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WestBabylonWeather

Grand Solar Minimum

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1 hour ago, etudiant said:

Separately, the volcanic impact on the LIA remains uncertain. My impression is there were no huge eruptions in the 1600s or the early 1700s, so the LIA cold is hard to blame on volcanoes.

Volcanism may have been the trigger leading to more extensive Arctic sea ice coverage. This would make sense since the cooling began several centuries before the solar minimum.

Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea‐ice/ocean feedbacks

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL050168

16] Our precisely dated records demonstrate that the expansion of ice caps after Medieval times was initiated by an abrupt and persistent snowline depression late in the 13th Century, and amplified in the mid 15th Century, coincident with episodes of repeated explosive volcanism centuries before the widely cited Maunder sunspot minimum (1645–1715 AD [Eddy, 1976]). Together with climate modeling and supported by other proxy climate reconstructions, our results suggest that repeated explosive volcanism at a time when Earth's orbital configuration resulted in low summer insolation across the NH acted as a climate trigger, allowing Arctic Ocean sea ice to expand. Increased sea ice export may have engaged a self‐sustaining sea‐ice/ocean feedback unique to the northern North Atlantic region that maintained suppressed summer air temperatures for centuries after volcanic aerosols were removed from the atmosphere. The coincidence of repeated explosive volcanism with centuries of lower‐than‐modern solar irradiance (Figure 2a) [Schmidt et al., 2011] indicates that volcanic impacts were likely reinforced by external forcing [Mann et al., 2009], but that an explanation of the LIA does not require a solar trigger.

 

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18 minutes ago, bluewave said:

Volcanism may have been the trigger leading to more extensive Arctic sea ice coverage. This would make sense since the cooling began several centuries before the solar minimum.

Abrupt onset of the Little Ice Age triggered by volcanism and sustained by sea‐ice/ocean feedbacks

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2011GL050168

16] Our precisely dated records demonstrate that the expansion of ice caps after Medieval times was initiated by an abrupt and persistent snowline depression late in the 13th Century, and amplified in the mid 15th Century, coincident with episodes of repeated explosive volcanism centuries before the widely cited Maunder sunspot minimum (1645–1715 AD [Eddy, 1976]). Together with climate modeling and supported by other proxy climate reconstructions, our results suggest that repeated explosive volcanism at a time when Earth's orbital configuration resulted in low summer insolation across the NH acted as a climate trigger, allowing Arctic Ocean sea ice to expand. Increased sea ice export may have engaged a self‐sustaining sea‐ice/ocean feedback unique to the northern North Atlantic region that maintained suppressed summer air temperatures for centuries after volcanic aerosols were removed from the atmosphere. The coincidence of repeated explosive volcanism with centuries of lower‐than‐modern solar irradiance (Figure 2a) [Schmidt et al., 2011] indicates that volcanic impacts were likely reinforced by external forcing [Mann et al., 2009], but that an explanation of the LIA does not require a solar trigger.

 

Very interesting insight, will need to get better informed about major volcanic activity pre 1600. 

I'm somewhat puzzled by the claim that the Earth orbital configuration at the time resulted in low summer insolation across the NH. Afaik, the earth's orbital configuration has not changed much in the past 500 years, as the precession cycle is about 26,000 years.

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3 hours ago, etudiant said:

The key article, by Wu et al, is paywalled, but the abstract indicates TSI based on the satellite record since 1978 and before then on a consensus series of  sunspot numbers. 

The modeling may be valid, but as there is no actual data for what happens during a prolonged sunspot minimum, I'm not comfortable using extrapolations from the normal cycle lows.

Clearly something changed during the grand minima and it seems optimistic to assert that TSI was largely unaffected.

 

Separately, the volcanic impact on the LIA remains uncertain. My impression is there were no huge eruptions in the 1600s or the early 1700s, so the LIA cold is hard to blame on volcanoes.

There were multiple VEI 6 (Pinatubo-scale) eruptions during the 17th century. Increasing albedo due to Arctic sea ice growth probably amplified and sustained the cooling trend kicked off by the volcanic eruptions. Feedbacks can amplify trends e.g., the declining Arctic sea ice extent is likely amplifying the impact of warming driven by the rising atmospheric content of greenhouse gases.

IMO, there really is no strong scientific literature that supports the hypothesis that a new Grand Solar Minimum would have a significant impact on mitigating the ongoing anthropogenic warming. Certainly, I haven't found much in the peer-reviewed literature where such hypotheses have gained much support. 

 

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6 hours ago, etudiant said:

Very interesting insight, will need to get better informed about major volcanic activity pre 1600. 

I'm somewhat puzzled by the claim that the Earth orbital configuration at the time resulted in low summer insolation across the NH. Afaik, the earth's orbital configuration has not changed much in the past 500 years, as the precession cycle is about 26,000 years.

I wonder if they just mean that we are beginning the "cool-phase" of the Milankovitch cycle?

Anyway, I do agree with you regarding the lack of true TSI measurements during prolonged periods of low/no sunspots. It would be nice to know with high confidence just how low TSI goes on a GSM.

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This chart provides a good estimate of the impact of natural variation in sun and volcanoes vs man-made CO2. Note the difference in amplitude and time-scale, greenhouse gas  forcing is increasing much faster than the sun changed in the Maunder minimum.

Pages_CO2.jpg

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The reliability of both these charts is iffy imho.

The CO2 data is presumably from the ice cores, which have limited time resolution, as they rely on trapped gases in snow that consolidates only gradually. That smoothes the data a lot.

The temperature data is much more questionable. 

We have more or less global records for a bit over a century and we know that translating these into a single global temperature is a already a difficult exercise,  given the individual records range from -50*C to +50*C at various points. For the prior centuries, we only have proxies, which rarely are purely temperature dependent. That makes anecdotal evidence valuable, so Norsemen raising livestock in Greenland or Roman growing wine in Britain suggest a rather warmer climate than this chart shows

 

 

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The North Atlantic was warm. We already know that. It is my understanding that during the period in which it was warm there it was cool in other places and that the warming described by the anecdotal evidence was not globally simultaneous. The chart above is consistent with both anecdotal evidence and proxy evidence. 

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13 hours ago, etudiant said:

The reliability of both these charts is iffy imho.

The CO2 data is presumably from the ice cores, which have limited time resolution, as they rely on trapped gases in snow that consolidates only gradually. That smoothes the data a lot.

The temperature data is much more questionable. 

We have more or less global records for a bit over a century and we know that translating these into a single global temperature is a already a difficult exercise,  given the individual records range from -50*C to +50*C at various points. For the prior centuries, we only have proxies, which rarely are purely temperature dependent. That makes anecdotal evidence valuable, so Norsemen raising livestock in Greenland or Roman growing wine in Britain suggest a rather warmer climate than this chart shows

 

 

MedievalWarm.thumb.jpg.5c54509673620490bec451e726f8a740.jpg

 

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Exactly. There are multiple lines of evidence that corroborate the global temperature reconstruction graph above. 

One thing that has not yet been mentioned in this thread is the potential role humans had on the LIA. CO2 levels dropped by about 5 ppm possibly at least partly as a result of human activity. This would have put a -0.1 W/m^2 force on the planet. That is a significant portion of the Maunder Minimum forcing.

 

 

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1 hour ago, bdgwx said:

Exactly. There are multiple lines of evidence that corroborate the global temperature reconstruction graph above. 

One thing that has not yet been mentioned in this thread is the potential role humans had on the LIA. CO2 levels dropped by about 5 ppm possibly at least partly as a result of human activity. This would have put a -0.1 W/m^2 force on the planet. That is a significant portion of the Maunder Minimum forcing.

Warming and Cooling: The Medieval Climate Anomaly in Africa and Arabia

Sebastian Lüning, Mariusz Gałka, Fritz Vahrenholt

Abstract

The Medieval Climate Anomaly (MCA) is a well-recognized climate perturbation in many parts of the world, with a core period of 1000–1200 Common Era. Here we present a palaeotemperature synthesis for the MCA in Africa and Arabia, based on 44 published localities. The data sets have been thoroughly correlated and the MCA trends palaeoclimatologically mapped. The vast majority of available Afro-Arabian onshore sites suggest a warm MCA, with the exception of the southern Levant where the MCA appears to have been cold. MCA cooling has also been documented in many segments of the circum-Africa-Arabian upwelling systems, as a result of changes in the wind systems which were leading to an intensification of cold water upwelling. Offshore cores from outside upwelling systems mostly show warm MCA conditions. The most likely key drivers of the observed medieval climate change are solar forcing and ocean cycles. Conspicuous cold spikes during the earliest and latest MCA may help to discriminate between solar (Oort Minimum) and ocean cycle (Atlantic Multidecadal Oscillation, AMO) influence. Compared to its large share of nearly one quarter of the world’s landmass, data from Africa and Arabia are significantly underrepresented in global temperature reconstructions of the past 2,000 years. Onshore data are still absent for most regions in Africa and Arabia, except for regional data clusters in Morocco, South Africa, the East African Rift, and the Levant coast. In order to reconstruct land palaeotemperatures more robustly over Africa and Arabia, a systematic research program is needed.

There are also reasons to believe that the MWP was, in fact, global.

 

 

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6 hours ago, chubbs said:

MedievalWarm.thumb.jpg.5c54509673620490bec451e726f8a740.jpg

 

Thanks for the response, but unfortunately the links in the message are not accessible.

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3 hours ago, chubbs said:

Thank you for these. 

Sadly while the psu paper is fully available and suggests a wide set of proxies were used to derive temperatures to drive the models, it then references Materials and Methods, for this aspect. That part however is not linked.

The Nature paper is only an abstract, the actual paper is paywalled.

Do you have any more useful references, please.

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41 minutes ago, etudiant said:

Thank you for these. 

Sadly while the psu paper is fully available and suggests a wide set of proxies were used to derive temperatures to drive the models, it then references Materials and Methods, for this aspect. That part however is not linked.

The Nature paper is only an abstract, the actual paper is paywalled.

Do you have any more useful references, please.

The PSU link for supporting materials and data is listed at the end of paper:

https://science.sciencemag.org/content/suppl/2009/11/25/326.5957.1256.DC1

The nature paper is here (unpaywall ap):

https://boris.unibe.ch/132301/7/333323_4_merged_1557735881.pdf

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On 2/20/2020 at 10:25 AM, WestBabylonWeather said:

I am not really worried or care about another "mini ice age"

more concerned on how a grand solar minimum would affect things if it were to occur

My understanding is that the GSM will create more earthquakes and volcanic eruptions. If we have enough volcanic eruptions, that may temporarily effect temperatures

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7 hours ago, Fantom X said:

My understanding is that the GSM will create more earthquakes and volcanic eruptions. If we have enough volcanic eruptions, that may temporarily effect temperatures

If a solar minimum can impact the earth enough to boost the earthquake and volcanic activity, we have a lot to learn.

Put me down as deeply skeptical of any such connection.

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18 hours ago, etudiant said:

If a solar minimum can impact the earth enough to boost the earthquake and volcanic activity, we have a lot to learn.

Put me down as deeply skeptical of any such connection.

There is some research.  Check out this book. Whether or not it's true.  That's another story

https://g.co/kgs/vMie7n

 

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1 hour ago, Fantom X said:

There is some research.  Check out this book. Whether or not it's true.  That's another story

https://g.co/kgs/vMie7n

 

That is a too steep paywall for me, to buy the book.

However, if the solar minimum has the effects he claims, there should have been massive quakes in the US during the 1600s. Yet afaik, the biggest earthquake in at least the eastern US was the New Madrid quake in 1811. The big Alaska quakes did not pay much attention to his chronology either.  

There is a slightly more plausible theory involving the barycenter of mass of the solar system, which shifts around the body of the sun with the orbits of the planets. For earthquakes, I'd trust gravity more than temperature, but both still seem deeply implausible to me.

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Also an article from January:

ecmwf-ens_z500_mslp_nhem_9-1

<snip>

Combined with the unusually high pressure in the Pacific, this is a perfect recipe for cold air outbreaks into Canada and western/northern United States. The core polar vortex circulation over the Greenland area promotes cold north flow down into the United States, as seen on the temperature anomaly forecast below. Sadly that means W/SW flow for the SE United States and less chance of a colder winter episode. On the other side, that same polar vortex core over Greenland lowers the pressure in the North Atlantic, and creates a mild zonal flow towards Europe, and promotes pressure building, keeping winter mainly away from the continent. This is a very fine example of a "coupling" between the stronger stratospheric polar vortex and the troposphere.

Source

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On 2/23/2020 at 10:01 AM, Fantom X said:

There is some research.  Check out this book. Whether or not it's true.  That's another story

https://g.co/kgs/vMie7n

 

I looked up John Casey. He claims to be a leading climate expert even though he has no formal academic experience or published any materials in the field. 

In 2008 he predicted that the Earth would cool by at least 1C by 2031. In his book Dark Winter he predicted that by 2020 we would be firmly in the "cold era" that would last through 2045.

According to Berkeley Earth the 5yr centered mean for year end 2008 was 0.57C and 2019 was 0.85C. That means we are now 1.25C away from his prediction. And considering that the temperature has increased since 2008 and with at least a +0.6 W/m^2 energy imbalance on the planet I'm fairly confident that no one on this forum, including even the most ardent of contrarians, would challenge me when I say we aren't even remotely close to a "cold era" and that a 1.25C decline in global temperature in a mere 11 years is essentially impossible.

Note that Mr. Casey claims this epic cooling would be the result of a grand solar minimum so a volcanic eruption or cataclysmic event would not count as verification.

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On 2/16/2020 at 3:06 PM, donsutherland1 said:

There were multiple VEI 6 (Pinatubo-scale) eruptions during the 17th century. Increasing albedo due to Arctic sea ice growth probably amplified and sustained the cooling trend kicked off by the volcanic eruptions. Feedbacks can amplify trends e.g., the declining Arctic sea ice extent is likely amplifying the impact of warming driven by the rising atmospheric content of greenhouse gases.

IMO, there really is no strong scientific literature that supports the hypothesis that a new Grand Solar Minimum would have a significant impact on mitigating the ongoing anthropogenic warming. Certainly, I haven't found much in the peer-reviewed literature where such hypotheses have gained much support. 

 

I'd be more worried about Antarctic ice melt causing a sudden sea level rise in the space of 10-20 years.  That's far more likely to occur than this Grand Solar Minimum thing.

 

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On 2/12/2020 at 6:05 PM, bluewave said:

Some version of this story has been circulating for over 10 years now. Somebody posted it here a while back.. Here is a study explaining how tiny an influence an actual solar minimum would have on global temperatures. This study came out 10 years ago shortly after the deep solar minimum in 2009.


Current temperature data also confirm that the effect of low solar activity on the climate is very small”, notes Rahmstorf. The current has not noticeably slowed down global warming. Over the past 30 years temperatures have increased at a steady rate of 0.16 degrees Celsius per decade.

https://www.pik-potsdam.de/news/press-releases/archive/2010/weakening-sun-would-hardly-slow-global-warming

Weakening Sun would hardly slow global warming

 
03/10/2010 - A new Grand Minimum of solar activity would decrease the rise of global mean temperature caused by human greenhouse gas emissions only marginally. A new modelling study by researchers of the Potsdam Institute for Climate Impact Research, published online today in the journal Geophysical Research Letters, finds a temperature offset of at most 0.3 degrees Celsius until the end of the century. This is less than ten percent of the temperature rise projected under “business as usual” scenarios of the Intergovernmental Panel on Climate Change (IPCC).
Weakening Sun would hardly slow global warming

There are no sunspots visible today. The picture was taken using the Michelson Doppler Imager of the Solar & Heliospheric Observatory Soho. Credit: SOHO (ESA & NASA)

“The notion that we are heading for a new Little Ice Age if the Sun actually entered a Grand Minimum is wrong,” says Georg Feulner, lead author of the study. “In fact,” he adds, “a minimum of solar activity would not prevent strong future warming if emissions of greenhouse gases continued at current levels.”

The observations of sunspots, visible signs of increased solar activity and irradiance, show that the Sun has been in the deepest and longest activity minimum for almost a century. Satellite measurements confirm that solar radiation has never been weaker since records started in the 1970s. Some solar physicists have suggested this could indicate the beginning of a new Grand Minimum comparable to the Maunder Minimum in the late 17th century. The Maunder Minimum is connected to the Little Ice Age with markedly lower temperatures.

To explore the effect of a 21st-century Grand Minimum Feulner and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research used a coupled climate model that consists of models for the oceans, the atmosphere and the land surface. The researchers studied greenhouse gas emission paths corresponding to the A1B and A2 scenarios of the IPCC with intermediate and strong growth of emissions during the 21st century. The authors also accounted for volcanic eruptions, which are unpredictable, by randomly spreading the same eruptions as in the 20th century over the 21st century.

They performed three simulation experiments with different solar forcing: one without a Grand Minimum, repeating the last 11-year solar activity cycle until 2100, and two with the Sun entering a new Grand Minimum lasting till the end of the century. In these minima, solar irradiance is reduced by 0.08 and 0.25 percent of its value in 1950, the former value corresponding to the reconstructed reduction of solar irradiance during the Maunder Minimum.

grand minimum en
Projected changes to the global mean temperature depend more strongly on emissions than solar activity. Credit: PIK

With an 11-year solar activity cycle continued until 2100, global temperatures are modelled to rise 3.7 or 4.5 degrees Celsius above the 1961 to 1990 average level, depending on the emission scenario. These results agree well with recent projections, the authors report. For the reconstruction of the Maunder Minimum under the two IPCC emission scenarios, the temperatures in 2100 lie about 0.1 degrees Celsius lower. For the experiment with a stronger reduction of solar irradiance of 0.25 percent of the 1950 value, the difference is 0.26 degrees Celsius under both emission scenarios.

“Most likely, a new Grand Minimum of solar activity would diminish global mean temperatures in the year 2100 by about 0.1 or 0.2 degrees Celsius,” says Stefan Rahmstorf, head of Earth System Analysis at PIK. 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 three, so the solar cooling effect would very likely not exceed 0.3 degrees.

“A new Maunder-type solar activity minimum cannot offset the global warming caused by human greenhouse gas emissions,” the authors conclude. Moreover, any offset of global warming due to a Grand Minimum of solar activity would merely be a temporary effect, since solar minima typically last for several decades to a century at most.

“Current temperature data also confirm that the effect of low solar activity on the climate is very small”, notes Rahmstorf. The current minimum has not noticeably slowed down global warming. Over the past 30 years temperatures have increased at a steady rate of 0.16 degrees Celsius per decade. According to the surface temperature analysis by NASA’s Goddard Institute for Space Studies, the year 2009, despite the solar minimum, was the second-warmest year on record globally, beaten only by 2005, and by far the warmest in the southern hemisphere. The month of January 2010 was the second warmest January on record globally, beaten only by January 2007.

Article: Feulner, G., and S. Rahmstorf (2010), On the effect of a new grand minimum of solar activity on the future climate on Earth, Geophys. Res. Lett., 37, L05707, doi:10.1029/2010GL042710

 

With an 11-year solar activity cycle continued until 2100

 

Is this the reason we have a bakeoff summer every 11 years since 1922?

 

Also, I wonder if we'll be able to tell any differences with the sun spot cycle during our next total solar eclipse in April 2024, which I will be chasing upstate.

In the eclipse we had a few years ago, multicolored solar protuberances could be viewed on the edge of the sun's limb during totality.

 

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On 5/22/2020 at 4:27 AM, The_Global_Warmer said:

The Earth is still boiling. 

 

The la Nina taking shape will cool temps but they will continue to rise regardless.

Don't you ever get tired of responding to garbage science? I feel you brother.

With the oceans filling with heat worldwide the end is not far away. We have been living in  an illusion and caught up in self-promotion.

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