|
|
Post by Bob k6tr on Feb 25, 2011 19:24:10 GMT
Wonder if that would have made X class if it had been more Earth Facing. In a word the answer is no. Flares are measured as they emerge from the Corona of the Sun. Where they are located on the sun has no bearing on the measurement. |
|
|
|
Post by af4ex on Feb 25, 2011 19:31:42 GMT
arjan> ... it must have slowed down alot, even reversed direction ... Perhaps Dr. S. can shed some light on this question about the comet's momentum. Also have another comment for Dr. S: Thanks for the pointer on SWAN (where SOHO uses backscattered UV to estimate active regions on the far side). I found this paper where some researchers tried to correlate SWAN data using LASCO CME's as ground truth, but had poor results. (Good thing we have STEREO) orion.ph.utexas.edu/~windmi/LASCO_SWAN_SolPhys.pdf
|
|
|
|
Post by chickenlittle on Feb 25, 2011 21:57:26 GMT
Can you do something about the ads on page 18 of this discussion thread?
|
|
|
|
Post by Kevin VE3EN on Feb 25, 2011 22:24:13 GMT
Can you do something about the ads on page 18 of this discussion thread? If you're talking about the Ad beside the YouTube video... the ad is automatically inserted by the message board. I could pay to make this message board Ad Free, however I do not think it is worth it at this point. |
|
|
|
Post by lsvalgaard on Feb 25, 2011 23:06:46 GMT
arjan> ... it must have slowed down alot, even reversed direction ... Perhaps Dr. S. can shed some light on this question about the comet's momentum. Also have another comment for Dr. S: Thanks for the pointer on SWAN (where SOHO uses backscattered UV to estimate active regions on the far side). I found this paper where some researchers tried to correlate SWAN data using LASCO CME's as ground truth, but had poor results. (Good thing we have STEREO) orion.ph.utexas.edu/~windmi/LASCO_SWAN_SolPhys.pdf I don't think it could reverse direction. The CME is really thin. But the CME could have dragged with it some of volatiles that are evaporating off the comet. |
|
|
|
Post by af4ex on Feb 26, 2011 3:45:02 GMT
That little B-class blip at 0120Z (green circle) didn't seem significant in x-rays, but it was surprisingly bright in microwaves (like a C-class flare), and seemingly synchronized with the future AR11165 south of the equator. They both flashed on and off at the same time. I hoping these new regions will help to get activity back up where it was last week. :-| Attachments:
|
|
|
|
Post by THEO BAKALEXIS on Feb 26, 2011 8:41:37 GMT
|
|
|
|
Post by af4ex on Feb 26, 2011 13:47:49 GMT
@theo > www.solar-007.eu/site/ Thanks, Theo, nice summary of the current solar situation. The article about the "Giant Magnetic Holes the Size of the UK" caught my eye. After reading it I had to laugh because it gives several false impressions: 1) that the British Isles are really huge on a solar scale! (Just the opposite is true: they're micro-sized) 2) that these researchers have somehow just discovered sunspots (these "dark magnetic holes") In fact I found another article on the Web which shows the "holes" in question in relation to the "UK" (plus Ireland). Looks to me that sunspot group is at least Earth-sized, probably larger (below right). beforeitsnews.com/story/441/501/A_Hole_Bigger_Than_The_United_Kingdom.htmlActually, I'm not even sure about their claim about being the first to observe these "sausage waves". I found this paper where Japanese researchers claimed first direct observation of sausage waves in 2009, based on 2007 Hinode data: iopscience.iop.org/0004-637X/702/2/1443/apj_702_2_1443.text.htmlPerhaps the Sheffield team were the first to make Earth-based observations of the sausage waves (using the Dunn Solar Telescope in New Mexico). The Japanese observations were based on satellite data. Apparently these "sausage waves" are just one of the MHD oscillation modes inside the sunspot flux tubes. Another mode is "kink wave" (below left, from the Japanese paper). I think these correspond to longitudinal and transverse vibrations, sort of like the P and S waves in terrestrial seismology. Is that roughly correct, Dr. Svalgaard? Attachments:
|
|
|
|
Post by lsvalgaard on Feb 26, 2011 17:04:48 GMT
|
|
|
|
Post by sigurdur on Feb 27, 2011 5:12:49 GMT
|
|
|
|
Post by semimadscientist on Feb 27, 2011 22:34:16 GMT
We have just seen that the very first surge of cycle 24 in the North has already cancelled out the old flux [granted that there wasn't much to begin with Dr. Svalgaard, I wasn’t expecting this very dramatic surge in F10 flux and sunspot number, and your own hunches on this matter interest me a good deal. I’ve got a few questions which I’ve been itching to ask, and would gratefully receive answers thereon: What do you mean exactly by “old flux”? Do we have any more info on the polarity of that coronal hole? If it’s the one I’m thinking of, it may not have lasted long enough to tell. How does this compare to the “surge” in sunspot number of August 1904, and were these regions of similarly low latitude? Thanks, and sorry for the surge in questions! |
|
|
|
Post by lsvalgaard on Feb 28, 2011 3:02:53 GMT
We have just seen that the very first surge of cycle 24 in the North has already cancelled out the old flux [granted that there wasn't much to begin with Dr. Svalgaard, I wasn’t expecting this very dramatic surge in F10 flux and sunspot number, and your own hunches on this matter interest me a good deal. I’ve got a few questions which I’ve been itching to ask, and would gratefully receive answers thereon: What do you mean exactly by “old flux”? Do we have any more info on the polarity of that coronal hole? If it’s the one I’m thinking of, it may not have lasted long enough to tell. How does this compare to the “surge” in sunspot number of August 1904, and were these regions of similarly low latitude? Thanks, and sorry for the surge in questions! 'old' and 'new' are relative, of course. In this context, old would be flux of the same polarity as the polar field has had the past several years, and 'new' would be flux of the opposite polarity. Which coronal hole precisely? We don't have any magnetic measurements from 1904, so hard to tell. |
|
|
|
Post by Bob k6tr on Feb 28, 2011 6:38:38 GMT
The Uncorrected Monthly Mean Sunspot Number for February looks to wind up around 52. The Corrected Number should be in the 29 to 33 range. This is a 60% jump from January and a 25% increase over the previous high Monthly Mean Sunspot Number of 25 set 5 months ago.
|
|
|
|
Post by sunspotboy on Feb 28, 2011 14:41:18 GMT
Dr Svalgaard,
It looks like sunspots 1163 and 1164 have a reversed polarity...
Can you comment on this question?
Thank you!
|
|
|
|
Post by lsvalgaard on Feb 28, 2011 15:01:08 GMT
Dr Svalgaard, It looks like sunspots 1163 and 1164 have a reversed polarity... Can you comment on this question? 3% of all spots are reversed [by chance]. It looks like the spots have rotated from their original orientation. This happens often. It might be interesting to follow the regions to see if they continue to rotate. Here is the evolution of the region:  |
|
