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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Grand Minimum Ahead?
      #5615714 - 01/10/13 03:17 PM Attachment (37 downloads)

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:


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JeanB
Pooh-Bah


Reged: 07/11/11

Loc: Montreal, Canada
Re: Grand Minima Ahead? new [Re: BYoesle]
      #5615804 - 01/10/13 04:08 PM

Dang! It is a sad story. I bought my Lunt in 2012.

Jean


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Andy Devey
Carpal Tunnel


Reged: 05/06/11

Re: Grand Minima Ahead? new [Re: JeanB]
      #5615941 - 01/10/13 05:43 PM

I wonder if the Sun is also affected by this recession?

Regards

Andy


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bill1234
professor emeritus


Reged: 04/21/11

Loc: NJ, USA
Re: Grand Minima Ahead? new [Re: Andy Devey]
      #5615975 - 01/10/13 06:10 PM

Bob, you are the man...thank for all your input to this forum.

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dscarpa
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Reged: 03/15/08

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Re: Grand Minima Ahead? new [Re: BYoesle]
      #5615976 - 01/10/13 06:11 PM

A Grand Minima might slow down global warming. David

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raylal
Carpal Tunnel


Reged: 04/19/10

Loc: Cornwall, Ont., Canada
Re: Grand Minima Ahead? new [Re: dscarpa]
      #5616156 - 01/10/13 07:47 PM

I just hope these predictions are wrong.

Ray


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George9
sage


Reged: 12/11/04

Re: Grand Minima Ahead? new [Re: raylal]
      #5616306 - 01/10/13 09:34 PM

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


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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Re: Grand Minima Ahead? new [Re: George9]
      #5616551 - 01/11/13 12:37 AM

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...


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astronz59
sage


Reged: 09/15/10

Loc: Auckland, New Zealand
Re: Grand Minimum Ahead? new [Re: BYoesle]
      #5616628 - 01/11/13 03:18 AM

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/

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BYoesle
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Reged: 06/12/04

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Re: Grand Minimum Ahead? new [Re: astronz59]
      #5617297 - 01/11/13 01:35 PM

That's an excellent article astron59!



I'm reposting the link so others can get to it more easily:

link


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marktownley
Postmaster


Reged: 08/19/08

Loc: West Midlands, UK
Re: Grand Minimum Ahead? new [Re: BYoesle]
      #5618467 - 01/12/13 05:10 AM

Interesting set of articles. Thanks

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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Re: Grand Minimum Ahead? new [Re: marktownley]
      #6089773 - 09/19/13 11:29 AM Attachment (10 downloads)

The latest Sky & Telescope article on solar activity and the developing prediction for Cycle 25:

Quote:

Regardless of what’s causing the Sun’s strange behavior, Hathaway and Penn, who are both in the solar prediction business, anticipate that Cycle 25, expected to peak in 2024, will be the weakest yet... Penn’s prediction is based on the weakening magnetic field he sees within sunspots; Hathaway’s are instead based on measurements of the Sun’s polar field and the meridional flow, the flow of magnetic flux from the Sun’s equator to the poles. A stronger flow would help strengthen weak fields, but meridional flows have been completely absent in Cycle 24 so far. Empahsis added.




Full article here: http://www.skyandtelescope.com/news/The-Weakest-Solar-Cycle-in-100-Years-2167...


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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Re: Grand Minimum Ahead? new [Re: BYoesle]
      #6089786 - 09/19/13 11:39 AM Attachment (9 downloads)

Sunspot field strength though 2012:

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PatHolland
Carpal Tunnel
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Reged: 10/11/09

Loc: Clever, Missouri
Re: Grand Minimum Ahead? new [Re: BYoesle]
      #6089881 - 09/19/13 12:41 PM

Very interesting yet sad info. Thanks Bob for bringing up the discussion. White light and CAK modules may end up in storage (possibly a time capsule) if the scientific prediction holds.

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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Re: Grand Minimum Ahead? new [Re: PatHolland]
      #6089904 - 09/19/13 12:51 PM Attachment (9 downloads)

It's looking more likely as Cycle 24 goes on that amateur solar activity for the foreseeable future will be more limited to H alpha equipped telescopes... but I'm still keeping My WL and CaK equipment up and running no matter what. Indeed, the design and building of a solar patrol telescope scope is underway

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ValeryD
Vendor (Aries)
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Reged: 11/26/05

Loc: Kherson, Ukraine.
Re: Grand Minima Ahead? new [Re: BYoesle]
      #6091002 - 09/20/13 02:01 AM

Quote:



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...




Very true!

And the best one can do is to prepare as large solar scopes he can afford. As larger the aperture - as more small scale events can be observed. I personally will prepare a really big solar telescope with subaperture H-a filter.


Valery.


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HPaleske
professor emeritus


Reged: 04/09/07

Re: Grand Minima Ahead? new [Re: ValeryD]
      #6091576 - 09/20/13 11:43 AM

Bob,

I'm curious to see if your solar telescope design works.

One more question.

With aperture ratio works your solar telescope? The etalons require an aperture ratio of at least 1:30.


Cs Harald
www.unigraph.de


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BYoesle
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Reged: 06/12/04

Loc: Goldendale, Washington USA
Re: Grand Minima Ahead? new [Re: HPaleske]
      #6093235 - 09/21/13 11:29 AM

Hi Harald. Mine is a collimator based system -- not a telecnetric. The light passed through the filter is therefore rendered "parallel" via the colimator lens, and is not subject to the f30 requirement for proper etalon performance.

The EFL of the final image is 1500 mm, making the overall system f10.

I will hopefully be able to post a more detailed description of the design as it progress...

In the meantime, let's hope the sun cooperates at least a little in the years ahead!


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BYoesle
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Reged: 06/12/04

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Re: Grand Minima Ahead? new [Re: BYoesle]
      #6132951 - 10/12/13 12:13 PM

Sky and Telescope recently reported there is new helio-seismic findings from the SDO showing current theories of solar magnetic flows are in need of revision, and which may help eventually to understand the inner workings of the sun and the variability of the sunspot cycle.

The new findings indicate there are actually two circulation cells in the solar interior... I wonder if perhaps this might result at times in the circulations cancelling each other out, and which might cause the decreased activity now being observed (and observed in the past)...???

Quote:

David Hathaway (Marshall Space Flight Center), who has done extensive research on the meridional flow and its role in predicting the solar cycle, says the results are “catastrophic” for current theory. “It indicates the need for revolutionary changes in our dynamo models for the sunspot cycle.”




See: http://www.skyandtelescope.com/news/Glimpse-of-Suns-Interior-Befuddles-Theori...


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