Yesterday I lamented that the sun was blank, not only on the SOHO MDI, but also the magnetogram. Within a couple of hours, one sunspeck appeared. I cited Murphy’s Law. As one commenter put it: ” I think if you check back for the last six months or so whenever you mention the lack of sunspots on here, one shows up.”.
Perhaps if I stop writing about the lack of sunspots, a grand minimum will appear. Such power I wield. 😉
The plage area now has no characteristics of a classic spot as you can see on the MDI, but it did yesterday ever so faintly as you can see in a previous MDI image here.
It is rather faint. It is doubtful that pre 20th century astronomers would see it.
NASA’s Dr. Tony Philips, who runs Spaceweather.com also got sucked in by the spotlessness yesterday and wrote this today:
Where have all the sunspots gone? As of yesterday, March 21st, the sun has been blank on 85% of the days of 2009. If this rate of spotlessness continues, 2009 will match 1913 as the blankest year of the past century. A flurry of new-cycle sunspots in Oct. 2008 prompted some observers to declare that solar minimum was ending, but since then the calm has returned. We are still in the pits of a deep solar minimum.
Coincidences and commentary aside, the plage group that appeared shortly after these two posts yesterday is an oddball to be sure. Have a look at the magentogram:
It has the classic high latitude of an SC24 spot, but reversed polarity.
Jan Janssens writes:
” 22 March 09 – New SC24-group has reversed polarity… – The new sunspotgroup that is visible in today’s SOHO-images, has -according to the corresponding magnetogram- a reversed polarity (SC23/25). Though on itself this is not so peculiar (every solar cycle has about hundred such groups, or about 3% of the total), it is already the second SC24-group showing this “aberration”: NOAA 1003, visible for just one day (04 October 2008) on the southern hemisphere (-23°), had a polarity equal to that of a unpair solar cycle too (see slide 4 of my presentation). That makes 2 out of 13 (15%), if this group gets a NOAA-number. ”
Compare the current magnetogram to one where a true SC24 spot did form on Feb 24th, 2009:
The real question is: how long will it last? Most of the cycle 24 spots (and disturbances that don’t rise to spots) have very short lifetimes. Will this new one grow and be assigned a number? Or will it wink out?
We live in interesting times.
Leif Svalgaard (20:38:31) :
Glenn (20:15:40) :
Are you saying that this is a *correlation* of observations of multiple events that describes the process that “grows” sunspots?
“I have no idea what you are talking about. Perhaps you could explain where you want to go with this question or what information you are seeking.”
Well, I’ll rephrase the question.
Are your predictions of solar cycle sunspots “rooted in solid physics” or based on a correlation of observations?
From your example of a correlation I will assume you understand what I mean by correlation in context. Remember you have said that you don’t know what sunspots are or how they are formed. Reply to the above question.
http://en.wikipedia.org/wiki/Correlation_causation
http://en.wikipedia.org/wiki/Correlation
http://en.wikipedia.org/wiki/Causality
Glenn (21:42:22) :
Are your predictions of solar cycle sunspots “rooted in solid physics” or based on a correlation of observations?
Why didn’t you say that in the beginning. Rooted in solid physics, of course, as you well know as I have explained to you in the past. What we predict is the amount of magnetic flux to expect. The process by which such flux concentrates into visible sunspots is not understood [although some people have ideas, e.g. Ken Schatten that I referred you to] and how the spots connect to flux in the interior is also not known, neither is the process the holds the spot together, is a spot one big flux tube or perhaps hundreds of thins ‘strands’ instead, etc, lots of unknowns. To go from magnetic flux to the [arbitrary] sunspot number a calibration point is needed. In our paper we use two such calibration points: cycle 22 and cycle 23.
I hope this helps you in your quest for knowledge, but please do not hesitate to ask further specific questions. I’ll [as is my wont] will do my best to answer them.
Leif,
Thanks, interesting.
“a rotation profile with much of the radiative interior rotating at or below the surface rate, but with a modest increase in the interior.”
Just what I wanted to see. To get a dynamo you need something moving relative to something else, and this opens up for the outer parts moving in one direction and later move in the other direction (relative to the inner parts of course)
and it’s logical to assume that when changing direction the polar field will also reverse. Am I close?
For the “(1) what would make the core do that?” I see all the fun is taking place in that other solar thread so I’ll continue there, but it’s the same old story you will still call nonsense.
lgl (09:24:49) :
“a rotation profile with much of the radiative interior rotating at or below the surface rate, but with a modest increase in the interior.”
Just what I wanted to see.
but you may be cherry picking, the radiative interior rotates markedly slower than the surface rate. Read it carefully. The [synodic] rotation period at low latitudes is about 27 days, in the interior about 28.5 days.
As far as we know the interior rate does not vary [nothing to make it do so on a timescale of solar cycles or even centuries]. The surface does because the magnetic field of solar activity interferes with the rotation [not the other way around]. It is believed that the differential rotation in the convective zone or near the surface [there is no differential rotation in the interior] is important for the dynamo.
Leif,
The [synodic] rotation period at low latitudes is about 27 days, in the interior about 28.5 days.
which means at some latitude the interior and convective zone have the same rotation. Is that where the sunspots are found?
lgl (12:52:51) :
which means at some latitude the interior and convective zone have the same rotation. Is that where the sunspots are found?
That is where many of the spots [but not all] of a new cycle start to form, later on in the cycle the spots move almost to the equator, so at some point early in the cycle the two latitudes are the same.
Hale’s Law. I’m reading along and immediately came across the MMF’s. So perhaps the bright areas I saw today in shreds are MMF’s tearing up the magnetic flux. Still more to read, but I’ll keep an eye on these bright shreds to see where they are going.
Leif: I take it from reading that paper that the bright areas I saw today on the Limb are a bad sign for growing activity in this spot. It’s decaying.
The good news is that the detail I observed is much superior to the MDI image. I don’t know why that would be, but there it was. Jagged bright shreds parallel with the limb. You wouldn’t know it from looking at the MDI Magnetogram or Continuum.
You’ve got to see one of these for yourself.
Robert Bateman (19:35:07) :
You’ve got to see one of these for yourself.
I’ll come one day and visit you. I have seen such things on the projected 4 foot wide image at Kitt Peak. Impressive.
The Polar strength graph at WSO has been updated, showing a possible change in direction?
http://wso.stanford.edu/gifs/Polar.gif
I saved a graph from late last year, is it my imagination or have they revised the Dec 2008 figures?
http://users.beagle.com.au/geoffsharp/polar.jpg
I printed both out and they overlay as being exactly the same.
Thoughts?
the plague area is back at the same place as when this blog started, but the polarity has reversed.
any thoughts?