Solar Science ||

h/t SolarCycle24.com

Another weak SC24 sunspot appears in the southern hemisphere

Would spots this weak have been seen by 19th Century observers?

Hot off the press.

NASA announces yet another explanation for the late arrival of Solar Cycle 24 (nearly two years after it was supposed to have started).

June 17, 2009: The sun is in the pits of a century-class solar minimum, and sunspots have been puzzlingly scarce for more than two years. Now, for the first time, solar physicists might understand why.

At an American Astronomical Society press conference today in Boulder, Colorado, researchers announced that a jet stream deep inside the sun is migrating slower than usual through the star’s interior, giving rise to the current lack of sunspots.

Rachel Howe and Frank Hill of the National Solar Observatory (NSO) in Tucson, Arizona, used a technique called helioseismology to detect and track the jet stream down to depths of 7,000 km below the surface of the sun. The sun generates new jet streams near its poles every 11 years, they explained to a room full of reporters and fellow scientists. The streams migrate slowly from the poles to the equator and when a jet stream reaches the critical latitude of 22 degrees, new-cycle sunspots begin to appear.

Original Caption:
Above: A helioseismic map of the solar interior. Tilted red-yellow bands trace solar jet streams. Black contours denote sunspot activity. When the jet streams reach a critical latitude around 22 degrees, sunspot activity intensifies.

Howe and Hill found that the stream associated with the next solar cycle has moved sluggishly, taking three years to cover a 10 degree range in latitude compared to only two years for the previous solar cycle.

The jet stream is now, finally, reaching the critical latitude, heralding a return of solar activity in the months and years ahead.

“It is exciting to see”, says Hill, “that just as this sluggish stream reaches the usual active latitude of 22 degrees, a year late, we finally begin to see new groups of sunspots emerging.”

The current solar minimum has been so long and deep, it prompted some scientists to speculate that the sun might enter a long period with no sunspot activity at all, akin to the Maunder Minimum of the 17th century. This new result dispells those concerns. The sun’s internal magnetic dynamo is still operating, and the sunspot cycle is not “broken.”

So we should be seeing SC24 sunspots appearing now that the jet stream has reached the critical latitude of 22° ?

Let’s check out of the window:

The spotless disk of the Sun

Magnetogram shows little magnetic behaviour

OK, maybe it was just an off day on the Sun. What about the trend?

So far, indistinguishable from zero.

Here’s the 3D view of what the solar scientists are tracking/modelling (click to see the movie):

This movie reveals motions of the Sun’s interior as measured with helioseismology on data from GONG and SOHO/MDI. East to west motion is color coded: blue is slow, red is fast. A red band in the outer third of the Sun moves slowly down from near each pole toward the equator; that band is the jet stream that is associated with sunpot emergence and the solar cycle. As of early 2009 the Cycle 24 jet streams have just reached N/S 22 degrees latitude, and new sunspots are beginning to emerge.

Now I hate to be a killjoy, but all of this effort has failed to convince me that a deep down “jetstream” of charged plasma reaching a “critical” latitude can explain why the Sun remains so very quiet.

On SolarCycle24.com, they’ve got yet another sun speck recorded yesterday, that by today had disappeared. Exactly the same behaviour we’ve been having for 12 months with no end in sight.

Solar Cycle 24 spot - the start of something?

At least, it could be SC24 but the last magnetogram is from nearly 3 days ago.

I think the true test is if this spot lasts more than 48 hours. The others haven’t lasted that long.

This blog has quiet periods just like the Sun

I’ve just been in e-mail correspondance with Dr Kenneth Tapping, asking him to comment on the progress of the solar minimum and his opinion on the likely size of SC24 when it does deign to appear.

Dear Dr Tapping

After you published your rebuke to Investor’s Business Daily, I put your entire reply onto my blog (see http://solarscience.auditblogs.com/2008/04/22/ken-tapping-the-current-solar-minimum/ ) which I notice is the second listing when anyone googles your name. I hope you didn’t mind.

Since that reply the Sun has appeared to have gone into an even deeper slumber than it was when you wrote your article, more than a year ago. You ended that article with a statement

AT THE MOMENT IT IS UNJUSTIFIED TO ASSUME THE SUN IS UNDERGOING A SIGNIFICANT CHANGE IN BEHAVIOUR. ON THE BASIS OF SUNSPOT NUMBER DATA, WE CANNOT ASSUME ANYTHING ODD IS HAPPENING UNLESS THE NEXT CYCLE DELAYS ITS START INTO 2009 OR 2010

Well it’s now nearly mid-2009 and the only spots to be seen very very occasionally are SC23 polarity.

Do you have any further comment on the Sun’s (lack of) activity? Are we close to unusual times in solar activity? Is the sun undergoing a significant change in behaviour?

Best regards

John

He replied [with my emphasis]

Hi John,

I’ve just got back here from the Space Weather Workshop, which was held in Boulder, Colorado. The opinion there is that the next cycle is coming, although forecasts are for a low cycle with a late start.

Our radio telescopes have detected no sign of the new cycle yet. However a statistical study of indices that I have been doing suggests the Sun did show a significant change in behaviour over the last few years, but that things are starting to slip back towards the normal situation, which could suggest the Sun is at least showing signs of waking up again. It’s deciding to take an additional lie-in cannot be ruled out.

Activity is certainly very low.

Regards,

Ken

When I asked for that “statistical study of indices”, Dr Tapping replied that it was being submitted to a journal and he’d let me know when its in pre-print - which is fine by me.

I think it’s fair to say that all solar scientists have been caught out by the length of the solar minimum and the delay to SC24. In subsequent posts I’ll be reviewing the prognostications of solar models, in an effort to understand what exactly goes into predictions of solar cycles.

In other news, as reported on Watts Up With That:

NOAA/SWPC will be releasing an update to the Solar Cycle 24 Prediction on Friday, May 8, 2009 at noon Eastern Daylight Time (1600 UT) at a joint ESA/NASA/NOAA press conference

I can hardly wait.

NASA’s David Hathaway has announced, again, that Solar Cycle 24 may have begun:

After more than two years of very low sunspot activity and hardly any flares, the sun is ramping up activity now.

The sun’s activity ebbs and flows on a roughly 11-year cycle. It can range from very quiet to violent space storms that knock out power grids on Earth and disrupt radio and satellite communications. The last peak was in 2000, and scientists have in recent months figured the low point was occurring. Fresh sunspots during October suggest the corner has been turned.

“I think solar minimum is behind us,” said David Hathaway of NASA’s Marshall Space Flight Center in Huntsville, Ala. “Last month we counted five sunspot groups.” he says.

Sunspots are cool areas on the solar surface where magnetic energy is bottled up. While five groups is not extraordinary, it is significant in comparison to the months of virtually no spots.

“This represents a real increase in solar activity,” Hathaway said in a statement today.

Your tax money at work. At least he won’t have to keep stretching out the start of SC24 every few months.

Tags: Hathaway, NASA, solar cycle 24

Not a speck. Not a low latitude could-be-a-SC23 spot.

The real deal.

Sun on 13-10-2008 showing SC24 spot

The polarity is definitely reversed from the previous cycle. Its a high latitude spot. The companion spot is reverse polarity to the main spot.

Looks good to me.

The STEREO image (allows us to look around the limb of the Sun and see what’s coming) suggest an even larger area of activity at about the same latitude.

Stereo Image 12-10-2008

Now we wait to see if the SC24 persists.

The magnetogram shows the SC24 polarity:

Magnetogram from 13-10-2008 showing SC24 polarity

The solar magnetic field for September has just been published (as graphed by Anthony Watts) and shows the magnetic field to be at a historically low level, as NASA had already noted.

This may just prove to be the bottom of the Solar Cycle (yes, I’m sticking my neck out). Now we wait to see what happens next, because I’m not convinced that anyone really has a clue.

Yesterday I pulled this magnetogram picture from the SOHO website

Ignoring the phage in the Southern Hemisphere (which is SC23 polarized, natch) there is no magnetic activity at all to speak of.

Throw in the result announced by NASA in the last few days:

“The sun’s million mile-per-hour solar wind inflates a protective bubble, or heliosphere, around the solar system. It influences how things work here on Earth and even out at the boundary of our solar system where it meets the galaxy,” said Dave McComas, Ulysses’ solar wind instrument principal investigator and senior executive director at the Southwest Research Institute in San Antonio, Texas. “Ulysses data indicate the solar wind’s global pressure is the lowest we have seen since the beginning of the space age.”

and

In 2007, Ulysses made its third rapid scan of the solar wind and magnetic field from the sun’s south to north pole. When the results were compared with observations from the previous solar cycle, the strength of the solar wind pressure and the magnetic field embedded in the solar wind were found to have decreased by 20 percent. The field strength near the spacecraft has decreased by 36 percent.

“The sun cycles between periods of great activity and lesser activity,” Smith said. “Right now, we are in a period of minimal activity that has stretched on longer than anyone anticipated.”

Its clear that the Sun has entered a phase that we might never have seen before with anything like modern instrumentation.

The spots on the Sun have become so evanescent and small that we now have the ludicrous arguments over whether a darkened spot that lasts a few hours is counted as a spot or a speck. Anthony Watts refers to this as “Speckwatch” and furthermore even these specks have been SC23 not SC24 polarized.

What is clear is that these spots or specks are way below the range at which our scientific ancestors from the 18th and 19th Centuries could ever have detected.

A quick update on David Hathaway’s predictions for Solar Cycle 24.

Dr Hathaway has changed his prediction once again WITHOUT changing the page that it occurs on (other than the date it was updated), nor with any explanation as to why his previous predictions have been so wrong. It would be nice if he would treat us all to an explanation for modifying his prediction without modifying his methodology.

Here is an animation done by Michael Romayne on how Hathaway’s prediction has changed over time.

Its clear that something so flexible as Hathaway’s predictions cannot have a theory behind them - this is just making ad hoc adjustments. Note also that between March 2007 and March 2008, the expected size of SC24 was reduced - why?

h/t to Anthony Watts 

I’ve not updated the blog for a few months, but its doesn’t mean that nothing has happened in solar science. I’ve just been doing other things, OK?

I’m going to be sending through a large number of posts in the next few days and weeks, as there have been a lot of conflicting signals about whether Solar Cycle 24 has really turned up or not, about whether the Sun has gone into hibernation or not, about the effects on the Earth’s climate (or not).

Be back shortly.

I copy this here because strange things happen to comments on scienceblogs.com. This is a response to this post

Its fascinating Josh, that its not that Sarah Palin is denying that
the Earth’s climate is changing. Simply Gov Palin is making it clear
she does believe that ascribing all or most of the climate change to
mankind’s activities. And she’s far from being alone even in the
scientific community.

Of course, the term “climate change” has been radically redefined to
imply “man-made climate change through the increase of greenhouse
gases, principally carbon dioxide”, and so “climate change denial” or
its variants is simply skepticism over the extent to which recent
climate changes can be ascribed to man-made causes. And of course to
use the term “denier” implies moral depravity rather than skepticism.

So there’s nothing at all in Gov. Palin’s remarks that she needs to
retract, for she, unlike you Josh, does not believe that the climate
change of the last few years is anything out of the ordinary. In that
respect she is solidly with the scientific mainstream and you are very
definitely on the extreme lunatic fringe.

The only reason why this is even controversial is because of the
Mann Hockey Stick - the totem of climate change alarmism - has been
shown to be a shocking fake. What the Hockey Stick did (and like
lemmings, the IPCC followed) was allege that natural climate change in
the last thousand years or so was tiny and benign. And you believed it
Josh.

What has now been fully shown is that the Hockey Stick is actually
an impression of the growth pattern of a group of bristlecone pines in
Colorado. In trying to justify the extraordinary weight given to these
trees in the reconstruction Michael Mann even claimed that these trees
occupied a “sweet spot” to be able to respond to “the global
temperature field” - a remarkable claim that neither you nor any of
your friends can be bothered to explain how a group of trees on a
mountain side in Colorado can fail to respond to local temperature
change yet can somehow respond to a statistical index called “global
temperature”. There’s probably a group of trees somewhere in the world
which show a growth record similar to the Dow Jones 30 - a spurious
correlation like the Bristlecone Pines of Colorado.

That’s because it is magic. Real voodoo. Not science.

So while you’re trying (and failing) to find a single ice core that
shows carbon dioxide rise PRECEDING temperature rise [they all show the
reverse Josh and by around eight centuries], while you’re finding that
an acknowledged expert on PCA (who incidentally believes in AGW) finds
that the Mann Hockey Stick’s decentered PCA to be simply wrong and the
Stick itself to be the result of “dubious statistics”.

I can criticize Gov Palin on many other issues, for I am no
Republican in the American sense of the word. But on the issue of
climate change she is the one talking sense and not you.

The Mann Hockey Stick and its variants are all instruments of real
climate change denial - the preposterous and false notion that the
large scale climate changes of the past never happened while the
present minor changes in climate are hyped up to ludicrous levels. Just
last week James Hansen testified that the opening of one coal-fired
power station in England would lead to the extinction of 400 species -
an extraordinary claim that you will spend exactly no time on verifying
because hey! Life’s too short.