Search Results for: Maunder

Scientists at JPL now predict a major long term uptick in sunspot activity

9:59 am

The solar science community's failed predictions
The many failed recent predictions of the
solar science community

The uncertainty of science: According to a NASA press release today, scientists at JPL now predict that the Sun will see a major increase in sunspot activity in the coming decades, ending the relatively quiet period seen in the two past solar maximums.

In their paper, the scientists say they come to this conclusion due to changes seen in solar wind activity since 2008. From their abstract:

Over the course of two decades until 2008, the solar wind became significantly weaker with a constant declining trend in many important solar wind parameters, and solar cycle 24 being the weakest on record since the start of the space age. Here we show that since 2008, the Sun has reversed this long-term weakening trend with a steady increase in various solar wind proton parameters observed at 1 au. Furthermore, comparison of values from a fitted trend to data between 2008 and 2025 show the following increases in solar wind proton parameters: speed (~6%), density (~26%), temperature (~29%), thermal pressure (~45%), mass flux (~27%), momentum flux or dynamic pressure (~34%), energy flux (~40%), interplanetary magnetic field magnitude (~31%), and the radial component of the magnetic field (~33%).

This has important implications on long-term solar trends, implying that the exceptional weakness of solar cycle 24 was most likely a recent outlier and that the Sun is not entering a modern era Maunder/Dalton-like minimum phase in its solar variation, but is instead recovering from a ~20 yr decline.

This analysis and conclusion is most intriguing, but we must also remember that every prediction by the solar science community in the past two decades has turned out to be wrong, as illustrated by the graph above. This prediction is just like all those others, in that it is based not on any fundamental understanding of why these changes in the solar wind are occurring, but simply extrapolating this past behavior into the future, a very unreliable method of prediction.

These scientists might be correct, but I would not bet any money on it.

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Do Kepler’s sunspot drawings tell us the length of the solar cycle in the 17th century?

9:19 am

Kepler's first sunspot drawing
Click for original image.

The uncertainty of science: Scientists have done a new analysis of Johannes Kepler’s three drawings of sunspots on the Sun in 1607, and have concluded that the solar cycle at that time — just before the start of the Maunder grand minimum of no sunspots for decades — was about the same length, 11 years, that has been measured since the 1700s onward.

You can read the peer-reviewed paper here. The drawing to the right is figure 1 in that paper, and shows Kepler’s first drawing of the Sun’s surface showing sunspots. From the paper’s conclusion:

In combination with sunspot drawings in the 1610s–1620s, it is reasonable to suppose that the duration of the Solar Cycle −13 was between 11 and 14 yr. This does not support Miyahara et al.’s claim of anomalously long/short durations for Solar Cycle −13 (16 yr) and Solar Cycle −14 (5 yr) but supports Usoskin et al.’s reconstruction of regular durations of Solar Cycle −13 (11 yr) and Solar Cycle −14 (14 yr).

In other words, the solar cycle prior to the sixty-plus yearlong Maunder Minimum, when few to none sunpots occurred, was about eleven years long, like now, and not five years or sixteen years long, as some scientists have theorized. Knowing the length and nature of the cycle before the Maunder grand minimum would help scientists predict when the next minimum might occur. It would also help them better document the Sun’s long term behavior.

There is however great uncertainty in this result, since there really is so little data about sunspots prior to the Maunder Minimum. Before Galileo’s first use of the telescope in astronomy in 1609, such observations like Kepler’s were rare and very difficult. The conclusions here are intriguing, but hardly convincing.

In fact, it is really impossible to get a defiinitive answer from this data. We really won’t know how the Sun behaves just prior to a grand minimum until it happens again and scientists can use modern technology to observe it.

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Scientists: The solar cycle was only 8 years long during the Maunder Minimum in the 1600s

9:58 am

Using archival records gathered in Korea during the 1600s when the Sun was undergoing a long period of almost no sunspots — called the Maunder Minimum — scientists have discovered evidence that the solar cycle during that time was only 8 years long.

You can read their paper here. Since almost no sunspots were visible at that time, the scientists used reports of aurora in Korea to determine periods when the Sun was more active. From their abstract:

By analyzing the variations in solar activity-related equatorial auroras recorded in Korean historical books in the vicinity of a low-intensity paleo-West Pacific geomagnetic anomaly, we find clear evidence of an 8-year solar cycle rather than the normal 11-year cycle during the Maunder Minimum.

This 8-year cycle is shorter than the 9-year cycle that other researchers had estimated based on the few sunspots that did appear during this grand minimum. Both conclusions however challenge what is known of the Sun. Since the 11-year cycle resumed in the 1700s, short cycles have generally been associated with very active periods, the opposite of what has been found during Maunder.

In other words, we know better what happened, but have no understanding of why. Since the Maunder Minimum appears associated with the Little Ice Age of the 1600s, and fits other data that says the climate cools when the Sun produces few sunspots, gaining some understanding of this process is important for understanding past and future changes to the global climate.

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Astronomers discover a solar twin whose sunspot cycle changed into a grand minimum

9:19 am

Astronomers studying the sunspot cycle of several dozen stars that are twins of our Sun have identified for the first time a star whose 17-year cycle suddenly ceased, going into an extended grand minimum.

Comparing these stars to the Sun enables astronomers to better determine how typical – or not – the Sun is as a star. The Sun’s magnetic activity is defined by its 11-year sunspot cycle. Of the 59 stars that Baum’s team surveyed, 29 appeared to also have starspot cycles, and the period of those cycles could be measured for 14 of them.

“Of these 14 stars, the average length of their cycle is just under 10 years, which is similar to the Sun’s 11-year cycle,” Baum tells Physics World. However, not all the stars adhered to this time frame. One star that was surveyed has a cycle lasting less than four years, while another star, HD 166620, had a cycle 17 years long.

Note the past tense. Sometime between 1995 and 2004, HD 166620’s starspot cycle simply stopped.

When or if the star’s sunspot activity resume is unknown. The Sun’s last grand minimum, dubbed the Maunder Minimum, lasted 70 years during the 1600s.

No one yet understands why stars do this. This discovery however now shows that the Sun is not unique in this behavior.

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Sunspot update: Activity in May continued to exceed predictions

11:07 am

Time for our monthly sunspot update. On June 1st NOAA updated its monthly graph showing the Sun’s sunspot activity through the end of May 2021. Below is that updated graph, annotated as always to show the previous solar cycle predictions.

As has happened now for almost every month since the Sun’s sunspot cycle began to increase following the long and deep minimum in 2019, the activity in June exceeded the numbers predicted by the computer models of NOAA’s panel of solar scientists. While the activity dipped slightly from April, it still was more active than predicted.

» Read more

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Sunspot update Nov 2019: The longest flatline in centuries

5:53 pm

The Sun is now in what appears to be the longest stretch ever recorded, since the 11-year solar sunspot cycle reactivated in the 1700s after the last grand minimum, of sunspot inactivity. This record-setting dearth of practically no sunspots has now stretched to six months in a row.

On December 8 NOAA released its November update of its graph showing the long term sunspot activity of the Sun. As I have done now every month since this webpage began in 2011, I have posted it below, with annotations:

November 2019 sunspot activity
The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

In November the Sun saw two official sunspots (here and here) and one active area that never received an official sunspot number, with two of these three weak events having a polarity linking them to the next solar maximum.
» Read more

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Scientists look at and compare two past grand minimums

11:55 am

In a new paper just published by the American Geophysical Union (AGU), scientists have used tree ring data to analyze and compare the last two past grand minimums, dubbed the Spörer Minimum (1432–1578) and the more well known Maunder Minimum (1640–1720).

The link takes you to the full paper. It is very technical but what it essentially finds is that there appear to be some differences between the two, but more important, during the deepest part of both grand minimums all evidence of the 11 year sunspot cycle (dubbed the Scwabe cycle) vanishes.

A detailed comparison between the Spörer and Maunder (CE 1640–1720) minima shows that the Spörer Minimum is associated with enhanced Δ14C variability in a band centered around the 11‐year Schwabe cycle from CE 1450 to 1479 and between CE 1545 and 1578, whereas little 11‐year variability is observed from CE 1479 to 1539. In contrast, we only observe enhanced 11‐year variability after the end of the Maunder Minimum at CE 1722–1744, which could indicate that the nature and origin of the two minima were different.

In other words, from 1479 to 1539 (Spörer) and 1545 to 1722 (Maunder) the data suggests that we would not have seen sunspots, even with today’s superior observational capabilities.

They base this conclusion by looking at carbon-14 data, which reflects the arrival of cosmic rays on the Earth. When the sun is active cosmic rays decrease. When it is inactive, with no sunspots, cosmic rays increase. This data can be compared with known and more recent sunspot cycles, and can thus provide a robust baseline for determining what the Sun’s behavior was like before the era of the telescope.

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Sunspot update March 2019: An upcoming Grand Minimum?

10:04 am

Even though we are now deep into the beginning of what might become the first grand minimum in sunspot activity since the invention of the telescope, that does not mean the Sun has as yet stopped producing sunspots. Yesterday NOAA released its the monthly update of its tracking of the solar cycle, adding sunspot activity for March 2019 to its graph. Below is that graph, annotated by me to give it some context.

It shows the Sun with a slight burst in activity in March, suggesting that though we are now in the solar minimum that minimum still has the ability to produce sunspots.

At the same time, for me to say that we might be heading to a grand minimum, a time period lasting many decades where no sunspots are visible and the sunspot cycle essentially ceases, is not click bait or hyperbole. It is instead based on what I now think the solar science community is thinking, based on this very graph.

March 2019 sunspot activity

The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction, extended in November 2018 four years into the future.

For past half dozen or so cycles the solar science community had issued its prediction for the upcoming solar maximum at about this stage in the overall cycle, during the final ramp down to minimum when it was clear that the Sun had entered that minimum.

This cycle’s prediction however has not yet happened, and in fact appears to be late. In fact, the extension of the May 2009 red curve that was made in November 2018 might very well be the only prediction we see. That extension is shown by the differences between the green 2007 prediction and the red 2009 prediction in the graph. Before November 2018 both curves ended at the same place, the end of 2018.

The extension of that red curve is important. As I noted in my December 2018 sunspot update,
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Weird erosion in large Martian craters

1:25 pm

Central pit in Asimov Crater

Cool image time! In reviewing the images in the December image release from the high resolution camera on Mars Reconnaissance Orbiter (MRO, I came across the image to the right, cropped, rotated and reduced to post here, showing the western half of the central pit of Asimov Crater. (Click on the link for the entire photograph.) The eastern half can be seen here.

It is unusual to see central pits in craters. One instead expects to see central peaks. The pit itself is intriguing because of its sinkhole appearance. In both the northwest and southwest corners you can clearly see drainages flowing down into the pit, including recent faint darkened streaks indicative of past seep avalanches. The same can been seen for the pit’s eastern half. Along the pit’s western rim are parallel cracks suggesting that the plateau itself is slowly shifting downward into the pit.

Furthermore, the rim cliff has multiple drainage gullies, all beginning just below the initial top layers. The look of those cliffs is very similar to what sees on the walls of the Grand Canyon, where the top of the cliffs show layers with the bottom of the cliffs buried under a slope of alluvial fill, material that has fallen to slowly form those slopes. The drainage gullies however would have come later, and suggest that some form of seepage is coming out of the contact between the layers at the top of the slope.

A look at the context image below and to the right reveals the greater mystery of this crater, as well as nearby Maunder Crater, the subject of a recent captioned image release from Mars Odyssey.

context map showing Asimov and Maunder Craters

In both cases a circular interior gully separates the crater floor from the crater’s rim. In fact, the crater floor almost appears raised. This is especially striking with Asimov Crater, where the central floor appears like a very flat plateau, except for that central pit and the surrounding gully.

The MRO team has taken a lot of images of the gullies, which you can see if you zoom in to latitude -46.843° longitude 4.831° on the map image at this website. It is clear that they want to know more about the origins of this geology. It suggests water flow, even though these craters are located in the Martian southern highlands, a place that is more reminiscent of the Moon, with many ancient craters and far less evidence of significant change.

What the geology in these two craters suggest is that some erosion process is eating away at the crater floors, beginning at its edges as well where there are voids below that allow the surface to sink. While that erosion is certainly helped by wind, it also implies the presence of underground water, either as ice or liquid, in the past and even possibly today.

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Sunspot update for July 2018: The Sun flatlines!

10:50 am

Yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for July 2018. As I do every month, I am posting it below, annotated to give it some context.

This might be the most significant month of solar activity that has been observed since Galileo. Except for two very short-lived and very weak sunspots that observers hardly noted, the Sun was blank for entire month of July. This has not happened since 2009, during the height of the last solar minimum.

What makes this so significant and unique is that it almost certainly signals the return of the next solar minimum, a return that comes more than a year early. The solar cycle the Sun is now completing has only been ten years long. It is also one of the weakest in more than a hundred years. This combination is unprecedented. In the past such a weak cycle required a long cycle, not a short one.
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The first sunspots of the next solar cycle

9:53 am

In linking to my sunspot update this week, there has been a lot of speculation at the climate website WattsUpWithThat that the next solar cycle has begun.

Our resident solar physicist, Dr. Leif Svalgaard commented and provided a link to something reported by his colleagues, something that likely would not have been possible without the fantastic solar observations of NASA’s Solar Dynamic Observeratory (SDO). He said: “Cycle 25 has already begun. It looks to me that SC25 will be a bit stronger than SC24, so probably no Grand Minimum this time.” It seems a small sunspot has been observed, that has the opposite polarity of cycle 24 sunspots. [emphasis in original]

The speculation at WattsUpWithThat, which suggested that this sunspot was the first such sunspot this cycle, was not quite accurate however. This sunspot with an opposite polarity, which decayed so quickly that it did not rate getting a sunspot number, was not the first. This week the Solar-Terrestrial Centre of Excellence, a Belgian organization focused on space-solar science, published this very good article discussing not only this sunspot but two others, one of which occurred more than a year ago.
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Sunspot update for March 2018: the sun crashes!

11:49 am

It surely looks like the solar minimum has arrived, and it has done so far earlier than expected! On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for March 2018. Below is my annotated version of that graph.

March 2018 was the least active month for sunspots since the middle of 2009, almost nine years ago. In fact, activity in the past few months has been so low it matches the low activity seen in late 2007 and early 2008, ten years ago when the last solar minimum began and indicated by the yellow line that I have added to the graph below. If the solar minimum has actually arrived now, this would make this cycle only ten years long, one of the shortest solar cycles on record. More important, it is a weak cycle. In the past, all short cycles were active cycles. This is the first time we have seen a short and weak cycle since scientists began tracking the solar cycle in the 1700s, following the last grand minimum in the 1600s when there were almost no sunspots.
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The Sun goes quiet! Sunspot update for November 2017

11:51 am

The past month was the most inactive month for sunspots since the middle of 2009, when the last solar minimum was just ending and the Sun was beginning its ramp up to solar maximum.

NOAA on Sunday posted its monthly update of the solar cycle, covering sunspot activity for November. As I have done every month since 2010, I have posted that graph below, with annotations.

November 2017 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

I have also added a straight yellow line near the bottom of the graph, indicating how the lack of activity this past month corresponds with the lack of activity in the summer of 2009, just when that unusually long and deep solar minimum was beginning to end.

November 2017 sunspot record

To get an idea how few sunspots were seen in November, the graph on the right, produced by SILSO (Sunspot Index and Long-term Solar Observations) on December 1, shows only 10 days during the entire month when any sunspots were active on the Sun’s visible hemisphere. And even those sunspot were few and weak, resulting in tiny sunspot numbers total.

Nor is December looking any different, with no sunspots recorded so far, four days into the month.

The plunge to solar minimum continues to appear to be happening faster than normal. At this pace, solar minimum will arrive in early 2018, making this one of the shortest solar cycles on record. That in itself would be unprecedented, as short cycles in the past have always accompanied very active solar maximums, not weak maximums like the maximum we have just seen.

I still expect the ramp down to solar minimum to slow down and stretch out to 2019, as would be more normal, but I also would not bet any money on this expectation, at this point.

The big question remains: Will the solar cycle continue as normal after this upcoming solar minimum, or will we instead see our first grand minimum since the Maunder Minimum in the 1600s, a period lasting for about a century with no obvious sunspots that also corresponded to the Little Ice Age?

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The sunspot crash continues

3:49 pm

On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for December. As I do every month, I am posting it here with annotations to give it context.

December 2016 Solar Cycle graph

January 2017 sunspots as of January 9, 2017

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

Sunspot activity continues to decline, and it appears to be declining at a steadily faster rate as the solar cycle ramps down towards minimum. Not only did sunspot activity drop below the 2007 low prediction in 2016, since 2017 began the sun has been blank almost continuously, as shown by the graph on the right. The signs continue to point to a solar minimum occurring much sooner than predicted, producing an unprecedented short and weak solar cycle.

Despite this, the appearance in December of the first sunspot for the next solar cycle suggests that we will not be entering a Grand Minimum in the coming decades. It does not guarantee it, as there is some evidence that even though no sunspots were visible during the Maunder Minimum in the 1600s the magnetic activity that causes sunspots did continue, and with our better observation equipment today we may see sunspots they would not have seen in the 1600s.

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The sunspot decline continues

2:59 pm

On Monday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in July. As I have done every month since 2010, I am posting it here, below the fold, with annotations to give it context.

Sunspot counts continue to decline at a rate faster than predicted or is usual during ramp down from solar maximum. Normally the ramp down is slow and steady. This time it has so far been more precipitous. While the 2009 prediction of the solar science community (indicated by the red curve) suggests minimum will occur sometime after 2020, the actual counts suggest it will occur much sooner.

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A new double dynamo theory to explain the Sun’s solar cycle

10:45 am

A team of solar scientists have proposed a new theory that they think explains the ebb and flow of the Sun’s eleven year solar cycle, and if right can explain the periodic occurrence of grand minimums where there are essentially no sunspots for decades, such as the Maunder Minimum in the 1600s.

The theory proposes that the Sun has two different dynamos that produce different magnetic waves in its interior. Like waves that can either cancel each other out or combine for more power, these two dynamos do the same over time and thus effect the Sun’s sunspot/solar cycle.

“We found magnetic wave components appearing in pairs, originating in two different layers in the Sun’s interior. They both have a frequency of approximately 11 years, although this frequency is slightly different, and they are offset in time. Over the cycle, the waves fluctuate between the northern and southern hemispheres of the Sun. Combining both waves together and comparing to real data for the current solar cycle, we found that our predictions showed an accuracy of 97%,” said Zharkova.

Zharkova and her colleagues derived their model using a technique called ‘principal component analysis’ of the magnetic field observations from the Wilcox Solar Observatory in California. They examined three solar cycles-worth of magnetic field activity, covering the period from 1976-2008. In addition, they compared their predictions to average sunspot numbers, another strong marker of solar activity. All the predictions and observations were closely matched.

Looking ahead to the next solar cycles, the model predicts that the pair of waves become increasingly offset during Cycle 25, which peaks in 2022. During Cycle 26, which covers the decade from 2030-2040, the two waves will become exactly out of synch and this will cause a significant reduction in solar activity.

“In cycle 26, the two waves exactly mirror each other – peaking at the same time but in opposite hemispheres of the Sun. Their interaction will be disruptive, or they will nearly cancel each other. We predict that this will lead to the properties of a ‘Maunder minimum’,” said Zharkova. “Effectively, when the waves are approximately in phase, they can show strong interaction, or resonance, and we have strong solar activity. When they are out of phase, we have solar minimums. When there is full phase separation, we have the conditions last seen during the Maunder minimum, 370 years ago.”

And on this same subject, last week NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in June. As I have done every month since 2010, I am posting it here, below the fold, with annotations to give it context.
» Read more

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The Sun makes the scientists look good — for now!

1:53 pm

NOAA today released its monthly update of the Sun’s sunspot cycle, covering the period of May 2013. As I have done every month for the past three years, I have posted this latest graph, with annotations to give it context, below the fold.

For the third month in a row, the Sun has shown increased sunspot activity. Though the total activity continues to remain well below all predictions, it appears that the Sun is going to produce a double-peaked maximum, as predicted by some solar scientists back in March. Be aware however that this prediction isn’t based on any real understanding of the physical processes that produce sunspots but is instead based on the fact that the Sun has sometimes done this in the past. If you asked these scientists why the Sun sometimes produces a double-peaked maximum they will wave their arms about but will really not be able to tell you.

» Read more

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The weak solar maximum continues

3:30 pm

On February 4, NOAA released its monthly update of the Sun’s sunspot cycle, covering the period of January 2013. As I do every month, I have posted the latest graph, with annotation, below the fold.

Not surprisingly, the sunspot numbers in January showed a recovery and rise from the steep plunge in December. What is surprising, however, is that the rise is not very much, barely bringing the sunspot number for the month back to the weak numbers we’ve seen for most of 2012.
» Read more

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The link between sunspots and climate

10:30 am

In a preprint paper published today on the Los Alamos astro-ph website and accepted for publication in the Journal of Atmospheric and Solar-Terrestrial Physics, Norwegian scientists have found a strong correlation between the length of the solar sunspot cycle and the Earth’s temperature during the following cycle. From the abstract:

Relations between the length of a sunspot cycle and the average temperature in the same and the next cycle are calculated for a number of meteorological stations in Norway and in the North Atlantic region. No significant trend is found between the length of a cycle and the average temperature in the same cycle, but a significant negative trend is found between the length of a cycle and the temperature in the next cycle. This provides a tool to predict an average temperature decrease of at least 1.0 ◦ C from solar cycle 23 to 24 for the stations and areas analyzed. We find for the Norwegian local stations investigated that 25–56% of the temperature increase the last 150 years may be attributed to the Sun. For 3 North Atlantic stations we get 63–72% solar contribution. [emphasis mine]

You can download a copy of the paper here [pdf].

Their paper finds that if a particular sunspot cycle is longer with less activity, the climate will show significant cooling during the next cycle.

The paper makes several important points:
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Two climate papers of interest

12:18 pm

When I appear on radio and am talking about climate change, I often get the same questions over and over.

  • Is the climate warming?
  • If so, is human behavior an important factor for causing that warming?
  • How much does the sun influence climate change?
  • Is the ozone hole linked to climate change?

The truth is that, right now, no one can really answer any of these questions with any certainty. While a large majority of climate scientists might be convinced the Earth is warming and that human activity is causing this warming, the public has great doubts about these claims, partly because of the untrustworthy behavior of many of these climate scientists and partly because the science itself is often confusing.

We simply don’t yet have enough data. Worse, much of the data we do have is tainted, unreliable because of the misconduct and political activism of the very climate scientists who are trying to prove the case for man-made global warming.

Two new papers, published today in Geophysical Research Letters, add some interesting but small data points to this whole subject.
» Read more

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The sun’s weak maximum continues

12:27 pm

The monthly graph from NOAA’s Space Weather Prediction Center of the Sun’s solar cycle sunspot activity is out and I have posted it below. Though activity increased for the second month in a row, the totals are still below the activity levels of March and April 2011.

I am beginning to think that I sound like a broken record. This monthly graph once again suggests that the next solar maximum will be weak, possibly weaker than the most up-to-date predictions for the next solar maximum. And even if that prediction is correct, the data continues to point towards a quieter Sun, with the likelihood of a long period of no sunspots beginning in the next decade.

Based on past history, the consequences of a long Maunder-type minimum, where there are no sunspots for decades, should be very profound. Every time the Sun has gone this quiet in the past, the Earth’s climate has cooled. Furthermore, new results just released add weight to this conclusion. A less active Sun allows more intergalactic cosmic rays to hit the atmosphere, and the CLOUD experiment at CERN strongly suggests that the higher rate of cosmic rays could in turn increase the atmosphere’s cloudiness, thereby reflecting more light and energy and making the Earth colder.

The sunspot graph for August 2011

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The battle between global warming and the sun

3:59 pm

The revelation last week that the sun is very likely about to go into a period of little or no sunspot activity has made a lot of global warming advocates, both scientists and journalists, very nervous. For years these climate activists have declared that the Earth’s climate is getting warmer, and that this warming trend was going to do us great harm. Putting aside whether these claims are based on fact (they are not), the possibility that the Earth might instead become cooler because of a dimming of the sun puts this political agenda under threat, and requires some form of immediate action to defuse that threat. See for example this short podcast (with full transcript) from Scientific American. The key quote:

A cooler sun might mean a drop in global average temperatures of at most 0.3 degree Celsius. But the carbon dioxide already in the atmosphere today will add 0.6 degree Celsius to global average temperatures by the end of the century. And more, since greenhouse gas emissions show no signs of diminishing. So the slightly cooler sun won’t counteract a much hotter Earth.

In order to discredit the threat that solar variation poses to global warming, the journalist here acts to minimize any danger from a dimming sun. Unfortunately, he does so by extrapolating a result (warmer climates) based on a very weak foundation: an unproven theory and our very limited knowledge of the climate.
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Solar scientists predict a major decline in sunspot activity

1:37 pm

At a press conference today at the 2011 meeting of the Solar Physics Division (SPD) of the American Astronomical Society (AAS) in Las Cruces, New Mexico, solar scientists predicted that not only will the next solar maximum in 2013 be the weakest in centuries, it is very likely that it will be followed by another long Maunder Minimum, a period of decades without sunspots. “The sun may be going into hiatus,” says Dr. Frank Hill, associate director of the NSO’s Solar Synoptic Network. You can read the press releases for this announcement here and here.

decline in magnetic field over the last few cycles

These conclusions are based on three lines of evidence:

  • There has been a long term weakening in the magnetic strength that produces sunspots themselves. The declining trend suggests that by 2022 it will no longer be strong enough to produce sunspots. The graph above shows this decline.
    » Read more
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After a burst the Sun quiets down again

3:57 pm

Time again for the monthly updated graph of the Sun’s solar cycle sunspot activity. Posted today by NOAA’s Space Weather Prediction Center, you can see the May results in the graph below.

After a three month steady rise in sunspot activity in January, February, and March, the numbers plummeted during April and May. Though the Sun remains active, with only one blank day since January 16, the pattern of activity as it ramps up to solar maximum continues to suggest that we are looking for the weakest solar maximum in two hundred years, as now predicted by solar scientists at the Marshall Space Flight Center.

Whether this weak maximum foreshadows another Maunder-like minimum, with no sunspots occurring for decades, remains unknown. Only time will tell. However, if such a thing should happen, it will be a marvelous opportunity for scientists to finally pin down precisely the actual influence of the Sun on the Earth’s climate. Up until now they can only guess at how much the Sun varies in brightness. Another Maunder Minimum will tell them.

May Sunspot activity

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The solar maximum keep shrinking

2:53 am

Solar scientists at the Marshall Space Flight Center have once again revised downward their prediction for the intensity of the next solar maximum. Key quote:

Current prediction for the next sunspot cycle maximum gives a smoothed sunspot number maximum of about 59 in June/July of 2013. We are currently two years into Cycle 24 and the predicted size continues to fall.

If this prediction holds, the upcoming solar maximum could be the lowest since the cycle came back to life in around 1715 following the Maunder Minimum.

the solar cycle

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Heading towards a Maunder Minimum

10:27 pm

Though I have been saying that the Sun’s lack of sunspots the last two years suggests the possibility of that we might be facing an extended period without solar activity, I am not a solar scientist. Today, in a paper published today on the Los Alamos astro-ph website, a solar scientist says just that. Key quote:

One method that has yielded predictions consistently in the right range during the past few solar cycles is that of K. Schatten et al., whose approach is mainly based on the polar field precursor. The incipient cycle 24 [on-going right now] will probably mark the end of the Modern Maximum, with the Sun switching to a state of less strong activity.

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Climate and Sun science bibliography

Below is a bibliography of all the research I have done on the subject of climate change, with a secondary focus on the question of the Sun’s influence on that climate. This bibliography covers a period from around 2002 until 2010, when I stopped adding to the list. The research continues, but I simply no longer amend this bibliography. I

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