Tag: sun

Sunspot update for February 2018

12:25 pm

It’s time for my monthly sunspot update. On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for February 2018. Below the fold is my annotated version of that graph.

Sunspot activity in February continued the low activity seen in November, December, and January, with November 2017 still the most inactive month for sunspots since the middle of 2009. In fact, the low activity we are seeing now is somewhat comparable to the low activity seen during the ramp down to solar minimum in the first half of 2008. By the end of that year we had hit solar minimum, the deepest and longest in a hundred years, suggesting that we might even hit solar minimum before the end of this year. That would have this happen at least a year earlier than all predictions.
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Sunspot update for January 2018

11:51 pm

Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for January 2018. Below is my annotated version of that graph.

As you can see, the low sunspot activity of the past two months continued in January. November 2017 remains the most inactive month for sunspots since the middle of 2009. January is now the second most inactive month, with December a very close third.

January 2018 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 activity continues to track close to but considerably below the 2007 weak prediction, the difference appears to be increasing as the ramp down to solar minimum continues. While I have said in past updates that the trend suggests an early arrival of the solar minimum, a close look at the previous ramp down in 2007 and 2008 shows that when activity became this weak, the ramp down slowed considerably. This previous pattern suggests that we could see another year or two of similarly low activity before the minimum arrives.

Regardless, the low activity, this soon, continues to suggest that the next maximum will also be weak, and might even not come at all, as some solar scientists have proposed. Instead, we might be heading toward another Grand Minimum, with no significant sunspots for decades.

Will that Grand Minimum produce cold weather worldwide, as it appears to have done during the last Grand Minimum in the 1600s? There is circumstantial evidence in the past decade that it might. We will not know, however, until it happens, and that possibility remains very uncertain.

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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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Solar storm activates global aurora on Mars

12:00 pm

The strong solar flare that occurred earlier this month was strong enough to activate a global aurora on Mars.

The solar event on Sept. 11, 2017 sparked a global aurora at Mars more than 25 times brighter than any previously seen by the MAVEN orbiter, which has been studying the Martian atmosphere’s interaction with the solar wind since 2014. It produced radiation levels on the surface more than double any previously measured by the Curiosity rover’s Radiation Assessment Detector, or RAD, since that mission’s landing in 2012. The high readings lasted more than two days.

Strangely, it occurred in conjunction with a spate of solar activity during what is usually a quiet period in the Sun’s 11-year sunspot and storm-activity cycle. This event was big enough to be detected at Earth too, even though Earth was on the opposite side of the Sun from Mars.

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Sunspot update for August 2017

10:52 am

Yesterday NOAA posted its monthly update of the solar cycle, covering sunspot activity for August. That graph is posted below, with annotations.

August 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.

The long slow decline to solar minimum has now shown itself. Up until now, the ramp down from solar maximum had been fast and steep, unlike past solar cycles where the ramp down is slow and steady. The last few months the ramp down had practically ceased. In this August graph the ramp down turned into a temporary ramp up. Considering the strong activity going on right now as well as the past week, I expect the September numbers to also show this increase.

None of this means that the ramp down has ended, or that we will not see a solar minimum. All it means is that it takes awhile for the Sun to slowly calm down after each solar maximum. The sunspots we are seeing right now, all near the equator, are from the solar cycle now slowly ending. We will know the minimum is coming as well as the next solar maximum when the first tiny and rare sunspots appear in high latitudes. These high latitude sunspots will belong to the next cycle, and will have reversed polarity.

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Ten planetary probes track a solar eruption through the solar system

9:02 am

The path of an October 2014 solar eruption was tracked by ten different spacecraft, including Curiosity on the surface of Mars, as its blast moved outward through the solar system.

The measurements give an indication of the speed and direction of travel of the CME [Coronal Mass Ejection], which spread out over an angle of at least 116 degrees to reach Venus Express and STEREO-A on the eastern flank, and the spacecraft at Mars and Comet 67P Churyumov–Gerasimenko on the western flank.

From an initial maximum of about 1000 kilometers per second (621 miles per second) estimated at the sun, a strong drop to 647 kilometers per second (402 miles per second) was measured by Mars Express three days later, falling further to 550 kilometers per second (342 miles per second) at Rosetta after five days. This was followed by a more gradual decrease to 450–500 kilometers per second (280-311 miles per second) at the distance of Saturn a month since the event.

The CME was first detected by solar observatories Proba-2, SOHO, Solar Dynamics Observatory, and STEREO-A.It was then tracked as it moved outward by Venus Express, Mars Express, MAVEN, Mars Odyssey, Curiosity, Rosetta, Cassini, and even New Horizons and Voyager 2.

On my last appearance on Coast to Coast, I was specifically asked if the probes to Venus, Mars, and other planets have the capability to track solar events. I knew that the Voyager spacecraft had equipment to do this, but was unsure about other planetary probes. This article answers that question.

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Sun’s core rotates 4X faster than surface

8:24 am

The uncertainties of science: Scientists have discovered that the core of the Sun rotates four times faster than its surface layers.

The rotation of the solar core may give a clue to how the sun formed. After the sun formed, the solar wind likely slowed the rotation of the outer part of the sun, he said. The rotation might also impact sunspots, which also rotate, Ulrich said. Sunspots can be enormous; a single sunspot can even be larger than the Earth.

The researchers studied surface acoustic waves in the sun’s atmosphere, some of which penetrate to the sun’s core, where they interact with gravity waves that have a sloshing motion similar to how water would move in a half-filled tanker truck driving on a curvy mountain road. From those observations, they detected the sloshing motions of the solar core. By carefully measuring the acoustic waves, the researchers precisely determined the time it takes an acoustic wave to travel from the surface to the center of the sun and back again. That travel time turns out to be influenced a slight amount by the sloshing motion of the gravity waves, Ulrich said.

This phenomenon had been predicted more than twenty years ago, but never observed until now.

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New data suggests Sun undergoing fundamental changes

8:40 am

The uncertainty of science: New data, when compared with similar data collected over decades, suggests the Sun’s solar cycle is undergoing some fundamental changes.

In work just published in the Monthly Notices of the Royal Astronomical Society, the team shows that the interior of the Sun has changed in recent years, and that these changes persist in the current cycle. In combination with theoretical models, the observations suggest that the magnetic field distribution in the outer layers may have become a bit thinner. Other seismic data shows that the rotation rate of the Sun has also undergone some changes in the way the Sun rotates at different latitudes.

“Again, this is not how it used to be and the rotation rate has slowed a bit at latitudes around about 60 degrees. We are not quite sure what the consequences of this will be but it’s clear that we are in unusual times. However, we are beginning to detect some features belonging to the next cycle and we can suggest that the next minimum will be in about two years,” says Elsworth.

First, they don’t know what will happen because of these changes. Second, their data confirms that the solar minimum will occur in about two years, which would make this cycle only 9 years long, one of the shortest but also one of the weakest that has been observed, two things that previously had never gone together.

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Sunspot update for June 2017

11:47 am

Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for June. As I have done every month since 2010, the graph is posted below, with annotations.

June 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.

Sunspot activity in June was almost exactly the same as in May, and thus continued the overall downward trend that is below the 2007 low prediction and that suggests that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. The Sun is once again blank today for the first time in about two weeks, repeating the pattern we have seen for several months where, because one hemisphere of the Sun is blank while the other hemisphere has some sunspots, the rise and fall of the sunspot counts tracks the 27-day solar rotation almost precisely.

There continues to be evidence that the Sun is undergoing significant changes this solar cycle, all of which are pointing to the possibility that a grand minimum is coming, with no sunspots for decades. And as I have said now monthly for six years, past grand minimums have consistently occurred at the same time the Earth’s climate has cooled. The scientific link remains unclear, but if we should undergo a grand minimum in the coming decades, we will finally have the opportunity to find out what that link is.

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Sunspot update for May 2017

10:32 am

Last week NOAA posted its monthly update of the solar cycle, covering sunspot activity for May. Unfortunately, there appeared to be a problem with their posting software. Though the date of the image changed, the graph itself was not updated. I contacted NOAA, and Ann Newman, IT Specialist at NOAA’s
Space Weather Prediction Center, took a look and quickly fixed the problem.

The corrected graph is posted below, with annotations, as I have done now every month since 2010.

May 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.

The decline in sunspot activity resumed in May, putting the trend back below the 2007 low prediction. Overall, the trend continues to suggest that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. As the Sun is at this moment blank, and has been for several days, I expect that June will end up with low numbers as well, continuing this trend.

As I have repeatedly said now monthly for six years, if history is any guide, the Sun’s low activity should correspond with cooler temperatures here on Earth. Why this happens is not yet understood, though there are theories.

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NASA names next solar mission after pioneer solar scientist Eugene Parker

10:31 pm

NASA has named its next solar mission, which will fly closer to the Sun than any previous mission, after pioneer solar scientist Eugene Parker, who in the 1950s predicted the existence of the solar wind.

The new moniker honors pioneering University of Chicago astrophysicist Eugene Parker, who predicted the existence of the solar wind — the stream of charged particles flowing constantly from the sun — back in 1958. [Solar Quiz: How Well Do You Know Our Sun?]

NASA has named about 20 space missions after people; the Hubble Space Telescope is perhaps the most famous example. But the 89-year-old Parker is the first researcher to be celebrated in this manner while still alive, agency officials said.

Parker deserves it, for sure, and it is really nice to honor him while he is still alive to appreciate it.

The spacecraft is scheduled to launch at the end of July.

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Sunspot update for April 2017

3:53 pm

Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for April. It is posted below, with annotations, as I have done now every month since 2010.

April 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.

April showed an uptick in sunspot activity, enough to move the numbers back up above the 2007 low prediction. Nonetheless, activity as the cycle has been ramping down has consistently and generally remained below expectation, and does seem heading to an early arrival of solar minimum, sometime in late 2019 or early 2020, about a year early.

I don’t want to sound like a broken record, as I have written this practically every month since I started these updates in 2010, but this short and weak solar maximum suggests the possibility that we might be facing a grand minimum, where there are no significant sunspots for decades. Some solar scientists think this is coming. Others are much more doubtful. Regardless, we can only wait and watch, while also recognizing that weak solar maximums and grand minimums have in the past consistently coincided with global cool weather. The reasons why this has happened are not yet known, but it has happened nonetheless.

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Sunspot update for March 2017

11:32 am

On April 3, while I was in the Grand Canyon, NOAA posted its monthly update of the solar cycle, covering sunspot activity for March. As I have been doing every month since 2010, I am posting it here with annotations to give it context.

March 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.

The decline in sunspots continues to run below predictions, suggesting an end to this solar cycle and a solar minimum as early as sometime in 2018. And as I noted in my February update, sunspot activity continues to track the Sun’s 27 day rotation, alternating every two weeks between blank and active hemispheres. We had the longest stretch, more than two weeks, without sunspots in March. This was followed by about two weeks of activity, followed by several blank days and a relatively inactive Sun at present, beginning a little less than a week ago. I expect this period of inactivity to last another ten days or so, and then things will pick up again.

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The longest stretch of no sunspots since 2009

10:45 am

The Sun just completed its longest stretch, 15 days, without sunspots since 2009, suggesting once again that the solar minimum is coming much sooner than expected.

So far this year the Sun has been blank 34% of the time, a pace that makes this year almost as blank as 2009, the year in which the previous solar minimum ended. This suggests that 2017 might be the year in which the next solar minimum begins, which would be about two years earlier than the earliest predictions.

The more likely scenario is that 2018 will be the year the solar minimum begins, with 2019 when solar activity bottoms out. This will still be much earlier than expected, making this solar cycle only about 9-10 years long. What makes this more significant is that historically short cycles always went with high activity, while long cycles signaled an inactive and weak maximum. This cycle will be the first that is both short and weak.

What happens next remains the big question. Will the Sun enter a grand minimum, with no sunspots for decades? Or will sunspot activity continue? Since solar scientists really do not yet understand the mechanism within the sun’s magnetic field that causes this solar cycle, we really can’t answer these questions, in advance. We must wait, and see.

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Sunspot update for February 2017

10:04 am

On Sunday NOAA posted its monthly update of the solar cycle, covering sunspot activity for February. As I have been doing every month since 2010, I am posting it here with annotations to give it context.

February 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.

The decline in sunspots continues. Though the increase in activity from January held in February, the overall activity remains significantly below the predictions, and continues to point to a much earlier arrival of the solar minimum, sometime in 2019.

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The Sun turns

11:33 am

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

January 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.

Since my last solar cycle update, sunspot activity showed a slight increase in activity when compared to the previous month. Overall, however, the ramp down from solar maximum continues to underperform the predictions, and suggests that this solar maximum will not only be a very weak one, but a short one as well.

January’s activity however illustrated a statistical phenomenon that is typical of the sunspot count. That count is determined not by the numbers of sunspots on the entire surface of the Sun, but on the sunspots visible on the side of the Sun facing the Earth. Since it is not unusual for one face to be more active than the other, as we transition from maximum to minimum the sunspot counts will often show a more pronounced up-and-down curve reflecting this fact. Since the Sun’s day equals about 27 Earth days, this means that about every two weeks the active side will dominate our view until it rotates away and the inactive side reveals itself for two weeks.

Silso daily sunspot graph, January to February 2017

This pattern was very evident in January, as shown by the graph on the right and obtained from here. During the first two weeks of the month the Sun was blank. Then that inactive face rotated out of view. For the next two weeks or so the sunspot count went up, then began to drop as the active face began to rotate out of view to be replaced by the blank face last seen in early January.

This pattern of course is very fluid, as at any time the inactive face can become more active and the active face less so. Nonetheless, for short periods covering one to three months it helps to partly explain the up-and-down pattern of sunspot fluctuations during this time period when large portions of the Sun’s face are blank.

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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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First sunspot for the next solar cycle spotted

11:42 am

Solar scientists have spotted the first sunspot on the Sun with a reversed polarity, meaning that it really belongs to the next sunspot cycle.

This is not unusual. The sunspots from different cycles routinely overlap by several years, with the sunspots from the old cycle moving close to the equator with time and the new cycle sunspots appearing at high latitudes. What this does suggest is that there will be sunspots after the upcoming solar minimum, rather than the beginning of a new Grand Minimum with no sunspots for decades.

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Sunspot activity continues to drop

3:21 pm

NOAA yesterday posted its monthly update of the solar cycle, covering sunspot activity for November. Below is my monthly annotated version of that update.

November 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.

In November sunspot activity dropped again, to the second lowest point seen since 2010. Essentially, activity today is about where it was in 2010 when the solar minimum was finally ending. Now, the solar maximum is ending and we are beginning the next solar minimum.

Throughout the entire just completed solar maximum, the Sun continuously under-performed all predictions. Even now, despite following almost precisely the prediction of the 2007 low prediction during 2014 and 2015, in 2016 the ramp down has begun to slip below that prediction. The trend continues to suggest the arrival of solar minimum will be early, possibly as early as sometime late next year.

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Sunspot ramp down resumes

9:31 am

On Monday NOAA posted its monthly update of the solar cycle. I am posting it here, as I do every month, with annotations to give it context.

September 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 two months of increased sunspot activity, the decline in sunspots resumed in September, though activity did not drop significantly. Overall though, the ramp down towards the next solar minimum continues to track quite closely the ramp down predicted by weak prediction made by half the solar science community back in 2007 (the lower green curve above). These scientists however do not have much to brag about. Their same prediction completely missed the ramp up, which happened a year later than predicted, as well as the activity peak, which was far weaker than predicted.

In fact, the ramp down now continues to point to the possibility that this very weak solar cycle will also be a very short one, something that is quite unprecedented, and suggests that we might be seeing the lead in to another Grand Minimum, where there are no sunspots for decades. Since no one understands yet exactly why such grand minimums happen, however, this remains pure speculation. We will only find out by watching what happens, as it happens.

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Sunspots: A recovery in August

10:32 am

NOAA’s monthly update of the solar cycle was posted today. As I do every month, I am posting it here, with annotations to give it context.

August 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 recovery in sunspot activity that began in July continued in August. The number of sunspots increased enough to once again raise the overall curve up to match the green curve of the 2007 weak prediction. Even so, this solar maximum remains far weaker than the weakest prediction. Also, this solar maximum, which started later than all the predictions, looks like it will be far shorter than all the predictions. As I have noted previously, this is counter to all previous solar cycles, where it is the more active cycles that are shorter and the weaker cycles are longer. Here, we are getting a weak cycle that is also short, which once again suggests that we are seeing solar behavior previously unobserved. The solar cycle is doing things it hasn’t done since scientists began studying it closely after Galileo.

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An update on Stereo-B’s status

12:04 am

The engineers working to recover Stereo-B, the solar observatory that was lost for 22 months, have released an update on the spacecraft’s condition.

In the subsequent days, analysis revealed the spacecraft was in a complex spin, with its fuel tanks frozen and the battery state of charge at 30%. The prime goal is now to fully recover battery power and gradually thaw STEREO-B’s instruments and fuel tanks from its deep freeze. It may be clear that the spacecraft is still in a critical condition and that it will take quite some time before imagery, such as those from its twin STEREO-A, will be available again.

If you are interested in more details, go to the Stereo-B update website, where they are posting almost daily reports.

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Contact re-established with dead solar satellite

5:43 pm

Good news! After almost two years since contact was lost, NASA has re-established communications with Stereo-B, one of two solar research satellites designed to study the hemisphere of the Sun that does not face the Earth.

NASA re-established contact with a wayward sun-watching science satellite Sunday nearly two years after the spacecraft suddenly dropped off line during a test, the agency said in a statement Monday. NASA’s Deep Space Network, or DSN, “established a lock on the STEREO-B (spacecraft’s) downlink carrier at 6:27 p.m. EDT,” NASA said in a statement. “The downlink signal was monitored by the Mission Operations team over several hours to characterize the attitude of the spacecraft and then transmitter high voltage was powered down to save battery power. “The STEREO Missions Operations team plans further recovery processes to assess observatory health, re-establish attitude control and evaluate all subsystems and instruments.”

This is a big deal. Not only is it a testament to the spacecraft’s good design, it demonstrates the skill of the engineers at NASA who have regained contact.

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Sunspot ramp down continues

9:36 am

Below is NOAA’s monthly update of the solar cycle, posted by them on August 7. It shows the Sun’s sunspot activity in July, with annotations.

July 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.

As expected, there was a recovery in sunspot activity in July compared to June. Also as expected, the recovery was not significant, so that it appears, based on the past two months, as if the ramp down to solar minimum is accelerating so that solar minimum will occur sooner than expected, possibly as soon as two years.

I would not put much stock on that prediction, however. When sunspot activity first reached this level during the past solar cycle in late 2005, it still took three more years before solar minimum was reached. If this cycle matches the last, that would mean that this cycle, from minimum to minimum, will have lasted 10 years, making a short solar cycle though not one of the shortest. However, it is more likely that the ramp down will stretch out, as it usually does, gliding downward to solar minimum in a slow gentle curve that makes for a full cycle of about 11 years.

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SDO not returning data

8:55 am

For reasons that remain unexplained, the Solar Dynamics Observatory (SDO) did not return to science mode after it passed through the Moon’s shadow on August 2nd.

The only information about this on the SDO webpage simply states, ” The spacecraft did not go back into Science mode at the end of the transit. SDO FOT members are looking into the issue.” Spaceweather.com notes that “Since the transit no new data have appeared on SDO public websites.”

SDO has only been in orbit for six years. It would be a shame to lose it so quickly.

UPDATE: It appears that engineers are getting SDO back into operation. Hat tip James Fincannon.

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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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