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Atraveller
2007-Nov-12, 11:18 PM
It is solar minimum and cycle 24 may not actually start until March of 2008, but when was the last time the sun was this quiet for this long? There have been no sunspots for more than three months. Last time the sun was this quiet for this long was back in the 1600's...

Has anyone got better information than is published at:
http://www.spaceweather.com/
http://sohowww.nascom.nasa.gov/
http://sidc.oma.be/index.php
(?)

Any theories/speculation as to the meaning of the quiet sun?

Superluminal
2007-Nov-13, 02:54 AM
There have been some predictions that the Sun may experiance another Maunder Minimum similar to the one that brought on the Little Ice Age in the 17th-18th century. But the predictions I've read don't expect one until later this century. But I don't think it is unusual for the Sun to go for several months with no spots around the minimum, give it a few months.

novaderrik
2007-Nov-13, 03:09 AM
ok now, everyone sing along..

It's the end of the world as we know it...

NiteWatcher
2007-Nov-13, 03:22 AM
Last time the sun was this quiet for this long was back in the 1600's...

Actually, much later. This is typical of the wax and wane of the Sun, and isn't alarming, unless it happens of an extended period (more than a couple of years).

To me, I hope the sunspots don't come back for about 10 years, because I would love too see how it can influence the climate via observational evidence not politics. ;)

[...Donning Nomex and Kevlar...]

William
2007-Nov-13, 04:48 AM
Issues with solar cycle 23?

This is a good link if you would like a day by day solar update. There is also a graphical comparison of solar cycle 23 to other cycles.

http://www.dxlc.com/solar/

As no one has observed the change to a Maunder minimum so there are many unknowns. I have been following Solar cycle 23 for the last couple of years. The following is some of what I have found.

A prediction based on past solar behaviour that solar cycle 23 should have ended in August, 2006.


Based on the last 12 cycles, "large cycles usually start early", Hathaway told New Scientist. He expects the cycle to begin in late 2006 or early 2007: "We're anxiously awaiting the appearance of those first spots in the new cycle."


http://science.nasa.gov/headlines/y2006/15aug_backwards.htm


http://science.nasa.gov/headlines/y2..._longrange.htm


The following is an excerpt from the above link:

The sun's "Great Conveyor Belt"


" Normally, the conveyor belt moves about 1 meter per second—walking pace," says Hathaway. "That's how it has been since the late 19th century." In recent years, however, the belt has decelerated to 0.75 m/s in the north and 0.35 m/s (has recently slowed down to 0.25 m/s – my comment) in the south. "We've never seen speeds so low."

The above comment concerning the slowing of the solar conveyor belt was made May, 2006. Hathaway, later in 2007 notes the sun is no longer cycle rules.

The following is a 2004 paper that predicts the sun is heading towards a Maunder minimum based on an analysis of the paleo record of solar activity.

http://adsabs.harvard.edu/abs/2004ApJ...605L..81B


We have examined the long-term trends in the solar variability that can be deduced from some indirect data and from optical records. We analyzed the radiocarbon measurements for the last 4500 years, based on dendrochronology, the Schove series for the last 1700 years, based on auroral records, and the Hoyt-Schatten series of group sunspot numbers. Focusing on periodicities near one and two centuries, which most likely have a solar origin, we conclude that the present epoch is at the onset of an upcoming local minimum in the long-term solar variability. There are some clues that the next minimum will be less deep than the Maunder minimum, but ultimately the relative depth between these two minima will be indicative of the amplitude change of the quasi-two-century solar cycle.

Neverfly
2007-Nov-13, 05:46 AM
There have been some predictions that the Sun may experiance another Maunder Minimum similar to the one that brought on the Little Ice Age in the 17th-18th century. But the predictions I've read don't expect one until later this century. But I don't think it is unusual for the Sun to go for several months with no spots around the minimum, give it a few months.

No worries. Global Warming will counter-act it.

dvb
2007-Nov-13, 02:39 PM
Not so good for amateur radio DXing :(

Tunga
2007-Nov-13, 08:48 PM
Where have all the sunspots gone? You must be reading my mind.
http://gcdailyworld.com/story/1290431.html

It will probably be another year before we have a good idea of the intensity of Solar Cycle 24.


No worries. Global Warming will counter-act it.
No that is just an urban legend. Global Warming will not even make a dent.

ctownsoul
2007-Nov-17, 04:08 AM
Finally one is beginning to emerge: http://www.spaceweather.com/images2007/16nov07/midi512_blank.gif

novaderrik
2007-Nov-17, 03:54 PM
Where have all the sunspots gone? You must be reading my mind.
http://gcdailyworld.com/story/1290431.html

It will probably be another year before we have a good idea of the intensity of Solar Cycle 24.


No that is just an urban legend. Global Warming will not even make a dent.

well, we all know what to do..
everyone, to their SUV's and Hummers.. we have a planet to keep warm..

jami cat
2007-Nov-18, 05:35 PM
ok now, everyone sing along..

It's the end of the world as we know it...

I was thinking more of...

Where have all the Sunspots gone...Long time passing...:P
http://www.arlo.net/resources/lyrics/flowers-gone.shtml

Tunga
2007-Nov-20, 05:30 PM
I came across this website which provides interesting insight and analysis on the subject.
http://users.telenet.be/j.janssens/Spotless/Spotless.html#Number
It appears to show that solar cycle 24 will be similar to solar cycles 10-15 rather than solar cycles 16-23.
In that case we might expect 797 +/- 245 spotless sunspot days rather than 362 +/- 134 spotless days (normal for the past century). Over a doubling of spotless days.
This would also correlate to a reduction of approximately 40% in the number of sunspots this cycle.
It seems like we might be going through a state change in the sun that may typify the next 50+ years.

John Kierein
2007-Nov-21, 12:54 PM
Grote Reber (the father of radio astronomy) would have loved this solar minimum. He was able to observe the night sky with his huge array radio telescope at the extremely long wavelengths of hundreds of meters (hectometric). His telescope was in Tasmania where holes opened in the ionosphere during solar minima winters that he could observe through. His best maps were made when the sunspots were gone. His maps are remarkable, showing that the sky is a uniformly bright background with dim spots at the galaxy and Andromeda locations, especially at the galactic center. This clearly indicates that the source of this radiation is from beyond the galaxy or from the intergalactic medium. A popular short description of this is in this:
http://tinyurl.com/yp56ck
Better details are in:
Grote Reber, J.of Franklin Institute, 285, page 1, (1968)
which includes a picture of his array which covered a couple hundred acres and was electronically steerable. Reber became a good friend of mine in the 1980s. I helped get his experiment performed on Spacelab 2 with Dr. Mike Mendillo of Boston U.
http://www.nrao.edu/whatisra/hist_reber.shtml

William
2007-Nov-24, 05:21 AM
Here is another paper that predicts a Maunder minimum. I cannot say whether their solar model is more accurate than others.

As noted above in this thread a period (26 days) without sunspots is not that abnormal. There have however been other observed solar changes which separate cycle 23 from recent cycles.

Excerpt from this paper.

http://adsabs.harvard.edu/abs/2003SPD....34.0603S


Long-range (my comment: solar forecasts)….vary greatly in their methods. They range from examining planetary orbits, to spectral analyses ….to artificial intelligence methods, to simply using general statistical techniques. Rather than concentrate on statistical…. methods, we discuss a class of methods which appears to have a "physical basis." Not only does it have a physical basis, but this basis is rooted in both "basic" physics (dynamo theory), but also solar physics …

My colleagues and I have …expanded the prediction methods using "solar dynamo precursor" methods, …These methods are now based upon an understanding of the Sun's dynamo processes- to explain a connection between how the Sun's fields are generated and how the Sun broadcasts its future activity levels to Earth. This has led to better monitoring of the Sun's dynamo fields and is leading to more accurate prediction techniques. Related to the Sun's polar and toroidal magnetic fields, we explain how these methods work, past predictions, the current cycle, and predictions of future of solar activity levels for the next few solar cycles.

The surprising result of these long-range predictions is a rapid decline in solar activity, starting with cycle #24. If this trend continues, we may see the Sun heading towards a "Maunder" type of solar activity minimum - an extensive period of reduced levels of solar activity.

John Kierein
2007-Dec-06, 12:36 PM
Looks like it may be the end of the solar minimum after a prolonged VERY quiet period with NO sunspots.. Now getting solar x-ray activitiy and there MAY be as many as 3 sunspots. 12-06-07.
Maybe a "dead cat bounce"?

William
2007-Dec-08, 08:07 PM
A) Solar dead cat bounce

I believe the sunspots for the next cycle appear mid latitude on the sun at 45 to 30 degree North or 45 to 30 degree latitude South (and have reversed polarity as compared to the last cycle) rather than at the solar equator. The reversed sunspots for the next cycle are also small and can be difficult to detect. One of these equatorial sunspots is large and could have an associated flare.

Comment concerning NASA Solar Prediction Group
NASA’s solar cyclic prediction panel, have not changed from their March, 2007 prediction. One half of the NASA solar cycle prediction panel predicted that cycle 24 would be a moderately high cycle and the other half of the panel predicted a low activity cycle. Both groups predict cycle 24 will start some time between April 2007 and March 2008. An update from the panel was due October, 2007 but was not provided because there was no change in their prediction.

This is interesting concerning what percentage of time the sun spends in maximums and minimums.

B) Solar history of maximums and minimums
http://cc.oulu.fi/~usoskin/personal/aa7704-07.pdf

This paper provides an overview of the solar maximum and minimum over the last 11,000 years. I had heard that the 20th century level of solar activity is the highest in 11,000 years. Usoskin, Solanki, and Kovaltsov’s paper puts that in perspective. (See figure 3 in the above linked paper.)

The sun is currently in a grand maximum, which Solanski’s defines as a smoothed sunspot number greater than 50. The sun has had 19 great maximum in the 11,000 years and has spent 1000 years or 9% of the 11,000 year period in grand maximum.

Based on the Usoskin et al’s data and definition, in the last 11,000 years the sun has had 27 grand minimums which lasted from 20 to 160 years. The sun has spent 1880 years in grand minimum, 16.8% of the 11,000 year period.

George
2007-Dec-10, 04:11 PM
They're back! (http://sohowww.nascom.nasa.gov/sunspots/). [Dec. 10, 2007] I like this color image best. :)

DyerWolf
2007-Dec-10, 05:37 PM
Originally Posted by Neverfly
No worries. Global Warming will counter-act it.

No that is just an urban legend. Global Warming will not even make a dent.

So, we can anticipate very cold weather?

AWESOME!

I can't wait to ski to work.

HypothesisTesting
2007-Dec-12, 09:09 PM
There have been some predictions that the Sun may experiance another Maunder Minimum similar to the one that brought on the Little Ice Age in the 17th-18th century. But the predictions I've read don't expect one until later this century. But I don't think it is unusual for the Sun to go for several months with no spots around the minimum, give it a few months.

I noticed about a few month lull last solar minimum (I think that was about 1995 or 96 but the years are blurring together..) so I don't think it's unusual

A question for anyone on BAUT: why is the solar cycle linked to climate change? I don't understand this. Is it something as simple as:
more sunspots: more flares: more solar energy intersecting planets
less sunspots: opposite, and climate cool down?:confused:

George
2007-Dec-13, 02:50 AM
I noticed about a few month lull last solar minimum (I think that was about 1995 or 96 but the years are blurring together..) so I don't think it's unusual.
This NOAA site (http://www.sec.noaa.gov/SolarCycle/) shows the monthly sunspot count and the projected count. Notice that we are now at the minimum.


A question for anyone on BAUT: why is the solar cycle linked to climate change? I don't understand this. Is it something as simple as:
more sunspots: more flares: more solar energy intersecting planets
less sunspots: opposite, and climate cool down?:confused: These and espeically the change in the magnetic field are contributing factors. It is not yet established whether these really have that much impact on our weather. The curious story rests with the Maunder Minimum when it got cold during a time of very little Solar activity.

Kaptain K
2007-Dec-13, 03:40 AM
IIRC, the "Little Ice Age ended with the beginning of the Maunder Minimum.

Superluminal
2007-Dec-13, 03:47 AM
No, I believe the LIA began with the Maunder Minimum.

Also, the MM lasted about 75 years, plenty of time for the decrease in solar activity to affect the climate. The normal solar minimum is just a few years.

Kaptain K
2007-Dec-13, 04:09 AM
That'll teach me to Google first, then post!
I stand corrected! :rolleyes:

Tunga
2007-Dec-14, 08:44 PM
A question for anyone on BAUT: why is the solar cycle linked to climate change? I don't understand this.

The answer is related to the latest research from the Danish National Space Center among others.
http://www.innovations-report.de/html/berichte/physik_astronomie/bericht-71378.html

Our Milky Way galaxy is awash with cosmic rays. These are high speed charged particles that originate from exploding stars. Because they are charged, their travel is strongly influenced by magnetic fields. Our sun produces a magnetic field that extends to the edges of our solar system. This field deflects many of the cosmic rays away from Earth. But when the sun goes quiet (minimal sunspots), this field collapses inward allowing cosmic rays to penetrate deeper into our solar system. As a result, far greater numbers collide with Earth and penetrate down into the lower atmosphere where they ionize small particles of moisture (humidity) forming them into water droplets that become clouds. Low level clouds reflect sunlight back into space. A large increase in Earth's cloud cover produce a global drop in temperature.

Kaptain K
2007-Dec-14, 09:11 PM
Also, the solar output varies (very slightly) with sunspot numbers.

George
2007-Dec-14, 10:15 PM
The answer is related to the latest research from the Danish National Space Center among others.
http://www.innovations-report.de/html/berichte/physik_astronomie/bericht-71378.html


Per the link...


Interestingly, during the 20th Century, the Sun’s magnetic field which shields Earth from cosmic rays more than doubled, thereby reducing the average influx of cosmic rays.
I am unclear on what they are claiming. Was the average mag. field of the Sun double that of prior centuries, or was the variation during the century as much as double the low level?


‘Many climate scientists have considered the linkages from cosmic rays to clouds to climate as unproven,’ comments Eigil Friis-Christensen, who is now Director of the Danish National Space Center. ‘Some said there was no conceivable way in which cosmic rays could influence cloud cover. The SKY experiment now shows how they do so, and should help to put the cosmic-ray connection firmly onto the agenda of international climate research.
I want to say global cloud covering is being monitored from space, but I assume this is a relatively new study. If these results correlate directly with the sunspot cycle, then they would be very strong support to further the claim.

Tunga
2007-Dec-15, 03:20 AM
I want to say global cloud covering is being monitored from space, but I assume this is a relatively new study. If these results correlate directly with the sunspot cycle, then they would be very strong support to further the claim.

Actually, this research has been going on for over a decade. Refer to this paper. http://www.dsri.dk/~hsv/9700001.pdf
Figure 1 shows how the cosmic ray flux changes over several solar cycles.
Figure 4 shows how cosmic ray flux correlates to ocean cloud cover.


I am unclear on what they are claiming. Was the average mag. field of the Sun double that of prior centuries, or was the variation during the century as much as double the low level?

This is a comparison of sunspot activity (a measure of the suns magnetic field strength) from the 20th century compared to prior centuries. A good visual is in the link provided by William. Refer to Figures 1, 3 and 4 in the following paper http://cc.oulu.fi/~usoskin/personal/aa7704-07.pdf

George
2007-Dec-15, 07:48 PM
Actually, this research has been going on for over a decade. Refer to this paper. http://www.dsri.dk/~hsv/9700001.pdf
Figure 1 shows how the cosmic ray flux changes over several solar cycles.
Figure 4 shows how cosmic ray flux correlates to ocean cloud cover. Nice.


This is a comparison of sunspot activity (a measure of the suns magnetic field strength) from the 20th century compared to prior centuries. A good visual is in the link provided by William. Refer to Figures 1, 3 and 4 in the following paper http://cc.oulu.fi/~usoskin/personal/aa7704-07.pdf
Wow. That is quite a surprising a magnetic flux variation. It suggests it has been 10 fold many times over the last several thousand years. Considering how stable the sp. irr. of the Sun is, especially in the visible range, it is a little hard to imagine a mag. flux variation of that magnitude. This flux is in the 1014 Weber range, too. Thanks.

William
2007-Dec-17, 03:36 AM
In reply to HypothesisTesting “A question for anyone on BAUT: why is the solar cycle linked to climate change? I don't understand this. Is it something as simple as: more sunspots: more flares:”

Hi H.T. This is my attempt to answer your question.

The sun changes planetary temperature directly by changes in the TSI and UV and indirectly by modulating the amount of planetary cloud cover.

The sun is hypothesized to modulate planetary cloud cover by two mechanisms.

1) Solar Heliosphere Modulation of GCR
Changes in the sun are hypothesized to modulating the amount of galactic cosmic rays (GCR) that strikes the earth’s atmosphere. GCR (or more correctly muons which are created when the high speed mostly protons strike the atmosphere) have been shown to create cloud forming nucleus, so more GCR more clouds and visa versa. As clouds reflect roughly 22% of the light from the sun back up to space, more or less clouds changes planetary temperature.

It is not the sun, but the solar heliosphere that blocks the GCR. The heliosphere is conductive, a plasma that carries pieces of the solar magnetic field out into space, to about the orbit of Neptune.

2) Solar High Speed Winds removing Cloud Forming Ions: Electroscavenging Mechanism

High speed solar wind bursts create a charge in the earth’s ionosphere which removes cloud forming ions. The high speed solar wind bursts occur when coronal holes move into an earth facing position.

It is not the number of sunspots but rather the properties of the heliosphere (magnitude of the solar wind and the number and magnitude of magnetic flux that moves into the heliosphere, which determines how effective the heliosphere is in blocking GCR. Sunspot number is somewhat correlated to the specific changes in the heliosphere. A better parameter is ak which is a measurement of the change in the geomagnetic field by solar field changes.

The electroscavenging mechanism is dependent on the magnitude and number of the solar wind bursts which has been found to be related to solar cycle length. (See Georgieva et als paper that 20th century solar changes and correlation to planetary temperature changes.)

Comment:
In addition to the short term solar modulation of GCR (10 to 160 yr solar changes), GCR also varies depending on the position of the solar system in galaxy. When the solar system passes through the galactic arms there is roughly 10 times more GCR than when the solar system moves outside the galactic plane. This large long term change in GCR is hypothesized to cause the ice epochs. (See Nir Shaviv’s papers.)

Here are a couple of recent papers.

“Atmospheric Ionization and Clouds as Links between Solar Activity and Climate”
By Brian Tinsley and Fangqun Yu

This paper is a good over view of the mechanisms.

http://www.utdallas.edu/physics/pdf/Atmos_060302.pdf

"On climate response to changes in the cosmic ray flux and radiative budget" by Nir Shaviv.

http://arxiv.org/pdf/physics/0409123

Celestial driver of Phanerozoic climate? Nir Shaviv & Ján Veizer,

http://www.phys.huji.ac.il/~shaviv/Ice-ages/GSAToday.pdf

“Once again about global warming and solar activity” by Georgieva, Bianchi, & Kirov
http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf

William
2007-Dec-21, 05:09 AM
Solar cycle 24 started?

http://www.physorg.com/news117121262.html


The region that appeared on Dec. 11th fits both these criteria. It is high latitude (24 degrees N) and magnetically reversed. Just one problem: There is no sunspot. So far the region is just a bright knot of magnetic fields. If, however, these fields coalesce into a dark sunspot, scientists are ready to announce that Solar Cycle 24 has officially begun.

William
2007-Dec-30, 06:08 PM
I was reviewing information concerning the geomagnetic field and found this link which shows how solar magnetic storms affect the earth’s ionosphere.

(The solar wind bursts associated with solar magnetic storms, cause an increase in the global electric current. The increase in the global current it is hypothesized by Tinsley to remove cloud forming ions. A reduction in planetary cloud cover, particularly over the oceans would make the planet warmer. Oceans act as a heat sink and there is a deficiency of cloud forming ions over the oceans, as compared to the continents.)

Look at figure 9 in the attached which shows the number of solar magnetic storms per year, from 1868 to present and the corresponding number of sunspots. There is a roughly 20 times increase in the number of magnetic storms at the end of the solar cycles, when comparing the 20th century to the 19th century. The number of solar magnetic storms appears to be a better indicator than the number of sunspots, to the hypothesized solar climate modulation mechanisms.

http://www.geomag.bgs.ac.uk/earthmag.html#_Toc2075558

Comments:
The change in the number of solar magnetic storms (at the end of the solar cycle) would explain why the climate change from solar maximum to solar minimum has not as significant in the 20th century (in some cases there were peaks in planetary temperature at the end of the solar cycle.). In the 19th century, the solar cycle (based on the hypothesized mechanisms) would have had a stronger affect on planetary temperature (i.e. There would have been cooling at the end of the cycle.) In the 19th century it was noted, by those living at the time, that the price of wheat tracked the solar cycle. (Cooler, wetter weather at the end of the solar cycle in the 19th century.)

No new, news concerning solar cycle 23. Sun is currently spotless.

George
2008-Jan-01, 09:13 PM
Solar cycle 24 started?

They'll be coming around the limb when they come (http://sohowww.nascom.nasa.gov/data/realtime/mdi_igr/512/),
They'll be coming around the limb when they come, (http://sohowww.nascom.nasa.gov/data/realtime/mdi_mag/512/)
They'll be coming around the limb, they'll be coming around the limb,
They'll be coming around the limb when they come.

They are mid-lattitude, however.