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Post by jcarels on Feb 13, 2011 13:47:53 GMT
Hello, There have been lots of clouds here lately, so I couldn't observe much the last months. Lot's of people on the internet think that SC24 is a copy of SC14. I wanted to see for myself how close the resemblance is, so I downloaded the SIDC data and compared SC24 against all other cycles. I know that the earlier cycles aren't observed completely but this is just for fun! SC10&12 looked a lot more like SC24 than SC14. Just yesterday I noticed that SC9 is almost a copy of SC23, so I also plotted them together (Also have a look at: users.telenet.be/j.janssens/Engzonnecyclus.html#Overzicht |
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Post by jcarels on Feb 13, 2011 14:02:11 GMT
The only conclusing I'm going to make of this is that we still could have an smooth Rmax of 100, if the L&P effect halts. But I don't think that is going to happen soon.  |
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bradk
Level 3 Rank
Posts: 199
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Post by bradk on Feb 13, 2011 14:10:12 GMT
Great points and thank for posting. It is early in this cycle though, and as you note the L & P effect is new thus these comparisons will only get more interesting over the coming months and years.
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Post by bobby80 on Jul 24, 2011 18:30:54 GMT
I have been studying the sun for the past 18 years and it has always gave me a challange when it comes to its behaviour but I think it is a lot like sc12 and it is on a negitive cycle just like in1880s but sc11 has a lot of similar correlations to 23.
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Post by jcarels on Oct 6, 2011 12:35:04 GMT
Time for an update. I've deleted the old graphs to save some space here. I've used the non-smoothed data like the last time, since it goes 6 months further. Attachments:
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Post by jcarels on Oct 6, 2011 12:35:59 GMT
SC24 vs SC10. Looks very good. Attachments:
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Post by jcarels on Oct 6, 2011 12:37:14 GMT
SC24 vs SC12 Attachments:
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Post by jcarels on Oct 6, 2011 12:38:18 GMT
SC24 vs SC14 Attachments:
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Post by lsvalgaard on Oct 6, 2011 17:15:04 GMT
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Post by jcarels on Oct 13, 2011 13:52:29 GMT
Thanks for your suggestion. What was the reaction of the other people (SIDC) at the Sunspot Number workshop to your suggestion? Was it accepted?
Should I also add an extra 10% since 2000 for the SIDC undercount?
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Post by lsvalgaard on Oct 13, 2011 14:26:19 GMT
Thanks for your suggestion. What was the reaction of the other people (SIDC) at the Sunspot Number workshop to your suggestion? Was it accepted? Should I also add an extra 10% since 2000 for the SIDC undercount? It was well received. Formal acceptance is scheduled for the second workshop in Brussels in May 2012. The SIDC undercount is still under investigation, so hold off on that one for now. |
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Post by janjanssens on Oct 14, 2011 19:06:25 GMT
Leif, I think your workshop-presentation proves the SSN really needs to be modified for values prior to 1945. I was wondering on a few things in your presentation: 1. When calculating R Leif, did you determine the Locarno-sunspot-designation (1 through 5) yourself, or did you have the Locarno designations at your disposal? Especially for the complex groups (slides 15-16) this might introduce some difference when decreasing R Loc by your designation (theirs might be different from yours). It's probably not going to be much of an influence, in view of the excellent results from the double-blind test (great idea!). 2. The r 2 for the average weighting factor 1,13 + 0,00040.R (slide 24), based on the years 2003-2011, is only 0,485. This correlation might improve as more data become available. When recalculating the old SSN, one might prefer to use this R-dependent weighting factor in stead of applying a 20%-factor on all old SSN, because the Locarno-effect is by definition less applicable on small sunspots. E.g. with an A1-spot R Loc=R Leif=11 and not 13,2. Because -according to P. McIntosh- nearly 40% of all sunspotgroups are A or B-type groups, this might play a role in the final SSN (obviously no 40%, because very few spots in these groups, so smaller share in total SSN). 3. Should one really correct for the counting of groups (slides 25-26)? To me, deciding whether or not sunspots belong to one group -without using magnetograms or H-alpha-images- is one of the limitations (challenges) solar observers of all time are faced with. Of course, adding these 3% makes the new SSN even more comparable with the other parameters (slides 27-34), but perhaps a one-on-one correlation is not entirely justified. After all, SSN is in visual, thus a (slight?) difference with activity in Ca K, F10,7, foF2 cannot be excluded. 4. In assessing whether or not there is an undercount in the post-2000 SIDC SSN, it might be prudent to consider that as from the year 2000, the internet might have put its stamp on the amateur solar observers to which the SIDC-data are compared. Indeed, daily images, public outreach websites like e.g. Spaceweather.com, blogs, address-groups, e-mail,... were not widespread before that time. In fact, most of the time, they might not be able to compare their observations until receipt of the monthly report from their respective solar sections (< 2000). In view of the instant updates on solar activity available since then, observers might have gone looking more specifically for sunspots and find spots they would otherwise have overlooked - thus creating an artificial SIDC-undercount. And with those highly detailed SDO-images, it's not getting any better. Perhaps there is more to this story, but I thought it could be useful to bring this issue up. I think this is really great research and am looking forward to the revised sunspotnumbers! |
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Post by lsvalgaard on Oct 15, 2011 11:43:29 GMT
Leif, I think your workshop-presentation proves the SSN really needs to be modified for values prior to 1945. I was wondering on a few things in your presentation: I think this is really great research and am looking forward to the revised sunspotnumbers! 1: On the drawings I have the Locarno designation for each group, but not for every spot. That I determine myself and apparently well enough] from my experience with the data. After all, I've looked at 42,000 spots. 2: We try to keep the adjustments to a minimum, especially since the sunspot number is somewhat subjective anyway. 3: the group issue is still to be investigated more fully. I consider it important because groups have a weight of 10 in the Wolf formula. 4: there is not much one can do about this. One may hope that not all observers do this. |
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Post by Ole Doc Sief on Jun 5, 2013 4:31:57 GMT
Thanks for your suggestion. What was the reaction of the other people (SIDC) at the Sunspot Number workshop to your suggestion? Was it accepted? Should I also add an extra 10% since 2000 for the SIDC undercount? It was well received. Formal acceptance is scheduled for the second workshop in Brussels in May 2012. The SIDC undercount is still under investigation, so hold off on that one for now. So I must have missed your post somewhere Dr Svalgaard as to the May 2012 conference...did they finally agree with your theories as to need to correct past data? |
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