Tag: solar cycle

The Sun is blank again

2:01 pm

More signs that we are easing down to solar minimum: After a period of two weeks of sunspots, the Sun has once again gone blank.

It takes the Sun’s about four weeks to rotate and complete one “day”. What has essentially happened is that right now one face of the Sun is blank while the other face has sunspots. For two weeks, from the last week in June to the first week in July, the blank face was turned towards the Earth. Then the face with sunspots rotated into view for two weeks, and now the blank face has rotated back to face us.

Though new sunspots can always form on either face, I expect this blank stretch to last a few days, at least.

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A short but weak solar maximum?

3:03 pm

On July 4th NOAA released its monthly update of the solar cycle, showing the Sun’s sunspot activity in June. It is annotated and posted below.

June 2016 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.

Not surprisingly, the time periods with no sunspots in June, including a 12 day stretch that just ended today, is reflected by the graph’s precipitous drop in June.

What is significant to me is the speed with which this solar maximum seems to be ending. Normally, weak solar cycles are also long solar cycles. The Sun not only doesn’t get as active, but the ramp up and down is extended, as is the period of the solar minimum. This is what happened during the solar minimum from 2007 to 2010. It was longer than normal, which meant that the solar maximum occurred much later than predicted by the 2007 predictions of the solar science communities (shown in green).

This recent stretch of blank days however is now suggesting that the solar maximum is going to end much sooner than the later 2009 prediction (shown in red). Even more astonishing, the numbers in June aligned with the 2007 high prediction, which would make this one of the shortest solar maximums on record!

I don’t expect these low numbers to continue. I expect sunspot activity to recover and continue, with the minimum likely occurring after 2018. If it does come sooner, however, that will once again be evidence suggesting we are heading for a Grand Minimum, with no sunspots for decades.

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Sunspot cycle update

9:56 am

NOAA today released its monthly update of the solar cycle, showing the Sun’s sunspot activity in May. It is annotated and posted below.

Mayl 2016 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.

Though sunspot activity increased in May, the increase was not significant. The ramp down from solar maximum continues to track the 2007 low prediction for this maximum.

Meanwhile, the Sun continues its first multi-day string of blank days since 2011, now up to 3 days with all indications suggesting it will continue at least one more day. This early blank string, combined with the relatively fast decline in sunspots in the past two years, suggests that the solar maximum is ending sooner than predicted by the 2009 prediction (the red curve above), and that the next minimum will possibly be longer as well.

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No sunspots for the first time in two years

10:13 pm

For the first time since July 17, 2014, and only the second time since 2011 at the beginning of the solar maximum, the Sun was blank today, with no sunspots visible on its surface.

I expect the next monthly update of the solar cycle will arrive early next week, and though I expect it will show a slight increase during the past month, it will also show that the ramp down to solar minimum is continuing unabated.

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Computer simulation models Sun’s magnetic field during grand minimum

9:11 am

The uncertainty of science: A computer simulation, run for six months on a supercomputer, suggests that during grand minimums in the Sun’s solar cycle, when there are no sunspots for decades, its magnetic field remains strong but descends into the star’s interior.

I think this statement by the leader of the science team is most informative:

‘The Sun as such is impossible to replicate on present-day computers – or those of the near future – due to its strong turbulence. And indeed we are not claiming that this modelling would really be the Sun. Instead, it is a 3D construction of various solar phenomena by means of which the star that runs our space climate can be better understood,’ Käpylä explains.

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Sunspot activity crashes

10:19 am

The monthly NOAA update of the solar cycle was released yesterday, showing the Sun’s sunspot activity in April. It is annotated and posted below.

April 2016 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.

After four months of steady decline matched exactly with the low prediction from 2007 (the lower green line curve), in April sunspot activity plummeted to the lowest level seen since January 2011.

This decline shouldn’t surprise anyone. The now ending solar maximum has been the weakest in a century and, as noted here, it is now more than a year since the last X-class solar flare, the most powerful kind, with this solar maximum seeing only 45 X-class events, compared to 126 during the previous solar maximum.

As I have noted repeatedly, the big question now is what will happen during the next solar cycle. Will we get another weak solar cycle or will the sun’s sunspot activity recover? Or will sunspots vanish and will the sun enter a grand minimum, with no sunspots for decades? At the moment no one knows, though some solar scientists favor the latter.

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The sunspot decline continues

11:18 am

NOAA’s monthly update of the solar cycle was released today, showing the Sun’s sunspot activity in March. It is annotated and posted below.

March 2016 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.

For the fourth month in a row the change in the graph is so small you almost need a magnifying glass to see it. Despite this, the decline remains remarkably steady, tracking precisely the decline predicted by the low prediction of the 2007 predictions (indicated by the smaller green line curve).

Recently the number of sunspots has dropped enough that I suspect we are not far the moment when we will once again begin to see days where the Sun is blank of sunspots, a situation last seen in 2010 near the end of the previous solar minimum. When that happens, it will herald the beginning of the next solar minimum.

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Monthly Solar Cycle update

11:07 am

NOAA released on Monday its monthly update of the solar cycle, showing the Sun’s sunspot activity in February. I am once again posting it here on Behind the Black, as I have done monthly since 2010.

February 2016 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.

The change in this month’s graph is so small that you will have to look real close to see it. Essentially, the February sunspot activity dropped only a tiny amount from January’s numbers, though it did drop. As such the decline from solar maximum continues to track perfectly the decline predicted by the low prediction of the 2007 predictions. This prediction success should not be taken very seriously, however, since that same prediction expected the solar maximum to begin two years earlier than it actually did.

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The long decline to solar minimum

4:40 pm

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

What strikes me about this month’s continuing and steady decline in sunspots is how much it illustrates the long and steady nature of the ramp down to solar minimum, even for cycles that are very active. If you look at the ramp down during the previous solar cycle on the graph below the fold, it took four full years to reach solar minimum from a comparable sunspot level to what we have today.
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Sunspot decline continues

12:06 pm

NOAA’s monthly update of the solar cycle, showing the Sun’s sunspot activity in December, was posted earlier this week, and I am posting it here, as I do every month, with annotations to give it context.

The decline in sunspots continues, tracking closely the rate of decline predicted by the 2007 and 2009 predictions (the lower green curve and the red curve) but the overall solar maximum has been far shorter and less powerful than predicted.
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Sunspots continue predicted decline

4:30 pm

On Sunday NOAA posted, as it does each month, its monthly update of the solar cycle, showing the Sun’s sunspot activity in November. And as I have done every month since 2010, I am posting it here, with annotations to give it context.

Though sunspot activity in November was just slightly higher than in October, the increase was so small that it is insignificant. Essentially, the overall decline in sunspot count continues, matching almost perfectly the ramp down predicted by the 2007 low prediction. Solar activity continues to be far weaker then anything seen in a century. Whether this suggests a coming Grand Minimum, however, is not known. Solar activity could continue to decline as we move into the next solar cycle, or it could recover. Our understanding of what causes the sunspot cycle remains somewhat fuzzy, which means our ability to predict what will happen next is as fuzzy..

November 2015 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.

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Decline to solar minimum continues

11:26 am

It’s that time again buckos! On Monday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in October. As I have done every month since 2010, I am posting it here, with annotations to give it context.

The decline in sunspot continue steadily, matching the red prediction curve except that, as it has for this entire solar maximum, the number of sunspots continues to be less than expected. Not only did the ramp up start later and not quite reach the levels predicted, the ramp down started early. Overall, this now ending solar maximum is the weakest in a century. The big question remains: Is the Sun about to head into its first Grand Minimum since the 1600s, or is this weak maximum a one-time event to be followed by stronger activity in later cycles.

No matter what anyone tells you, no one knows.

October 2015 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.

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Solar ramp down jumps slightly

9:56 am

My original post about NOAA’s October update to its monthly tracking of the Sun’s sunspot cycle contained an incorrect graph. For reasons I do not understand, the first graph they posted did not include the data for September, thus creating for me the illusion that little had changed in September. I am now posting the correct graph here, below the fold, with annotations to give it context.

In September numbers showed a slight jump in sunspot activity, though once again nothing so significant as to change the overall trends. Moreover, the correction doesn’t change what I wrote previously in any way: the rate of decline seems to have transitioned down from the 2009 prediction (red curve) to the 2007 weak prediction (lower green curve). This doesn’t real mean much, as the sunspot number can still vary up and down considerable before we reach solar minimum in two or three years.

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Ramp down in sunspots continues

12:59 pm

Correction! For reasons I do not understand, the graph below, originally posted on the NOAA website, was incorrect and was changed several days after I posted my piece below. See this post for the correct graph and analysis.

The uncertainty of science: On Monday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in September. Once again I post it here, below the fold, with annotations to give it context.

For the third month in a row the sunspot count dropped a tiny amount, lingering at about the same number as the previous two months. Moreover, the rate of decline seems to have transitioned down from the 2009 prediction (red curve) to the 2007 weak prediction (lower green curve). This doesn’t real mean much, as the sunspot number can still vary up and down considerable before we reach solar minimum in two or three years.

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Decline to solar minimum

9:17 am

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

The sunspot count continued its decline, though dropping only a small amount. Regardless, the decline continues at a rate far faster than predicted or is usual during the ramp down from solar maximum. If this rate of decline should continue, we will reach solar minimum sometime late in 2017, two years earlier than predicted (as indicated by the red curve).

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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.
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Ramp down to solar minimum continues

12:11 pm

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

May 2015 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.

Sunspot activity once again increased in May, though it continues to remain below the 2009 prediction of activity. Though it is still early in the ramp down, a look at the present pattern suggests that (as I also noted last month) sunspot activity is declining much faster than normal. In the past, the ramp down after solar maximum was long and drawn out, while ramp up was much faster. This ramp down seems much more precipitous than past solar cycles.

I should add that in early April Sunspot Index and Long-term Solar Observations (SILSO) had declared that the peak of the solar maximum had occurred in April 2014, and that they could now sum up the overall weakness of this maximum.

Cycle 24 proves to be 30% weaker than the previous solar cycle, which reached 119.7 in July 2000, and thus belongs to the category of moderate cycles, like cycles 12 to 15, which were the norm in the late 19th and early 20th century. Compared to strong cycles, such cycles typically feature a broader maximum, with a 3-year plateau on top of which two or more surges of activity can produce sharp peaks of similar height.

I had missed this announcement when it was first posted. It is worth noting however, especially since their discussion in April is interesting to read in the context of what has happened since.

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The Sun drifts downward

10:11 am

NOAA today posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in April. As always, I am posting it here, with annotations to give it context, as I have done since 2010.

April 2015 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.

Though sunspot activity increased in April, it remained well below the predicted numbers from the 2009 prediction, as has sunspot activity generally done for this entire solar cycle.

Note that if you extrapolate the red curve of the 2009 prediction down to its end you find that the solar minimum was predicted to occur sometime after 2020. Based on the rate of activity we have seen for the past year, it is very possible that the minimum will occur sooner, and will likely last longer.

But then again, the sun does what the sun wants to do. We don’t exactly understand the root causes of the solar cycle, and can only watch it unfold time after time as we try to peel back its mysteries.

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The sunspot crash continues

11:12 am

On Sunday NOAA posted its monthly update of the solar cycle, showing the Sun’s sunspot activity in March. I am posting it here, with annotations to give it context, as I have done since 2010.

March 2015 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.

In February the Sun’s sunspot activity plunged, dropping way below the prediction of the solar science community. In March that plunge continued. Even though activity had seemed to track that prediction through most of 2014, the overall levels were always less than the prediction. The sunspot numbers for the past two months have simply made this fact obvious once again, dropping to levels almost as low as those last seen in 2011, before the onset of the solar maximum.

That the ramp down at this time is so precipitous is especially intriguing, as historically the ramp down from previous solar maximums has been slow and steady. It is once again evidence that the Sun is doing things that solar scientists have never yet had the opportunity to observe.

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Sunspots crash in February

9:54 am


NOAA today posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in February. As I have done monthly for the past five years, I am posting it here below the fold, with annotations to give it context.

In the past two months I have noted how the ramp down from solar maximum has closely tracked the 2009 prediction of the solar scientist community (indicated by the red curve).

In February, however, that close tracking ended, with sunspots plunging far below the prediction. Note also that sunspot activity in March has also been weak.

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SDO celebrates its fifth year in space with a time-lapse of the Sun

9:40 am

Cool images! In celebration of Solar Dynamics Observatory’s fifth year in space observing the Sun, the scientists at the Goddard Space Flight Center have released a time-lapse movie showing the Sun for the past five years.

Video below the fold. It is astonishing and hypnotic. The movie images were taken one image every 8 hours beginning in 2010. If you compare the Sun at the beginning of the movie with the end, you can see the slow shifting of sunspots/flares from higher to equatorial latitudes, as is normal as the solar cycle ramps up to solar maximum and beyond.
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Sunspot activity tracks prediction

1:43 pm

On Monday NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in January. As I do every month, I am posting it here below the fold, with annotations to give it context.

As I have noted previously, the ramp down from solar maximum continues to track the 2009 prediction of the solar scientist community (indicated by the red curve) quite closely. As NOAA also notes,

While awaiting final confirmation, all evidence points to the most recent solar maximum having peaked at 82 in April, 2014. This was within the expected range for the peak, but occurred significantly later than predicted.

Since their graph doesn’t show the entire curves for their predictions, the above statement seems reasonable. However, looking at the graph with those curves inserted (see my annotated graph below the fold), it becomes clear that not only did the peak occur much later than predicted, the maximum’s overall activity was also generally less than predicted.
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The sunspot cycle update for December

3:49 pm

The monthly update by NOAA of the solar cycle, showing the sunspot activity for the Sun in December, was released this past weekend. As I do every month, I am posting it here, below the fold, with annotations to give it context.

Even though sunspot activity in December increased, the slow ramp down to solar minimum continues to track the 2009 prediction of the solar scientist community. The overall intensity of the solar maximum prior to 2014 was considerable less than this prediction, but the numbers throughout 2014 matched that prediction remarkably well.
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Solar maximum ramp down continues

10:01 am

The monthly update by NOAA of the solar cycle, showing the sunspot activity for the Sun in November, was released on December 8, just before NOAA completely revamped its website. As I have been doing every month for the past four years, I am posting it here, with annotations to give it context.

As noted in previous months, the 2009 prediction of the solar scientist community is looking better and better with time. Though there was an increase in sunspot activity in November, the overall trend continues downward very close to that prediction, though at levels that have generally been less than predicted.

November 2014 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.

Future updates will depend on whether NOAA continues to track sunspots using these same standards. After much searching I was finally able to locate the graph above at this link, suggesting that at least for now, they are holding to these standards. I note however that the links to the 2007 and the 2009 solar cycle predictions have vanished down the memory hole. Fortunately, I still have this data, and can continue to annotate the graphs to compare prediction with actual data.

That they might have removed these predictions from their webpage however is a shame. I have emailed them to ask them about this and will let you know what I learn.

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