Archive for the ‘News and Views’ Category
The SOHO instruments are offline while new software commands are uploaded. As the main instruments are offline, the other CCD systems are being baked out (heated up to clear dead pixels)
Solar and Heliospheric Observatory (SOHO) is having a minor problem. SOHO’s white light solar telescope is temporarily offline while new commands and data tables are uploaded to the spacecraft. Normal operations are expected to resume in a few days.
Hence no updates on the state of the Sun.
The Sun could have a sudden burst of activity and we’d never know.
The Sun has gone back to blank after having had just one sunspot group that caused otherwise rational people to go off their heads…
Here’s the magnetogram of the Sun showing precisely nothing that presages any sunspot formation:
As a comparison, here is the sun image from the Extreme ultraviolet Imaging Telescope at 304 ångstroms for today and near solar maximum in 2000 by way of comparison
Now its easy to see how quiet the Sun really is at the moment. The prominences are weak, the coronal holes are very small, the corona (the solar atmosphere) shrunken.
All of this can be seen to be normal behaviour for the Sun, except that this hiatus between Solar Cycle 23 finally winding down and the next cycle is unprecedented in nearly a hundred years. (By the way, the overuse of “unprecedented” by climate alarmists has me wincing at using it as a cliché)
Eventually the solar cycle must return. The question is whether solar scientists gain insight into the behaviour of the Sun by understanding why their models failed (see below). The result can only be better science.
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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.
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:
OK, maybe it was just an off day on the Sun. What about the trend?
So far, indistinguishable from zero.
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.
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?
He replied [with my emphasis]
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.
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.
Not a speck. Not a low latitude could-be-a-SC23 spot.
The real deal.
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.
Now we wait to see if the SC24 persists.
The magnetogram shows the 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.”
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.