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Pages: 1 BYoesle Post Laureate Reged: 06/12/04 Loc: Washington USA Grand Minimum Ahead?       #5615714 - 01/10/13 03:17 PM Attachment (21 downloads) Edit   Reply   Quote Quick Reply   Recent solar activity cycles have shown a double peak in sunspot numbers link - but??? Quote: Waiting for solar fireworks to reach a grand finale next year [2013]? Um, sorry, looks like you already missed them. Structures in the sun's corona indicate that the peak in our star's latest cycle of activity has been and gone, at least in its northern hemisphere. The southern hemisphere, meanwhile, is on a sluggish rise to solar maximum and may not hit its peak until 2014. Such a large asymmetry between hemispheres could be a sign of big changes ahead, says Steven Tobias, a mathematician at the University of Leeds, UK, who models what drives the sun's magnetic field. According to his models, such a situation precedes an extended quiet phase called a grand minimum. "Changes in symmetry are more indicative of going into a grand minimum than the strength of the cycle," he says. Grand minima can last for decades. The previous one took place between 1645 and 1715, and has been linked to the little ice age in Europe. A new one might also cause localised cold periods, but many climate scientists see a silver lining to such a turn of events: a grand minimum offers ideal conditions for testing the effects of solar variability on Earth's climate... But Michael Proctor, a solar physicist at the University of Cambridge, is not convinced that this will happen. "This present cycle is similar to the weak one that ended in 1913, and that was followed by a strong cycle," he says. Only time will tell. Full New Scientist Sept. 26, 2012 article (linked from the National Solar Observatory): web page Sunspot cycle and double peak graphics sourced from nasa.gov: Post Extras:       JeanB Pooh-Bah Reged: 07/11/11 Loc: Montreal, Canada Re: Grand Minima Ahead? [Re: BYoesle]       #5615804 - 01/10/13 04:08 PM Edit   Reply   Quote Quick Reply   Dang! It is a sad story. I bought my Lunt in 2012. Jean Post Extras:       Andy Devey Carpal Tunnel Reged: 05/06/11 Re: Grand Minima Ahead? [Re: JeanB]       #5615941 - 01/10/13 05:43 PM Edit   Reply   Quote Quick Reply   I wonder if the Sun is also affected by this recession? Regards Andy Post Extras:       bill1234 professor emeritus Reged: 04/21/11 Loc: NJ, USA Re: Grand Minima Ahead? [Re: Andy Devey]       #5615975 - 01/10/13 06:10 PM Edit   Reply   Quote Quick Reply   Bob, you are the man...thank for all your input to this forum. Post Extras:       dscarpa Carpal Tunnel Reged: 03/15/08 Loc: San Diego Ca. Re: Grand Minima Ahead? [Re: BYoesle]       #5615976 - 01/10/13 06:11 PM Edit   Reply   Quote Quick Reply   A Grand Minima might slow down global warming. David Post Extras:       raylal Pooh-Bah Reged: 04/19/10 Loc: Cornwall, Ont., Canada Re: Grand Minima Ahead? [Re: dscarpa]       #5616156 - 01/10/13 07:47 PM Edit   Reply   Quote Quick Reply   I just hope these predictions are wrong. Ray Post Extras:       George9 super member Reged: 12/11/04 Re: Grand Minima Ahead? [Re: raylal]       #5616306 - 01/10/13 09:34 PM Edit   Reply   Quote Quick Reply   Bob, is that related to this story from last year: Sun Headed Into Hibernation, Solar Studies Predict? It says that the something called torsional oscillations for the next cycle should have been visible by now but weren't as of the story (the current cycle's oscillations first started in 1997). I don't see a mention in the new story or a follow up on the Web. This may be the original paper. George Post Extras:       BYoesle Post Laureate Reged: 06/12/04 Loc: Washington USA Re: Grand Minima Ahead? [Re: George9]       #5616551 - 01/11/13 12:37 AM Edit   Reply   Quote Quick Reply   Hi George, I do think they are all inter-related indicators. This latest model/study builds a fourth indicator - increasing north south activity asymmetry - to the previous three. This Sky & Telescope article from last year also covered the three indicators of possible decreased activity well, and has some good graphics: http://www.skyandtelescope.com/news/123844859.html The first issue is the failure to appear of the torsional oscillations - also known as the deep solar jet streams - predicted to be required for there to be a Cycle 25. The second issue cited previously was the weakened and slowed movement of coronal magnetic fields and coronal crown prominences moving towards the poles. The third issue is the decreasing intensity of the magnetic fields within sunspots themselves. Once the field strength falls below 1500 gauss, sunspots will no longer form. If the trend line continues uninterrupted, this will occur about 2022. However, this new hypothesis presupposes that the increased delay between north-south sunspot activity may also predict a decrease in or disappearance of solar activity in the next cycle. So while they are related, it is the asymmetry between north and south sunspot peaks which is the new feature proposed to herald a decrease in solar activity. Thanks for the compliment Bill - I’m just a curious person - that’s all... And not to fear my friends - I prefer to see the glass half-full: If these predictions do came to pass, those of us with H alpha equipped telescopes will be the only ones seeing any solar activity - even though the sun may be completely devoid of spots - while solar physicists will have a heyday of trying to figure out what is going on, and why... Post Extras:       astronz59 sage Reged: 09/15/10 Loc: Auckland, New Zealand Re: Grand Minimum Ahead? [Re: BYoesle]       #5616628 - 01/11/13 03:18 AM Edit   Reply   Quote Quick Reply   Gentlemen, here's a link to an article posted on NASA Science you might find interesting....http://science.nasa.gov/science-news/science-at-nasa/2013/08jan_sunclimate/ Post Extras:       BYoesle Post Laureate Reged: 06/12/04 Loc: Washington USA Re: Grand Minimum Ahead? [Re: astronz59]       #5617297 - 01/11/13 01:35 PM Edit   Reply   Quote Quick Reply   That's an excellent article astron59! I'm reposting the link so others can get to it more easily: link Post Extras:       marktownley Postmaster Reged: 08/19/08 Loc: West Midlands, UK Re: Grand Minimum Ahead? [Re: BYoesle]       #5618467 - 01/12/13 05:10 AM Edit   Reply   Quote Quick Reply   Interesting set of articles. Thanks Post Extras:       Pages: 1

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