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Thread: Solar cycle #24

  1. #211
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    Quote Originally Posted by aurora View Post
    I'd be interested to know a proposed mechanism that would cause this to happen.

    I'd have assumed that any direct impacts on Earth would be climatic in nature.
    More observations are required to determine if this truly is an abrupt interruption of the solar magnetic cycle and if it is, what impact this change will have on the planet.

    It is possible based on what has happened in the past to estimate what on the planet would be impacted and the possible magnitude of the related problems.

    The past observational data supports the hypothesis that the fundamental mechanisms have in the past resulted in abrupt drops in planetary temperature. (i.e. The earth based planetary record shows cyclic abrupt drops in planetary temperature and very large short term and long term changes in the geomagnetic field. What is missing is the discovery of the mechanism that causes the observed changes.)

    I have included in this comment a link to an interesting review article on the solar magnetic cycle and the Maunder minimum and other Maunder like minimums.

    The affects will be (Assuming the past abrupt changes in the cosmogenic isotopes that are deposited in sea floor sediment and ice sheets where caused by a similar solar cycle magnetic cycle interruption and assuming the past abrupt drops in planetary temperature where caused by the solar magnetic cycle interruption (which would explain why there is time and time again correlation in time between the abrupt drops in temperature and abrupt changes in the cosmogenic isotopes that are created at the time of the abrupt planetary temperature changes), and assuming the evidence that the geomagnetic field intensity abruptly drops and changes cyclically is correct and is cause by something that is related to/connected to a sever solar magnetic cycle interruption.): climatic (An abrupt drop in planetary temperature), sever damage to planetary electrical infrastructure (generator and transformer damage), and sever damage to satellite communication.


    http://cc.oulu.fi/~usoskin/personal/Miyahara_AG06.pdf

    In principle, one could suppose that the occurrence of a Grand minimum can be related to a suppression of sunspot formation without changing the dynamo mechanism itself. This possibility is unfavorable for dynamo interpretation and can be declined because of the fact that the magnetic activity recovery was strongly asymmetric at the end of the MM46 (see Sec. 2.1). This argument is however not completely decisive because of the threshold nature of sunspot formation, which could amplify a small random North–South asymmetry of the toroidal magnetic field to a seemingly asymmetric butterfly diagrams. The pattern followed from cosmogenic isotope data and auroral records during the MM (Sec. 2.2) rejects this interpretation on a more solid way. This indicates that not only sunspot formation but also the global solar/interplanetary magnetic field was reduced during the MM.
    Some estimates of the heliospheric parameters have been performed based on the available data sets discussed above. It is supposed 52–54 that the solar wind was significantly slower during the MM, 200–350km/s, compared to the presently measured 400–800km/s. The interplanetary magnetic field (actually its Bz component)54 and the axial dipole strength55 were also estimated to be essentially lower (by a factor 4–7) than presently. Applying a heliospheric model of cosmic ray transport to the measured 10Be in polar ice, Scherer et al.56,57 have shown that the diffusion coefficient of cosmic rays in the heliosphere should be increased during the MM, which implies decreased level of the interplanetary magnetic field and/or interplanetary turbulence. However, these numbers were obtained using regression or other models based on sunspot numbers and fitted to modern conditions and, therefore, can be considered only as rough estimates.

    A particular scheme of solar dynamo suggests a physical mechanism connecting toroidal and poloidal magnetic fields. An obvious way to obtain toroidal magnetic field from poloidal one is the solar differential rotation. It is, however, much more difficult to obtain BP from BT. Parker39 suggested that this can be done by means of cyclonic motions in the solar convective zone. A joint action of Coriolis force and density gradients results in an excess of right-hand vortices in one hemisphere and left-hand vortices in the other hemisphere. In turn, a component of the mean magnetic field B parallel to the mean electric current J appears due to this excess. A consistent theory of this effect was developed in 1960s by Krause and R¨adler40 who used the notation α for the proportionality coefficient between B and J. This effect is known now as the α-effect. This scheme results in self-excitation of a dynamo wave similar to that one known from observations.
    The toroidalmagnetic fields in Northern and Southern solar hemispheres usually have opposite polarities. This toroidal magnetic field configuration is referred to by theoreticians as dipolar. The Maxwell equations admit however another configuration with the toroidal magnetic field of the same polarity in both hemispheres, which is called quadrupolar configuration. In practice, phases of the dynamo waves propagating through Northern and Southern hemisphere can be shifted in respect to each other. This displacement can be presented as an admixture of the quadrupole configuration with the dipole.41

    The toroidal magnetic field is hidden inside the solar convective zone and is inaccessible for direct observation. Fortunately, the toroidal magnetic field can be traced by sunspots. On one hand, the sunspots are not an inevitable component of solar dynamo. One can imagine a star with a dynamo wave propagating somewhere inside the convective zone where due to some reason the sunspot production is strongly suppressed. It would be very difficult to recognize the existence of toroidal magnetic field on such a star. In contrast, poloidal magnetic field is present on the solar surface directly. On the other hand, the toroidal magnetic field inside the Sun known via sunspot data is much more intense than the relatively weak poloidal magnetic field. The most spectacular data concerning solar and stellar activity cycles are indirect and represent the toroidal magnetic field behavior.

    Direct data related to the poloidal magnetic field behavior are more obscure. As a matter of fact, comparisons between dynamo models and observations are based mainly on sunspot data. Cosmogenic isotope data are particularly important because they reflect properties of the poloidal magnetic field, i.e., they are complementary to the sunspot data.

  2. #212
    Just as a very basic question, do we know anything about the sunspot cycles or magnetic fields of other stars? Is the magnetic reversal something that happens to all stars, or a class of stars? And also, do stars like the sun also have phases like "Maunder minimums?" I'm basically not sure how much detail we know about the behavior of other stars.
    As above, so below

  3. #213
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    Quote Originally Posted by Jens View Post
    Just as a very basic question, do we know anything about the sunspot cycles or magnetic fields of other stars? Is the magnetic reversal something that happens to all stars, or a class of stars? And also, do stars like the sun also have phases like "Maunder minimums?" I'm basically not sure how much detail we know about the behavior of other stars.
    Hi Jens,

    It does appear all stars have magnetic fields and magnetic field cycles. There is evidence of Maunder minimums for solar like stars.

    The great distance to other stars, however, reduces the type of data that is available to study the star.

  4. #214
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    NASA have updated their request for research proposals for the cycle 24 anomaly.

    http://nspires.nasaprs.com/external/...CCMSC%20v3.pdf

    B.9 CAUSES AND CONSEQUENCES OF THE MINIMUM OF SOLAR CYCLE 24
    Clarified May 5, 2009: This opportunity solicits proposals to study the causes and consequences of the minimum in solar activity that began in 2007 and persists to date. The solicitation is focused on understanding the causes and/or consequences of this particular time period. ...
    In 2009, we are in the midst of the minimum of solar activity that marks the end of Solar cycle 23. As this cycle comes to an end we are recognizing, in retrospect, that the Sun has been extraordinarily quiet during this particular Solar Cycle minimum. This is evidenced in records of both solar activity and the response to it of the terrestrial space environment. For example:

    Causes – Solar output
    • Lowest sustained solar radio flux since the F 10.7 proxy was created in 1947;
    • Solar wind global pressure the lowest observed since the beginning of the Space age;
    • Unusually high tilt angle of the solar dipole throughout the current solar minimum;
    • Solar wind magnetic field 36% weaker than during the minimum of Solar Cycle 22/23;
    • Effectively no sunspots;
    • The absence of a classical quiescent equatorial streamer belt; and
    • Cosmic rays at near record-high levels.

    Consequences
    • With the exception of 1934, 2008 had more instances of 3-hr periods with Kp=0 than any other year since the creation of the index in 1932;
    • Cold contracted ionosphere and upper atmosphere; and
    • Remarkably persistent recurrent geomagnetic activity.

  5. #215
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    Quote Originally Posted by Jens View Post
    ...do we know anything about the sunspot cycles or magnetic fields of other stars? Is the magnetic reversal something that happens to all stars, or a class of stars? And also, do stars like the sun also have phases like "Maunder minimums?"
    Here is an abstract from a paper summarizing the reclassifications of supposed Maunder minimum stars as older, more evolved stars that are above the main sequence and therefore not like the Sun. In fact, when stars become old enough, their magnetic fields shut down all together.

    You can read the paper in it's entirety here. From the conclusion of the paper: "To date, there is no unambiguous identification of another star in a Maunder minimum state. "

  6. #216
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    Quote Originally Posted by William View Post
    More observations are required to determine if this truly is an abrupt interruption of the solar magnetic cycle and if it is, what impact this change will have on the planet.

    It is possible based on what has happened in the past to estimate what on the planet would be impacted and the possible magnitude of the related problems.

    The past observational data supports the hypothesis that the fundamental mechanisms have in the past resulted in abrupt drops in planetary temperature. (i.e. The earth based planetary record shows cyclic abrupt drops in planetary temperature and very large short term and long term changes in the geomagnetic field. What is missing is the discovery of the mechanism that causes the observed changes.)
    i think my message was misunderstood.

    The point I was questioning was your assertion that the solar cycle can cause an increase in earthquakes.

  7. #217
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    Quote Originally Posted by William View Post
    It does appear all stars have magnetic fields and magnetic field cycles. There is evidence of Maunder minimums for solar like stars.
    Not all stars have magnetic fields, only stars that have a convective layer, which does not exist in every star.

    Sunspots have been observed on other stars through brightness variations.

    I have never heard about "maunder minimums" on other stars, could you provide some evidence here?

    Some info from Wiki (not THE source for reliable information, but this is not half bad)

    Quote Originally Posted by Wiki(sunspot)
    Periodic changes in brightness had been first seen on red dwarfs and in 1947 G. E. Kron proposed that spots were the cause.[4] Since the mid 1990s observations of starspots have been made using increasingly powerful techniques yielding more and more detail: photometry determined starspot regions grew and decayed and showed cyclic behaviour similar to the Sun's; spectroscopy examined the structure of starspot regions by analyzing the variations in spectral line splitting due to the Zeeman Effect; Doppler imaging showed differential rotation of spots for several stars and distributions different from the Sun's; spectral line analysis measured the temperature range of spots and the stellar surfaces. For example, in 1999, Strassmeier reported the largest cool starspot ever seen rotating the giant K0 star XX Triangulum (HD 12545) with a temperature of 3,500 kelvin, together with a warm spot of 4,800 kelvin.[4][13]
    The only thing about "maunder minima" I found was from the wiki about starspots, which does not really make sense at all, but I will give it anyway:

    Quote Originally Posted by Wiki(starspot)
    Some stars have longer cycles, possibly analogous to the Maunder minima for the Sun.
    Other stars, other dynamos, other dynamics. The fact that the cycle may be longer than the Sun's does not immediately mean it is "maunder minimum", but like I said, it IS wiki ...

    For anyone interested in reading a huge website Svetlana V. Berdyugin wrote one on "Starspots: A key to the stellar dynamo." I have not read it, dunno if it is any good.
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  8. #218
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    Quote Originally Posted by tusenfem View Post
    Not all stars have magnetic fields, only stars that have a convective layer, which does not exist in every star.

    Sunspots have been observed on other stars through brightness variations.

    I have never heard about "maunder minimums" on other stars, could you provide some evidence here?
    Hi tusenfem,

    It appears other stars do have Maunder minimums.

    From what I could find (Comparing observations to theories, it appears there are fundamental issues with the assumed mechanism.) it appears the origin of stellar magnetic fields is not resolved. I have some thoughts concerning fundamental mechanisms. I will start a separate thread, if there is solar cycle 24 data that supports what I believe will unfold.

    It appears sunspots are not generated in the convection zone. The field strength of a sunspot is too strong. The sunspot is believed to be generated in the tachocline.

    I would expect that this issue (what is the mechanism that creates the magnetic fields in stars) will be resolved as solar cycle 24 evolves.

    http://www.stsci.edu/stsci/meetings/lisa3/beckmanj.html

    4. Magnetic Cycles in Late-type Stars: Maunder minima?
    Starting in the 1960's at the Mt. Wilson Observatory O.C. Wilson (sic) began a long-term study of magnetic cycles in cool stars using as his observational indicator the variable emission flux of the H and K resonance lines of ionized calcium whose appearance in emission is characteristic of stellar chromospheres. There is an excess of H and K emission in the faculae which surround sunspots, and epochs of sunspot maximum coincide with epochs of maximum H and K. If the Sun were a distant star, we could observe its 11-year cycle as a variation in integrated H+K flux with this period and with a peak-to-peak amplitude some 30% of the mean. Wilson set out to see whether stars of similar spectral type and luminosity class (i.e. similar surface temperature and mass) show comparable variations. This entailed a major project, the monitoring of the fluxes of a group of stars during decades. Wilson's project was taken up by his students and successors, notably by Vaughan and by Baliunas, with the result that there are now well sampled records of H+K intensity for over a hundred stars covering 30 years, plus samples of many hundreds more, including coeval starclusters, covering the past 15 years. A full summary of the project and its results is given in Baliunas et al. (1998). One of the manifold implications of these results is the possible detection of Maunder minima in Sun-like stars.

    In very broad terms, for two similar stars the one which rotates faster will have a stronger magnetic field, and also stronger H+K emission. Again, in general terms, the older a star the slower it rotates. Thus H+K emission is an indicator of age, and has been calibrated against open stellar clusters, whose ages can be determined via collective photometry of their complete populations. One obvious problem here is that if a star shows H+K variability, with amplitude similar to that of the Sun, say, a single measurement which catches the star at a maximum or minimum will give a misleading age estimate; what is required is a mean over a stellar cycle, or over a long enough period to cover short-term variations. In a cluster these effects can be cancelled even at a single epoch by averaging over its population, but for a single star this is not possible. The situation is worsened if stars have Maunder minima, because a measurement of H+K during a Maunder minimum would give the false impression of very low activity, and very great age. Stars with low activity have indeed been found. A significant fraction, maybe 20% of the isolated solar-type stars of the Mt. Wilson survey have low, constant H+K levels. These might just be very old stars, but a similar situation is found in the stars of the open cluster M 67, which is just a little younger than the Sun.

    This strongly suggests that solar-type stars do go through phases of low magnetic activity, and that these Maunder minima last some 20% of the time. Many doubts remain; only one star has possibly been ``caught'' in transition from low to ``normal'' activity, from a sample for which more than 5 such transitions could be expected during their period of observation. Possibly, the stars with low activity are always like this and are simply slow rotators. Up to now no observable correlation of activity with rotational period has been possible (the periods must be of order weeks or months, which requires extreme spectral resolution to measure). Without going further into detail, the whole question is open and is a subject of active investigation. In particular direct measurements of indices of total stellar luminosity are being taken together with the H+K indices, to see whether, and to what degree, stellar (and thus solar) total power is correlated with magnetic field strength. The solar work gave the first clue, and the stellar work gives a framework to quantify, to predict, and eventually to model theoretically, the behaviour of the Sun.
    http://homepages.uni-tuebingen.de/ma...cospar2004.pdf

    Such a magnetic field cannot be generated within the convection zone, because it would be highly buoyant and rise to the surface too quickly to allow amplification by differential rotation (Parker, 1975). In a thin layer below the convection zone the magnetic field can be stored long enough to allow amplification up to field strengths of about 10 T. Secondly, magnetic pumping provides a mechanism by which weak magnetic fields are advected downward throughout the convection zone until they reach the top of the radiative core (Ossendrijver et al., 2002; Ziegler & Rudiger, 2003). Thirdly, the solar tachocline is also situated near the base of the convection zone, and provides a mechanism to convert a weak poloidal magnetic field into a strong toroidal magnetic field. Fourthly, computations of toroidal magnetic flux tubes rising from a stably stratified region below the convection zone towards the solar surface are able to reproduce different systematic properties of sunspots using only one free parameter, the magnetic field strength, which has to be of the order 10 T (Caligari et al., 1995).

  9. #219
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    Quote Originally Posted by aurora View Post
    i think my message was misunderstood.

    The point I was questioning was your assertion that the solar cycle can cause an increase in earthquakes.
    I have only found one paper that links earthquakes to solar minimums and that paper showed a correlation in one region. The link may, however, be more difficult to make due to the lack of long term earthquake data. I believe there were very large earthquakes during the last solar minimum in the 1970s.

    The link between solar minimum and large volcanic eruptions has been known for sometime, however, there is not agreement on a mechanism.

    I would assume the mechanism is proportional to the length of the solar magnetic cycle and the number of sunspots (before the minimum) and how quickly the change is to the minimum without sunspots. As the sunspot activity in the late 20th century was the highest in 10,000 years and the solar cycles were very short, if the past is a a guide to the future (mechanism still needs to be determined) there may be very large volcanic eruptions, in the next decade.

    As this paper notes, researchers had noted large volcanic eruptions follow cooling periods. The cooling periods also follow solar minimums.

    http://www.sciencemag.org/cgi/conten...t/206/4420/826

    Can Rapid Climatic Change Cause Volcanic Eruptions?
    Many major volcanic eruptions coincide with cooling trends of decadal or longer duration that began significantly before the eruptions. Dust veils provide positive feedback for short-term (less than 10 year) global cooling, but seem unlikely to trigger glaciations or even minor climate fluctuations in the 10-to 100-year range. On the contrary, variations in climate lead to stress changes on the earth's crust—for instance, by loading and unloading of ice and water masses and by axial and spin-rate changes that might augment volcanic (and seismic) potential.
    http://www.agu.org/pubs/crossref/198...12p17371.shtml

    The historical record of large volcanic eruptions from 1500 to 1980, as contained in two recent eruption catalogs, is subjected to detailed time series analysis. Two weak, but probably statistically significant, periodicities of ∼11 and ∼80 years are detected. Both cycles appear to correlate with well-known cycles of solar activity; the phasing is such that the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). The weak quasi-biennial solar cycle is not obviously seen in the eruption data, nor are the two slow lunar tidal cycles of 8.85 and 18.6 years. Time series analysis of the volcanogenic acidities in a deep ice core from Greenland, covering the years 553–1972, reveals several very long periods that range from approx. 80 to 350 years and are similar to the very slow solar cycles previously detected in auroral and carbon 14 records. Mechanisms to explain the Sun-volcano link probably involve induced changes in the basic state of the atmosphere. Solar flares are believed to cause changes in atmospheric circulation patterns that abruptly alter the Earth's spin. The resulting jolt probably triggers small earthquakes which may temporarily relieve some of the stress in volcanic magma chambers, thereby weakening, postponing, or even aborting imminent large eruptions. In addition, decreased atmospheric precipitation around the years of solar maximum may cause a relative deficit of phreatomagmatic eruptions at those times.
    http://www.cfa.harvard.edu/~wsoon/18...er_of_1816.pdf

  10. #220
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    Quote Originally Posted by William View Post
    Hi tusenfem,

    It appears other stars do have Maunder minimums.

    From what I could find (Comparing observations to theories, it appears there are fundamental issues with the assumed mechanism.) it appears the origin of stellar magnetic fields is not resolved. I have some thoughts concerning fundamental mechanisms. I will start a separate thread, if there is solar cycle 24 data that supports what I believe will unfold.

    It appears sunspots are not generated in the convection zone. The field strength of a sunspot is too strong. The sunspot is believed to be generated in the tachocline.

    I would expect that this issue (what is the mechanism that creates the magnetic fields in stars) will be resolved as solar cycle 24 evolves.
    I beg to differ, the process of the solar dynamo is rather well developed. One just has to look this list on ADS to see how much is being worked on the solar dynamo (and planetary dynamos too, actually, which are not in the list). At to become specific this paper by Weiss and Thompson shows that we are not in the dark even on some of the aspects of the 11 year cycle. You always seem to be rather bold in your statements, which are not really supported by what has been published in the scientific literature.

    I am not sure what I should do with the quote texts that you put into your post. It seems to me more like supposition, that "if the star would have a Maunder minimum then ..." Because, what do they have: observations since the 60, that is 50 years, for the Sun that would be less then 5 cycles. How can you, with statistical significance, say that the star is in a minimum, or that the model describing its variation is off?

    And then the 100s of stars have only been observed for 15 years!

    I think the whole website is rather handwaving and apparently a conference proceedings or something like that. According to ADS this idea was never published in any peer reviewed journal (and the website and pdf on it are from 1998!).
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  11. #221
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    Quote Originally Posted by tusenfem View Post
    I beg to differ, the process of the solar dynamo is rather well developed. One just has to look this list on ADS to see how much is being worked on the solar dynamo (and planetary dynamos too, actually, which are not in the list). At to become specific this paper by Weiss and Thompson shows that we are not in the dark even on some of the aspects of the 11 year cycle. You always seem to be rather bold in your statements, which are not really supported by what has been published in the scientific literature.

    I am not sure what I should do with the quote texts that you put into your post. It seems to me more like supposition, that "if the star would have a Maunder minimum then ..." Because, what do they have: observations since the 60, that is 50 years, for the Sun that would be less then 5 cycles. How can you, with statistical significance, say that the star is in a minimum, or that the model describing its variation is off?

    And then the 100s of stars have only been observed for 15 years!

    I think the whole website is rather handwaving and apparently a conference proceedings or something like that. According to ADS this idea was never published in any peer reviewed journal (and the website and pdf on it are from 1998!).
    Hi tusenfem,

    Your paper links did not work for me. I would suggest keeping this thread for solar 24 cycle observations and news releases.

    I will start a new thread to discuss stellar magnetic fields observations and questions.

  12. #222
    After a lull of nearly two weeks, a new sunspot is apparently forming, but belonging to the previous cycle. How long are spots from the earlier cycle supposed to last? Is it always a mixture, or at some point does the old cycle completely stop? Otherwise, at some point in the middle it would be hard to decide whether the spot is (say) cycle 23 or cycle 25.
    As above, so below

  13. #223
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    Quote Originally Posted by Jens View Post
    After a lull of nearly two weeks, a new sunspot is apparently forming, but belonging to the previous cycle. How long are spots from the earlier cycle supposed to last? Is it always a mixture, or at some point does the old cycle completely stop? Otherwise, at some point in the middle it would be hard to decide whether the spot is (say) cycle 23 or cycle 25.
    The sunspots have also been twisting and losing their normal direction. It will be interesting to see how this solar event plays out.

  14. #224
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    The sun was been spotless for 18 days. Long periods of spotless days is unusual anytime and very unusual after the solar cycle minimum. It appears the solar cycle is again having problems starting up.

    http://www.solen.info/solar/


    http://www.landscheidt.info/images/c14nujs1.jpg

    (I have no comment on Geoff Sharp's attempt to link solar angular momentum to the large scale solar changes. Geoff used Solanki's 10,000 year solar activity summary that was reconstructed using the proxy cosmogenic isotopes 10BE and 14C.)

    As noted in this thread, the solar heliosphere doubled in strength during the last 20 years which makes sense as the solar activity in the last 20 years of the 20th century is the highest in 10000 years.

    A rapid change from very high solar activity to extremely low solar activity (Red to blue on Solanki's scale of solar activity) has correlated in the past with a very large increase in volcanic activity, a very large drop in the level of the oceans, and a drop in planetary temperature. (The very large drop in ocean level is not explained by the drop in temperature.) A physical explanation as to why there is this curious correlation of a set of physical changes on the earth when there is an abrupt change in solar activity is not known.

    The last time this occurred (an abrupt change from very high solar activity to a Maunder minimum) was 8200 years ago, however, the magnitude of the change was less 8200 years. This change appears to be the same as the Younger Dryas event 12,700 years ago. There was during the Younger Dryas event the largest change in 14C and 10Be in the last 20,000 years.



    Solankoi's power point presentation provides a good pictorial summary of the solar sunspot mechanism.

    http://www.mps.mpg.de/homes/solanki/...Handout_L2.pdf


    Solankoi's comment concerning the very recent solar change.

    Are we living in special solar times?

    - The Last 50-60 years have seen strongest activity cycles during the last 400 years. Sun has spent only a few % of the last 10000 years at such high activity levels
    - Since 2006 we are in a particularly long and weak minimum, weakest in 80 years minimum, years
    - exceptionally few sunspots
    - open flux is very low
    -irradiance is very low
    -solar wind is exceptionally weak
    -What does the future hold for solar activity? Are we about to leave the Grand Maximum of activity?
    Last edited by William; 2009-Aug-01 at 01:12 PM. Reason: spelling

  15. #225
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    http://users.telenet.be/j.janssens/S.../Spotless.html

    Long, consecutive periods, without sunspots are unusual. (See Solaemon's Spotless Days Page.) The current record for solar cycle 23/24 is 31 days. Tomorrow will be 30 days for this spotless streak.

    http://www.solen.info/solar/

    http://wattsupwiththat.com/2009/08/0...-the-next-day/

  16. #226
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    33 days and the quiet continues. 78 percent of this years days have been spotless.

  17. #227
    And there still doesn't seem to be any sign of activity...

  18. #228
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    Quote Originally Posted by beethovenspiano View Post
    And there still doesn't seem to be any sign of activity...
    I am watching despondently, it's not unusual, rather it was the last 75 years which were unusual.

    Also I would not call the conversion of ~600,000,000 tons of Hydrogen nuclei to helium each second a "lack of activity"
    Last edited by mantiss; 2009-Aug-15 at 07:23 PM. Reason: smart-assedness
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  19. #229
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    This is Livingston and Penn July, 2009 paper concerning the strange decrease in the magnetic field strength of individual sunspots.


    http://www.leif.org/EOS/2009EO300001.pdf

    Are Sunspots Different During This Solar Minimum? By W, Livingston and M. Penn

    …Yet although the Sun’s magnetic polarity has reversed and the new solar cycle has been detected, most of the new cycle’s spots have been tiny “pores” without penumbrae (see Figure 1); in fact, nearly all of these features are seen only on flux magnetograms and are difficult to detect on whitelight images.
    …Four years after the first draft paper, the predicted cycle- independent dearth in sunspot numbers has proven accurate. The vigor of sunspots, in terms of magnetic strength and area, has greatly diminished. Figure 3 shows the decrease in field strength now found with respect to time (1992–2009), which still shows a linear trend independent of the solar cycle.
    What is unusual is the sun is abruptly changing from a Red level solar magnetic activity to blue level solar activity. (See the solar magnetic cycle graph above.) If you look at the solar magnetic cycle graph the last time there was an abrupt change (The other changes were gradual with interim drops.) from Red solar magnetic activity to blue level solar activity was 8200 year BP. However, 8200 years ago the solar magnetic activity was not high as the solar magnetic cycle has been in the last 30 years of the 20th century.
    Last edited by William; 2009-Aug-16 at 12:41 PM. Reason: grammar

  20. #230
    Quote Originally Posted by mantiss View Post
    Also I would not call the conversion of ~600,000,000 tons of Hydrogen nuclei to helium each second a "lack of activity"
    Well that may be technically true. But suppose it started converting 300,000,000 tons of hydrogen nuclie to helium each second? Or even 100,000,000 per second. It would still be a lot of activity. But what we feel on earth might be a lot different.
    As above, so below

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    Every clear day the solar astronomers at the Mount Wilson Observatory 150 foot solar tower do a sunspot drawing. This program has been in operation since 1917. I once asked Dr Steve Padilla about the unusual length of the solar minimum and he did not give an answer. I figure if he did not have an explanation that he refused to make an answer based on speculation.

    For the amateur solar observer/teacher/outreach specialist, the lack of sunspots makes for a rather boring presentation of the Photosphere.

    I am fortunate to own an H-alpha solar telescope.

  22. #232
    We're now up to 37 days without any sunspots. I don't know about the possible effects on the climate, but I find it interesting to consider the possibililty that we could be entering a Maunder Minimum type period. Considering all the satellites that are now monitoring the sun, it would probably give us a lot of interesting data on solar dynamics.
    As above, so below

  23. #233
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    Quote Originally Posted by Jens View Post
    We're now up to 37 days without any sunspots. I don't know about the possible effects on the climate, but I find it interesting to consider the possibililty that we could be entering a Maunder Minimum type period. Considering all the satellites that are now monitoring the sun, it would probably give us a lot of interesting data on solar dynamics.
    It think it's still way too early to call for that, consider the 1900-1902 period and you have a slightly similar lull. The prospect however is intriguing.
    The impossible often has a kind of integrity the merely improbable lacks. -Douglas Adams


  24. #234
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    If we are going into another Maunder Minimum, at least it will shut up the global warming alarmists. Look forward to another mini ice age...

  25. #235
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    Quote Originally Posted by Jens View Post
    Considering all the satellites that are now monitoring the sun, it would probably give us a lot of interesting data on solar dynamics.
    How many spacecraft are monitoring the sun. And can we get real time images from them, other than SOHO, which hasn't been updated in several days?

  26. #236
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    Besides SOHO, there is the TRACE mission. In addition thee Sun is monitored every day at places like the Big Bear Solar Observatory, the Mount Wilson Observatory, Kitt Peak and many other places.

  27. #237
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    Quote Originally Posted by Superluminal View Post
    How many spacecraft are monitoring the sun.
    Besides SOHO and TRACE, let's not forget Hinode, RHESSI, STEREO and the recently decommissioned Ulysses missions. I have probably missed some others, especially balloon-borne and aerial studies.

  28. #238
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    Quote Originally Posted by matthewota View Post
    at least it will shut up the global warming alarmists.
    Was that really necessary?

  29. #239
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    Here is a new probe to add to the list: SDO

    http://www.sciencedaily.com/releases...0811081637.htm.

    Oh, and I dont think a full blown extended minimum (should it come to that) will be pleasant for the inhabitants of our little world given that we have a population that demands large scale agriculture to feed it.

  30. #240
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    Quote Originally Posted by matthewota View Post
    alarmists. Look forward to another mini ice age...
    If you had bothered to read the thread you would know that the opinion of mainstream climate science is that an extended minimum would offset about 7 years of CO2 emissions. So maybe you could refrain from falsely accusing others of being "alarmist" whilst posting up such alarmist hogwash yourself.

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