Tag: sun

Pluto’s solar wind interaction more like a planet’s

9:11 am

Data from New Horizons has found that Pluto, in its interaction with the solar wind, behaves more like a planet than a comet.

Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that’s part gas- and part battery-powered, Pluto is a hybrid, the researchers say. “This is an intermediate interaction, a completely new type. It’s not comet-like, and it’s not planet-like. It’s in-between,” McComas said. “We’ve now visited all nine of the classical planets and examined all their solar wind interactions, and we’ve never seen anything like this.”

…Pluto continues to confound. Since it’s so far from the sun – an average of about 5.9 billion kilometers (3.7 billion miles) – and because it’s so small, scientists thought Pluto’s gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, “Pluto’s gravity clearly is enough to keep material sufficiently confined,” McComas said. Further, the scientists found that very little of Pluto’s atmosphere is comprised of neutral particles converted to electrically charged ions and swept out into space.

As I’ve written previously, we simply don’t know enough yet about planets to come up with a reasonable definition. As far as I’m concerned, Pluto will remain a planet until we do.

3 comments

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.

6 comments

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.

Leave a comment

Big solar storm not so big

10:01 am

The uncertainty of science: A new analysis of the the 1859 giant solar storm, the first ever detected and dubbed the Carrington event after the scientist who discovered it, suggests that its strength was not global as previously believed, and that it only effected a few spots on Earth.

Up until now the Carrington event has been considered the strongest solar storm to ever hit the Earth, and has been used by the solar satellite industry as a wedge to demand funding for solar warning satellites, claiming that if a similar storm was to ever hit the Earth again without warning, it would destroy civilization as we know it. This new data suggests that this threat has been over-stated.

Why am I not surprised?

One comment

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.
» Read more

4 comments

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.
» Read more

Leave a comment

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.

» Read more

Leave a comment

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.

» Read more

Leave a comment

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).

» Read more

3 comments

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.

» Read more

7 comments

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

4 comments

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.

One comment

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.

One comment

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.

» Read more

2 comments

Another Falcon 9 launch success

4:14 pm

The competition heats up: A Falcon 9 rocket today successfully put a NASA solar observation satellite into orbit.

They have also said that they have achieved splashdown of the first stage, though no details yet on how soft that splashdown was.

Update: SpaceX reports that “the first stage successfully soft landed in the Atlantic Ocean within 10 meters of its target. The vehicle was nicely vertical and the data captured during this test suggests a high probability of being able to land the stage on the drone ship in better weather.”

Leave a comment

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.
» Read more

Leave a comment

Weather 90% go for Falcon 9 launch today

9:14 am

The weather looks almost perfect for tonight’s Falcon 9 launch.

The Falcon 9 will put a solar observation satellite into orbit. While many left wing media outlets will wax poetic about this is Al Gore’s satellite, it is hardly that. It might have been built initially under his misguided idea of creating a propaganda satellite to take daily images of the Earth (images that are essentially of little use for climate studies), DSCOVR has been very carefully redesigned to give it a real purpose, monitoring the solar activity of the Sun and providing a replacement/back-up for ACE, which is now more than a decade overdue for replacement.

The Falcon 9 launch will also attempt again to land intact its first stage on a floating barge. If this attempt succeeds the entire future of space travel will be reshaped.

Leave a comment

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.
» Read more

Leave a comment

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.

3 comments

Signs of a sunspot ramp down

1:39 pm

The monthly update by NOAA of the solar cycle is out, showing the sunspot activity for the Sun in October, As I do every month, I am posting it here, with annotations to give it context.

Despite the appearance last month of the largest sunspot in almost a quarter century, the number of sunspots in October dropped significantly, bringing overall activity back to levels seen in 2012, prior to the second peak in the solar maximum. If things go as expected (not something I would bet much money on), the overall ramp down of sunspot activity should now continue over the next few years. There will obviously be jumps periodically, but the general output of sunspots should steadily decline.

I also want to reiterate what I noted last month, that the 2009 prediction of the solar scientist community is looking better and better with time. Other than over-estimating the total activity somewhat while missing the dip between the two peaks, their overall curve, indicated by the red line, is reasonably close to what has actually happened.

October 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.

One comment

Largest sunspot in a quarter century spews flares

8:31 pm

The largest sunspot seen in about a quarter century produced another powerful X-class flare today, the sixth in less than a week.

This was the sixth X-class solar flare from NOAA 2192, a record for the number of X-class flares generated by a single group so far this solar cycle. It was also the fourth X-class flare since last Friday, continuing a period of intense flaring activity. This sunspot group has grown again a bit, and maintains its magnetic complexity. A degradation of the HF radio-communication was observed over South-America, the Caribbean, and West-Africa.

The last sentence is referring to some radio communications blackouts that have occurred in these areas because of the flares. For more information about the sunspot itself, go here.

And in case you hadn’t noticed, as predicted by many doomsday fear-mongers in the science community, our technological civilization was destroyed by these flares and we are now all dead.

One comment

Solar minimum to limit interplanetary manned flights?

9:45 am

A new study suggests that the increased cosmic radiation reaching the inner solar system because of the Sun’s weak sunspot activity will increase the exposure to dangerous radiation levels for interplanetary astronauts, thus limiting mission lengths to about one year.

The new research finds that, during periods of low solar activity, a 30-year-old astronaut can spend roughly one year in space—just enough time to get to Mars and back—before the constant bombardment by cosmic rays pushes the risk of radiation-induced cancer above current exposure limits.

If the sun’s activity continues to weaken as many scientists predict, the number of days humans could spend in deep space before reaching their exposure limit could decrease by about 20 percent, making future crewed space flight more dangerous, according to the new study accepted for publication in Space Weather, a journal of the American Geophysical Union.

The numbers were worse for women, whose exposure would become dangerous in only 300 days, according to the study.

2 comments

A reviving solar maximum

12:32 pm

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

As much as I am always willing to point out the errors and foibles of scientists when they get something wrong or overstate their conclusions, I also believe it right to give credit when credit is due. I have been saying for several years now that the prediction of the solar scientist community, indicated by the red curve in the graph below the fold, had seriously overstated the Sun’s sunspot production during this solar maximum.

Well, it now appears that, as the solar cycle continues to run its course, that their May 2009 prediction is becoming increasingly correct.
» Read more

Leave a comment

The first of two coronal mass ejectors from a solar flare has arrived.

11:14 pm

An alert has been issued so that the electrical grids can been properly prepared to avoid damage by the impact of these two coronal mass ejections (CME) against the Earth’s magnetic field.

The first of the two CMEs predicted to arrive today made its appearance right on time. G1 ((Minor) geomagnetic storming is expected to begin within the next few hours with a maximum projected level of G2 (Moderate) storms for September 12th. A G3 (Strong) Geomagnetic Storm Watch is still in effect for September 13th due to the combined influence of this CME and the one projected to arrive late on the 12th. G1 (Minor) storming is likely to continue into September 14th. In addition, the S1 (Minor) solar radiation storm that is in progress as a result of the eruption on September 10th is expected to persist for the next few days with a possible slight increase with the arrival of the CMEs. Keep in mind that the forecast periods listed are in Universal Time so aurora watchers in the northern U.S. should be looking for possible activity tonight through Saturday night.

While there has been a lot of fear-mongering about these two CMEs, I expect that the only consequences we will see from both, the biggest to hit the Earth during this solar maximum, will be the possibility that the northern lights might be visible in places farther south than normal.

Leave a comment

The solar maximum lingers on

1:09 pm

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

The sunspot activity of the Sun in August hovered at the same levels seen in July. Though the month had seen periods of little activity, these were interspersed with many violent flaring sunspots, including one that only yesterday unleashed a powerful X-class flare that is expected to send a coronal mass ejection directly at the Earth and should impact the Earth’s magnetic field on September 12. Expect spectacular auroras!
» Read more

6 comments

The lingering weak solar maximum

4:36 pm

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

For the first time in four months the decline in sunspots ceased, though the sunspot count hardly rose either. Instead the numbers stayed almost the same in July as they were in June. This was during a month that began with lots of sunspots, and yet saw the first blank sun in almost three years. In fact, the Sun’s activity in July was a roller coaster, as noted by the Solar Influences Data Analysis Center (SIDC) of the Royal Observatory of Belgium.
» Read more

One comment

The first blank Sun since 2011

1:03 am

No sunspots on July 17, 2014

For the first time since August 14, 2011, the Sun showed no sunspots on its surface today. It started the day, July 17, 2014, with one small sunspot, but that spot apparently decayed away by the end of the day, as indicated by the fact that the sunspot number for the day was listed as zero, the first time that has happened since the solar maximum ramp up began in 2011.

This is strong evidence that the ramp down to solar minimum is beginning.

3 comments
1 … 5 6 7 8 9 … 13