.

There is correlation of geomagnetic field intensity with both the amount of tilt of the planet and with eccentricity of the planet's orbit. So if you can imagine the strike event which is controlled by a solar process, its affect on the geomagnetic field depends on the Earth sun distance (orbital eccentricity) and tilt of the planet.

The time constant of the geomagnetic field is 1000s of years, so the affects of a significant geomagnetic field forcing change can persist as opposed to the solar magnetic cycle minimum which is less than 100 years.

The paleoclimatic data shows evidence of multiple forcing events with varying magnitudes of temperature changes. The strongest events are called Henrich events which have a periodicity of 6000 years to 8000 years. There is also a strong cycle with a periodicity of the 1470 years. There is correlation of cosmogenic isotope changes with both the 1470 cycle and the Henrich events.

http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf

Also, we wish to recall that evidence of a correlation between archeomagnetic jerks and cooling events (in a region extending from the eastern North Atlantic to the Middle East) now covers a period of 5 millenia and involves 10 events (see f.i. Figure 1 of Gallet and Genevey, 2007). The climatic record uses a combination of results from Bond et al (2001), history of Swiss glaciers (Holzhauser et al, 2005) and historical accounts reviewed by Le Roy Ladurie (2004). Recent high-resolution paleomagnetic records (e.g. Snowball and Sandgren, 2004; St-Onge et al., 2003) and global geomagnetic field modeling (Korte and Constable, 2006) support the idea that part of the centennial-scale fluctuations in 14C production may have been influenced by previously unmodeled rapid dipole field variations. In any case, the relationship between climate, the Sun and the geomagnetic field could be more complex than previously imagined. And the previous points allow the possibility for some connection between the geomagnetic field and climate over these time scales.

Point 4: We first reiterate the fact that the “claims” made in our paper regarding correlations between cooling periods and archeomagnetic jerks were actually put forward by Gallet et al (2005, 2006). We do note that the causal relationship between cosmic ray flux and cloud cover suggested by Marsh and Svensmark (2000) would result in a correlation opposite to the one we find if the field geometry were axial and dipolar and this is precisely why we propose a mechanism of dipole tilt or non dipole geometry to interpret our observations. Gallet et al (2005) write: “ Another hypothesis is to assume that the incoming charged particles are deflected towards the poles, where the overall low humidity level due to cold temperatures limits cloud formation. If archeomagnetic jerks indeed correspond to periods of strongly inclined dipole, then the charged particles would interact with more humid air from lower latitude environments, leading to significantly larger cloud production and cooling.” And if this happens, there is no need to “overcome the more direct effect", as (mis)understood by BD07 (who seem to understand that a growing axial dipole is superimposed on a tilted dipole, which is not the case).

It is therefore not surprising that the tuned curve should reveal the link between solar activity and O18. It is moreover interesting to note that this correlation, obtained on an Alpine stalagmite, and therefore evidence of the influence of solar variability on climate, is also found in proxies from other regions around the globe: correlation between times of solar minima and cold episodes in western Europe (Magny, 1993; Holzhauser et al, 2005), modulation of precipitation in the tropics in Northern South America and Yucatan (Haug et al, 2001), in Eastern Africa (Verschuren et al, 2000), and Arabia (Neff et al, 2001); influence on droughts in North America (Yu and Ito, 1999).

This is a link to the original paper.

Are there connections between the Earth's magnetic field and climate?

http://sciences.blogs.liberation.fr/home/files/Courtillot07EPSL.pdf

 

[Xnn]

About this paper:

It suggests that solar irradiance could have been a major forcing function of climate until the mid-1980s, when “anomalous” warming becomes apparent.

So, only greenhouse gases can explain the warming of the last 25 years.

 

[mheslep]

About this paper:

So, only greenhouse gases can explain the warming of the last 25 years.

That does not logically follow from the statement in the Courtillot et al abstract you quoted.

 

[Xnn]

There has been a lot of warming over the last 25 years.
However, the paper does not come up with a solar explanation for it.

We know that greenhouse gases have been rising steadily for over a hundred years.
Initially, the influence of rising greenhouse gases were small compared to short term fluctuations such as those from solar changes. However, over time, the influence of greenhouse gases have accumulated and are now dominating climate change. Short term fluctuations still exist, but the overall warming trend is unmistakable.

Solar influences are at nearly a 100 year minimum and should be leading to significant global cooling. However, the last 2 months have both been the 2nd warmest months (September & October) since 1880. So, again we see that solar theories cannot explain current climate change.

I'm open minded about solar theories, but nothing in this thread has shown that they could reasonably be used to dismiss the influence of greenhouse gases.

 

[seycyrus]

Are you guys aware that the American Physical Society is now emailing its members to see how they feel about their official statement regarding AGW, and a proposed revised statement offered by some of its fellows?

 

[Xnn]

No, but if this is the "Official" statement, then I can see why.
IMO, it's a stretch to state that security and human health will be impacted by climate change more so than from routine population increases or all the wars that we have.

Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate. Greenhouse gases include carbon dioxide as well as methane, nitrous oxide and other gases. They are emitted from fossil fuel combustion and a range of industrial and agricultural processes.

The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.

Because the complexity of the climate makes accurate prediction difficult, the APS urges an enhanced effort to understand the effects of human activity on the Earth’s climate, and to provide the technological options for meeting the climate challenge in the near and longer terms. The APS also urges governments, universities, national laboratories and its membership to support policies and actions that will reduce the emission of greenhouse gases.

 

[Wagmc]

So, only greenhouse gases can explain the warming of the last 25 years.

TSI is not the only component of solar forcing. You continue to ignore indirect (magnetic) effects as well as the recent discovery that UV modulates ozone production over the poles, which is an exothermic reaction.


http://www.iop.org/EJ/abstract/0004-637X/705/1/926/"

New study confirms that solar magnetic activity drives the solar wind, which, if Svensmark is correct (and we'll soon know) modulates cloud cover and Earth temperatures.

And solar magnetic activity continues to decline even as cycle 24 ramps up.
http://www.swpc.noaa.gov/ftpdir/weekly/RecentIndices.txt"

 

[Xnn]

I'm not ignoring the other components of solar forcing. UV modulation of ozone does impress me as a plausable mechanism. However, I haven't see a peer reviewed paper that quantifies it or an paper that quantifies any solar mechanism for the last 25 years of warming.

We are also about 2 years into the most significant solar minimum since 1912, and yet global temperatures are very near all time instrumented highs.

 

[Saul]

A significant portion of the 20th century warming is hypothesized to be caused by solar wind bursts. Solar wind bursts remove cloud forming ions and hence makes it appear increases in GCR does not cause an increase in planetary cloud cover.

The solar wind bursts were created by coronal holes that moved down to lower latitudes of the sun late in the cycle of cycles 22 and cycle 23. As noted below, although cycle 24 appears to be a rump or abrupt Maunder minimum, there are three times as many solar wind bursts being produced.

Solar wind bursts remove cloud forming ions by a process that is called "electroscavenging".
This paper explains how GCR and solar magnetic cycle changes are hypothesized to change planetary climate.

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

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

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

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

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.

If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals (Cycle 24 and Cycle 23/22)

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.

 

[Wagmc]

I haven't see a peer reviewed paper that quantifies it or an paper that quantifies any solar mechanism for the last 25 years of warming

I'll post you some references. There are several.

We are also about 2 years into the most significant solar minimum since 1912, and yet global temperatures are very near all time instrumented highs.

Only if you look at the contaminated surface record. Satellites don't show that "all time" high.

As for "where's the cooling?" Ha. Where's the warming? If CO2 is such a significant driver of temps, they why no warming since 2000?

This is a water planet. Lots of studies put the solar lag at 5 to 15 years due to the huge ocean sinks. Even as we speak a little el nino is transferring heat to air, where it will be convected away. The planet is cooling.

 

[mheslep]

I'll post you some references. There are several.



Only if you look at the contaminated surface record. Satellites don't show that "all time" high.

1998 aside, sure they do, at least over the three decades of satellite records.
http://upload.wikimedia.org/wikipedia/commons/7/7e/Satellite_Temperatures.png

 

[Saul]

I'm not ignoring the other components of solar forcing. UV modulation of ozone does impress me as a plausable mechanism. However, I haven't see a peer reviewed paper that quantifies it or an paper that quantifies any solar mechanism for the last 25 years of warming.

We are also about 2 years into the most significant solar minimum since 1912, and yet global temperatures are very near all time instrumented highs.

Yes, however, as noted solar wind bursts continue to be produced by the sun even though the solar magnetic cycle is at a 100 year minimum.

(See Paper: If the Sun is so quiet, why is the Earth ringing? A comparison of two solar minimum intervals (Cycle 24 and Cycle 23/22)).

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

The solar wind bursts remove cloud forming ions by the process of electroscavenging which results in a decrease in low level clouds and an increase in high level clouds. See Tinsley's paper below.

The solar wind bursts are starting to abate. Based on the mechanisms what should be observed now is an increase in low level clouds and a decrease in high level clouds due to the increased GCR, at latitudes from 40 degree to 60 degree both hemispheres.

The decrease in high level clouds will result in exceptionally cold nights in the higher latitude regions which should result in increased sea ice both hemispheres.

In addition as the global electric circuit will be reduced it is expect that there will be increased cloud cover in the tropics.

The cooling will be moderate by the El Nino event, so the full effect of the cooling may not be expected until the winter of 2010/2011.

http://upload.wikimedia.org/wikipedia/commons/7/7e/Satellite_Temperatures.png

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

4b. Altitude and solar cycle dependencies

Ambient ions are continuously generated by galactic cosmic rays as noted earlier, with the magnitude of the ionization rate variations being a function of latitude and altitude. During a solar cycle, the values of Q vary by ~ 20 -25% in the upper troposphere and ~5-10% in the lower troposphere for high latitudes, and by ~4-7% in the upper troposphere and ~3-5% in the lower troposphere for low latitudes [Ney, 1959]. The effect of such systematic change in ionization rate on the altitude profile for the production of ultrafine particles has been studied by Yu [2002].

Figure 4.2 shows the total condensation nuclei bigger than 3nm (Nd>3 nm) after three hours of simulations at different altitudes. The line with open circles is for the baseline Q values while the line with filled circles is for Q values 20% over the corresponding baseline values. ….The neutralization by ion-ion recombination will make the growing charged clusters lose their growth advantage and the resulting neutral clusters may dissociate if smaller than the critical size. At typical [H2SO4] where significant nucleation has been observed, for very low Q most of the ion clusters have sufficient time to reach the larger stable sizes prior to recombination and the nucleation rate is limited by Q. As Q (or altitude) increases, ion concentration increases but the lifetime of ions decreases and hence the fraction of ions having sufficient time to grow to the stable sizes decreases. As a result, the total number of particles nucleated first increases rapidly but later on decreases as Q (or altitude) increases. The altitude of the turning point is around 4 km under the vertical profiles assumed in this study.

It is clear from Figure 4.2 that an increase in GCR ionization rate associated with solar activity leads to an increase in the ultrafine production rate (i.e., dN/dQ > 0) in the lower troposphere (as indicated by the arrows) but a decrease in the ultrafine production rate (i.e., dN/dQ < 0) in the upper troposphere (as indicated by the arrows). In the middle troposphere, dN/dQ changes sign and the average value of dN/dQ is small compared to that of lower and upper troposphere.

5. The Global Electric Circuit and Electroscavenging

5a. Modulation of Jz in the global circuit.

The global electric circuit was illustrated pictorially in Figure 3.1, and a schematic circuit diagram is given in Figure 5.1. General properties of the circuit have been reviewed by Bering et al. [1998[. Earlier comprehensive reviews have been given by NAS [1986] and Israël [1973]. The polar potential pattern is superimposed on the thunderstorm-generated potentials. In a given high latitude region the overhead ionospheric potential, Vi is the sum of the thunderstorm-generated potential and the superimposed magnetosphere-ionosphere generated potential for that geomagnetic latitude and geomagnetic local time. During magnetic storms the changes in Vi from the mean can be as high as 30% within regions extending up to 30km of latitude out from the geomagnetic poles [Tinsley et al.1998].

As indicated in Figure 5.1, horizontal potential differences of order 100 kV are generated, high on the dawn side and low on the dusk side, producing corresponding changes in Vi and Jz. The dawn-dusk potential difference has a strong dependency on the product of the solar wind velocity, vsw, and the Bz(GSM) north-south solar wind magnetic field component [Boyle et al., 1997].

 

[mheslep]

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

All else remaining the same, i.e., ONLY if all other forcings were to remain a net constant, which they never do.

 

[Wagmc]

1998 aside, sure they do, at least over the three decades of satellite records.

Uhm...no. I see a plateau since 2000, and the most recent temps are NOT record highs.

Just because you read it in the news does not make it a fact.

This was in response to the statement:

We are also about 2 years into the most significant solar minimum since 1912, and yet global temperatures are very near all time instrumented highs.

your lovely chart makes my point nicely, although the clever use of scaling makes temps looks like...uhm...a hokey stick. Here's another view direct from UAH that puts it in a little better perspective.

http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_Oct_09.jpg

I'm still seeing a plateau after 2000. No record-breaking warming in the last two years. This in spite of continuing increases in CO2, but I digress...

 

[mheslep]

Uhm...no. I see a plateau since 2000, and the most recent temps are NOT record highs.

Just because you read it in the news does not make it a fact.

[...]
your lovely chart

Its not mine.

makes my point nicely, although the clever use of scaling makes temps looks like...uhm...a hokey stick.

The attitude doesn't help. Please check it at the door.

Here's another view direct from UAH that puts it in a little better perspective.

http://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_Oct_09.jpg

Same data. So what?

I'm still seeing a plateau after 2000.

Yes temperatures are at plateau for the last few years. A HIGH plateau.

No record-breaking warming in the last two years.

So? The statement was "temperatures are very near all time instrumented highs."Indeed they are. Nobody said new records. Please don't attribute that which was not said. A plateau maintains the highs.

 

[Xnn]

https://www.physicsforums.com/attachment.php?attachmentid=21606&stc=1&d=1257469597

The above image of Arctic temperatures over the last 2000 years is based on a very recent study.

Observe that over the fist 1900 years, there were indeed several ~100 year long periods of
warming and cooling that might be attributed to changes in solar forcing. There is also a
clear overall cooling trend attributed to changes in Earth's orbit (gradually lowering of solar
insolation at 65N; AKA Milankovitch theory).

If one looks closely, the Maunder Minimum (1645 to 1715) is discernible. There is also the
Dalton Minimum (1790 to 1815), but I can't clearly pick it out in the temperature record.
However, what really sticks out is that there really are no good solar theories that can
explain the last 100 years and especially the last 25 years of warming.

I'm trying to be open minded here!The source document is found at the following:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

 

[Saul]

The above image of Arctic temperatures over the last 2000 years is based on a very recent study.

Observe that over the fist 1900 years, there were indeed several ~100 year long periods of
warming and cooling that might be attributed to changes in solar forcing. There is also a
clear overall cooling trend attributed to changes in Earth's orbit (gradually lowering of solar
insolation at 65N; AKA Milankovitch theory).

If one looks closely, the Maunder Minimum (1645 to 1715) is discernible. There is also the
Dalton Minimum (1790 to 1815), but I can't clearly pick it out in the temperature record.
However, what really sticks out is that there really are no good solar theories that can
explain the last 100 years and especially the last 25 years of warming.

I'm trying to be open minded here!

The source document is found at the following:

http://www.ucar.edu/news/releases/2009/arctic2k.jsp

Xnn,
How did planetary temperature or temperature in the Northern Hemisphere change during the same period?

Why do you believe that graph corresponds to actual arctic temperatures. What proxy did the authors use to determine arctic temperatures for the period?

 

[Saul]

If the GCR theory is correct, then the planet must start to cool, as GCR is 19% higher than past periods and the solar wind bursts are starting to abate.

There is starting to be some observational evidence that the planet is cooling such as the coldest US October in 110 years and the coldest New Zealand October in 45 years. When the current El Nina dissipates perhaps there will be more observational evidence. November appears to be warmer, however, the warmer November is likely El Nina.

A significant portion of the 20th century warming is hypothesized to be due to solar wind bursts removing cloud forming ions by the process called "electroscavenging". Even though GCR is high if the solar wind bursts remove the cloud forming ions then the affects of GCR will not be observed.

Planetary temperature is closed correlated with the parameter Ak which is a measure of the solar wind and solar wind bursts. (See my comments above for links to papers.)


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 (Solar Cycle 24 compared to past solar cycles.)

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. In response, geospace and upper atmospheric parameters continued to ring with the periodicities of the solar wind in a manner that was absent last cycle minimum, and the flux of relativistic electrons in the Earth's outer radiation belt was elevated to levels more than three times higher in WHI than in WSM.

 

[mheslep]

If the GCR theory is correct, then the planet must start to cool, as GCR is 19% higher than past periods and the solar wind bursts are starting to abate.

Saul, for that statement to hold, you'd have to show, at a minimum, what fraction GCR contributes to planetary energy budget. I have no idea, but if its impact is, say, 5% of albeto based radiation return to space then a 200% increase in GCR won't mean the planet as a whole will 'start to cool'.

There is starting to be some observational evidence that the planet is cooling such as the coldest US October in 110 years and the coldest New Zealand October in 45 years. When the current El Nina dissipates perhaps there will be more observational evidence. November appears to be warmer, however, the warmer November is likely El Nina.

What's the point of saying, aha, there's some cooling (or warming) at some localized point on the planet, in isolation from the rest of planet?

 

[Saul]

Saul, for that statement to hold, you'd have to show, at a minimum, what fraction GCR contributes to planetary energy budget. I have no idea, but if its impact is, say, 5% of albeto based radiation return to space then a 200% increase in GCR won't mean the planet as a whole will 'start to cool'.

What's the point of saying, aha, there's some cooling (or warming) at some localized point on the planet, in isolation from the rest of planet?

mheslep,
Based on the mechanisms and past cooling events the planet will overcome the current El Nina and start cooling this winter. The cooling will continue reaching the new equilibrium low in about 5 years.

The cloud data indicates as much as 75% of the planet's 20th century warming was due to solar wind bursts that created a space charge in the ionosphere that removed ions from the atmosphere by the mechanism that is called electroscavenging which resulted in less clouds which caused the planet to warm.

Electroscavenging was stopped (coronal holes are starting dissipate), the solar heliosphere is at its lowest level in almost 50 years, GCR has increased by 19% and based on past solar magnetic deep minimums, GCR will increase to around 30%.

So as there is both a cessation of electroscavenging and an increase in GCR there will be an increase in low level planetary cloud cover which will cause increase planetary low level planetary cloud cover and cooling.

Higher GCR also causes a reduction in high level cloud cover. High level clouds warm the planet particularly at high latitudes in the winter.

The net result will be record cold winter temperatures at high latitudes and more clouds over the oceans as the atmosphere over the oceans is ion poor.

The geomagnetic changes later, perhaps a number of decades later based on the paleoclimatic record.

I am saying the planet has in the past abruptly cooled when the sun went into a deep solar minimum. I have provided a series of paper that show there are abrupt changes to the geomagnetic field inclination and magnitude that correlate with the abrupt cooling event. The hypothesized mechanism is the sun goes into a deep solar magnetic cycle minimum. When the sun restarts there are a series of massive coronal mass ejections which create a space charge differential in the ionosphere which cause a flash over from the ionosphere to the planet's surface.

The paper copied above shows evidence of 10 such events in the last 10,000 years. Geomagnetic specialists have coined the term archomagnetic jerks for the observations.

The paper I linked to above shows 5 New Zealand volcanoes that do not share the same magma chamber that suddenly erupted within a period of 100 years and that all capture in their magma flow evidence of a geomagnetic field direction excursion that occurs with in the period.http://www.esd.ornl.gov/projects/qen/transit.html


Sudden climate transitions during the Quaternary

Until a few decades ago it was generally thought that all large-scale global and regional climate changes occurred gradually over a timescale of many centuries or millennia, scarcely perceptible during a human lifetime. The tendency of climate to change relatively suddenly has been one of the most suprising outcomes of the study of Earth history, specifically the last 150,000 years (e.g., Taylor et al., 1993). Some and possibly most large climate changes (involving, for example, a regional change in mean annual temperature of several degrees celsius) occurred at most on a timescale of a few centuries, sometimes decades, and perhaps even just a few years. The decadal-timescale transitions would presumably have been quite noticeable to humans living at such times,

Initial evidence from the GRIP ice core evidence (Dansgaard et al., 1993; Taylor et al. 1993) indicated that the Eemian (My comment last interglacial period) was punctuated by many short-lived cold events, as shown by variations in electrical conductivity (a proxy for windblown dust, with more dust indicating colder, more arid conditions) and stable oxygen isotopes (a proxy for air temperature) of the ice were used by these workers infer the climatic conditions during the Eemian. The cold events seemed to last a few thousand years, and the magnitude of cooling was similar to the difference between glacial and interglacial conditions; a very dramatic contrast in climate. Furthermore, the shifts between these warm and cold periods seemed to be extremely rapid, possibly occurring over a few decades or less.

http://www.geo.arizona.edu/palynology/geos462/8200yrevent.html

The 8200 B.P. event, "lasted four hundred years (6400-6000 B.C.) and, like the Younger Dryas, generated abrupt aridification and cooling in the North Atlantic and North America, Africa, and Asia (Alley et al. 1997; Barber et al. 1999; Hu et al. 1999; Street-Perrot and Perrot 1990). This event is well-known from the GISP2 analyses, within which it is second only to the Younger Dryas in magnitude of some measurable variables (Alley et al. 1997; Figure 22). The pronounced West Asian signal for the 8200 B.P. event is present in Soreq Cave speleothem records (Bar-Matthews et al. 1999), Negev snail isotope variability (Goodfriend 1991, 1999), low Dead Sea levels (Frumkin et al. 1994), and the geochemistry of stage E to stage F transition at Lake Van (Lemcke and Sturm 1997). . .

."

 

[mheslep]

The cloud data indicates as much as 75% of the planet's 20th century warming was due to solar wind bursts that created a space charge in the ionosphere that removed ions from the atmosphere by the mechanism that is called electroscavenging which resulted in less clouds which caused the planet to warm.

Okay, sorry, what cloud data? I've missed the link.

I am saying the planet has in the past abruptly cooled when the sun went into a deep solar minimum. I have provided a series of paper that show there are abrupt changes to the geomagnetic field inclination and magnitude that correlate with the abrupt cooling event. The hypothesized mechanism is the sun goes into a deep solar magnetic cycle minimum. When the sun restarts there are a series of massive coronal mass ejections which create a space charge differential in the ionosphere which cause a flash over from the ionosphere to the planet's surface.

Okay, but the Adams-Maslin-Thomas paper you referenced proposes no hard connection with these changes. It widely discusses, or even simply muses about, only possibilities as I read it, of a dozen different long term climate effects.

 

[Xnn]

Data currently available for the Southern Hemisphere is too sparse to allow for construction of a temperature timeline with similar resolution to that in message #138.

https://www.physicsforums.com/showpost.php?p=2429570&postcount=138

Notice that the graph in message #138 is one of the newest reconstructions with much higher resolution than previously found for the Arctic. It's based on sediments in lakes.
What's remarkable about the graph is that one can pick out a cooling period concident with the Maunder Minimum. So, sunspots and solar changes related to sunspots probably did have a noticeable influcence global temperatures. However, due to their cyclic nature, we can't say that they drove climate over periods greater than ~100 years.

What has happened over the last century in the Arctic is unprecidented over the last 2000 years. The chances of it being caused by changes in sunspots, solar winds, UV spectrum shifts, cosmic rays and everything related is zilch.

Prior to 1910, solar and orbital changes were driving the climate over ~100 years time scales with El Nino/La Nina over time scales of <10 years. Since about 1950, changes in greenhouse gases are dominating climate change. Solar and orbital changes still exist and play a role, but are probably about an order of magnitude smaller than those from greenhouse gases.