Solar Science

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.

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.

Much excitement from NASA, as the long delayed arrival of Solar Cycle 24 was announced:

Dec. 14, 2007: The solar physics community is abuzz this week. No, there haven’t been any great eruptions or solar storms. The source of the excitement is a modest knot of magnetism that popped over the sun’s eastern limb on Dec. 11th, pictured below in a pair of images from the orbiting Solar and Heliospheric Observatory (SOHO).

It may not look like much, but “this patch of magnetism could be a sign of the next solar cycle,” says solar physicist David Hathaway of the Marshall Space Flight Center.

Yeees, go on…

“New solar cycles always begin with a high-latitude, reversed polarity sunspot,” explains Hathaway. “Reversed polarity ” means a sunspot with opposite magnetic polarity compared to sunspots from the previous solar cycle. “High-latitude” refers to the sun’s grid of latitude and longitude. Old cycle spots congregate near the sun’s equator. New cycle spots appear higher, around 25 or 30 degrees latitude.

OK, got that. Now we have a sunspot with reversed polarity compared to solar cycle 23?

The region that appeared on Dec. 11th fits both these criteria. It is high latitude (24 degrees N) and magnetically reversed. Just one problem: There is no sunspot. So far the region is just a bright knot of magnetic fields. If, however, these fields coalesce into a dark sunspot, scientists are ready to announce that Solar Cycle 24 has officially begun.

And did this coalesce into a sunspot? No. The Sun remains stubbornly blank although there was a fair sized SC23 spot for several days that followed.There appears to be indications of a large sunspot on the far side of the Sun but that too is right on the equator and probably isn’t polarity reversed from SC23.

This isn’t the first time that a sunspot appeared to herald the next solar cycle that failed to materialize. There was another which appeared in late 2006 that got people excited for literally hours when it appeared and disappeared.

Hathaway, it must be remembered, was one of a team who predicted a very strong SC24, at least as strong as the previous one. I think the tension may be getting to him.

I think its OK to actually wait for at least a couple of magnetically reversed sunspots to appear at high latitudes before announcing the Coming of the next Solar Cycle. Whatever happens, SC24 will be late.