Tag: sunspots

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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Recreating the changing giant starspots on a distant star

11:46 pm

Astronomers have recreated what they think is the evolution of the giant sunspots on a distant star, covering the period from 2006 to 2012.

More importantly, Künstler’s team measured the time it takes for starspots to decay and used that information to estimate properties of the star’s magnetic field. For example, the star’s activity cycle appears to last about 26 years, more than double the Sun’s 11-year cycle.

You can see a video of this recreation at the link.

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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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