|
Post by lsvalgaard on Jan 2, 2011 15:03:05 GMT
Thanks Leif Seems like things are speeding up. with ever smaller spots [specks]
|
|
|
Post by twawki on Jan 14, 2011 4:30:48 GMT
Is 2015 still the expected spotless period? If this continues then we may not even make a peak of 35 in Solar Cycle 24 depending on which specks get counted.
|
|
|
Post by jimcripwell on Jan 15, 2011 16:54:40 GMT
We have old sunspot 1138(?) just appearing again. I have read that during the Maunder Minimum the same sunspot went round and round the sun many times; I believe as many as 7. Is there a record I can consult somewhere that keeps track of how many revolutions some sunspots are making? I think sunspots get renumbered each time they reappear.
|
|
dh7fb
New Member
Posts: 25
|
Post by dh7fb on Jan 17, 2011 9:34:08 GMT
|
|
|
Post by af4ex on Jan 17, 2011 12:54:46 GMT
dh7fb> It's interesting that the average size of a sunspot in cycle 23 is > out of phase to the ssn, about 3...4 years. Yes, very interesting. If this is a trend for SC24, then that might explain why most of the sunspots we've seen so far seem to be very small (except for 1133/1140 and 1138/1147). I don't think the L&P theory addresses the size specifically, just the contrast vs magnetic field. So, if true we can expect to see the bigger spots at the end of this cycle. Fine business, Frank! John/af4ex
|
|
bradk
Level 3 Rank
Posts: 199
|
Post by bradk on Jan 17, 2011 14:59:16 GMT
Very interesting find! Dr. Svalgaard, was this previously known?
I wonder if this was also true in the Dalton cycles of 4-5?
|
|
dh7fb
New Member
Posts: 25
|
Post by dh7fb on Jan 17, 2011 15:23:03 GMT
Yes, indeed it would be very interesting to know the A/R ratio b4 1875... also for the SC4 as the last "big" b4 the Dalton... anyway: I didn't find some data, not at all for the sunspotarea and those for the SSN have likely a great deviation in relation to the newer data. Sorry 4 that...
|
|
|
Post by lsvalgaard on Jan 19, 2011 2:52:32 GMT
Dr. Svalgaard: Today most sunspots have an average magnetic field strength of 2000 Gauss. In the early 80's most sunspots had a strength of 3000 Gauss (The Secret Sun). Do you know if there are even older measurements? Do L&P have any idea when this effect started? L&P updated. See plot in previous comment. The plot updates.
|
|
|
Post by af4ex on Jan 30, 2011 11:59:20 GMT
I think this pair of images illustrates the crux of the L&P effect. On the left we see a magnetogram showing a two regions of comparable activity. Of course, AR1150, on the right, is somewhat larger than the anonymous region to the left. Comparable in the sense that we have no problem distinguishing two regions of bipolar magnetic activity. Now switch to the SDO continuum image on the right, which renders the scene in the "visible" spectrum. Now we see why 1150 has a number and its anonymous cousin to the left doesn't. All we can see clearly are the 'sunspots', magnetic regions whose field values exceed 1500 Gauss. Furthermore, AR1150 is only partially exposed in this light, as you can see from the exent of the plage (whitish texture), which more faithfully renders the true extent of each region. It seems that our definition of "solar activity" is based too much on what we can see with our rather narrow-band eyeballs. I understand that these definitions have evolved from centuries of solar observation and that the ability to see this activity in its full spectrum is a relatively recent development. But it underscores why the L&P effect is poorly understood by the general public, who seem to over-react to the thought of the 'sunspots' fading away. Attachments:
|
|
bradk
Level 3 Rank
Posts: 199
|
Post by bradk on Jan 30, 2011 13:20:57 GMT
John-
Nice post and very true, the problem with the comment on the public though is not sunspots themselves but what the textbooks used to tell the general public about what a lack of sunspots meant - and that correlation may be the only real training about sunspots the general public recieved in school - that was certainly true of myself in the United States. Now we think we are entering, possibly, another grand minimum it is likely many will make the assumption that what they learned was correct.
|
|
|
Post by af4ex on Jan 31, 2011 12:15:06 GMT
John- Nice post and very true, the problem with the comment on the public though is not sunspots themselves but what the textbooks used to tell the general public about what a lack of sunspots meant - and that correlation may be the only real training about sunspots the general public recieved in school - that was certainly true of myself in the United States. Now we think we are entering, possibly, another grand minimum it is likely many will make the assumption that what they learned was correct. In the next few years I expect we'll learn a lot about the relationship of sunspots to what's really going on with these so-called grand minima. I didn't mean to imply that sunspots counts are useless or somehow wrong. In fact they're very useful in localizing special kinds of high magnetic activity. In effect, they act as a kind of "high pass" magnetic field filter, showing us only the places where B > 1500. For example, 1150 is currently splitting into two spots. Just like 1147 did when it spawned 1149. This is hard to see in the magnetogram and UV imagery, but is very obvious in visible light. (In UV seems to show up best at 1700A). This seems to be a natural thing for large regions to do. The latitude bands rotate at different speeds, effectively creating a force that stretches the region apart along the axis prescribed by Joy's Law. The long filament cavity that 1150 is sitting next to is an extreme example of this stretching. I've watched it grow since it was a small region between old spots 1121 and 1123. In visible light that action is all that is visible, so I look at it as the result of this "high-pass" magnetic intensity filtering. Attachments:
|
|
|
Post by jcarels on Feb 13, 2011 19:56:17 GMT
Leif,
The L&P effect now makes sunspots weaker, but could the L&p effect be some part of a cycle? And that in time it makes sunspots stronger? If possible could there then be more sunspots than the 10.7 predicts?
|
|
|
Post by lsvalgaard on Feb 13, 2011 21:53:39 GMT
Leif, The L&P effect now makes sunspots weaker, but could the L&p effect be some part of a cycle? And that in time it makes sunspots stronger? If possible could there then be more sunspots than the 10.7 predicts? We don't know that, of course, but we do 'know' that since the 1720s the L&P has only occurred once and that to weaken. We 'know' this with some certainty back to the 1830s and with less certainty the century before that. The ingredients in 'knowing' are the relationships between sunspot numbers, cosmic ray modulation, and daily variation of the geomagnetic field. On theoretical grounds I think there is an upper limit to an active region as it is prone to fall apart.
|
|
N9AAT
Level 3 Rank
DON'T PANIC
Posts: 153
|
Post by N9AAT on Feb 15, 2011 23:11:59 GMT
It seems to me that a lot depends on who the media uses for "re-processing" of the data. Most of the public would be bored to tears with raw data, so an editor or re-writer has to edit it for public digestion ... and somehow make it relevant. Networks have to pay the bills, yes, we all know that. This is where things can go in several directions at once if the re-writer isn't careful. Of course most empiracle (sp?) researchers are no good at writing articles for CNN. Someone has to be out there to help the public make sense of things AND understand why research must never end. Or does anyone want to just stop right here and say we now know all that we will ever know?
|
|
AD6AA
Level 2 Rank
Posts: 82
|
Post by AD6AA on Feb 16, 2011 13:54:58 GMT
Leif, With the continuing on of the L&P Minimum, How likely is it we may see a day or two of a SFI of 200 or more this solar cycle? I'm thinking about the ability of the L&P spots to produce massive flares. Inquiring Hams would like to know. Mike AD6AA
|
|