Cycle 24 Sunspot Observed… At Last!

Thar she blows! Solar Cycle 24 sunspots make their first appearence since January (SOHO MDI image showing Cycle 24 polarity)
Thar she blows! Solar Cycle 24 sunspots make their first appearence since January (SOHO MDI image showing Cycle 24 polarity)

This day has been a long time coming. Ever since the beginning of Solar Cycle 24 back on January 4th 2008, solar physicists have been eagerly awaiting the fireworks to begin… alas, the Sun decided to take a break and stay blank for nine months, keeping any Cycle 24 sunspot activity hidden. That’s not to say there have been no sunspots. Due to a strange quirk in solar activity, the previous cycle took some time to wind down and continued to send groups of spots to the surface, occasionally unleashing some surprise flares and coronal mass ejections (CMEs).

However, it has now been confirmed that the sunspot group seen today by the Solar and Heliospheric Observatory (SOHO) and international amateur astronomers do in fact belong to Cycle 24.

Phew, I was beginning to feel a little chilly

A closeup of the sunspot in question (© Pete Lawrence)
A closeup of the sunspot in question. Observed on September 22nd at Selsey, West Sussex, UK (© Pete Lawrence)

So how do we know these new sunspots have anything to do with the new 11-year solar cycle? Firstly, a quick glance at the SOHO image above tells me that these might be “new” spots as they have been spawned at high latitudes. At the start of a new solar cycle, sunspots tend to appear at high latitudes, and as the (approximate) 11-year cycle progresses, sunspot groups drift toward the equator as solar activity increases. After solar maximum, when you can expect to see a high number of spots, CMEs and flares; the few spots left appear to drift to lower latitudes until they are extinguished at solar minimum.

Like a breath of fresh plasma, there’s an emerging sunspot group on the Sun. This ends a very low period of activity on the solar surface and as it’s a cycle 24 spot group is very exciting indeed. Seeing conditions weren’t brilliant this morning but, to be honest, I don’t care because there’s a sunspot group to look at!!” – Pete Lawrence, Solar Astronomer,

The issue recently is that the solar minimum separating Cycle 23 and 24 appears to have lasted a little longer than expected, prompting some articles to postulate that this could mark the beginning of an extended period of calm. Solar physicists have disputed this, and although NASA made the bold prediction in 2006 that Cycle 23 will be the biggest cycle we’ve ever experienced, many scientists just think this is a glitch and the cycle will continue as normal very soon.

The sunspots as observed at the Isle of Skye, Scotland - Imaged in Hα (© Robert Arnold)
The sunspots as observed at the Isle of Skye, Scotland - Imaged in Hα (© Robert Arnold)

So how else do we know these new spots are from Cycle 24? By taking measurements of the Sun’s magnetic field, SOHO has been able to deduce the direction of the magnetic field appearing from one spot and feeding down into the other spot (sunspots usually appear in pairs, one with a “north” polar field and one with a “south” polar field). During a solar cycle, the global magnetic field of the Sun “flips” (magnetic north becomes magnetic south and vice versa) – this is known as a polarity change, and this flip can be observed in the nature of sunspots. If the leading spot in the sunspot pair becomes “north” after a period when it used to be “south” this means the global field has swapped polarity and a new solar cycle has begun.

This technique was used in January when the first spots of Cycle 24 were discovered, and it was used again to verify the polarity of today’s spots.

This is all great, very nice to see spots from the new cycle again after a nine month break, but does this signify the start of a more active solar disk? Well, that is something we’ll have to wait and find out, the Sun is notoriously difficult to forecast and I doubt it will be revealing its secrets any time soon…

Original source: Space Weather

25 thoughts on “Cycle 24 Sunspot Observed… At Last!”

  1. whew! i wasent looking forward to a another “little ice age”! glad to hear the the sun is finally getting its lazy but in gear!

  2. You said:
    “If the leading spot in the sunspot pair becomes “north” after a period when it used to be “south” this means the global field has swapped polarity and a new solar cycle has begun.”

    However, I believe that is inaccurate…

    My understanding was that the sunspot polarities change at solar MINIMUM, whereas the overall solar magnetic field flips at solar MAXIMUM? Or, am I mistaken on this?

    From wikipedia:

    (Sunspots)

    “From cycle to cycle, the polarities of leading and trailing (with respect to the solar rotation) sunspots change from north/south to south/north and back.”

    “Sunspot activity cycles about every eleven years. The point of highest sunspot activity during this cycle is known as Solar Maximum, and the point of lowest activity is Solar Minimum. At the start of a cycle, sunspots tend to appear in the higher latitudes and then move towards the equator as the cycle approaches maximum …”

    (Solar cycle)

    “The physical basis of the solar cycle was elucidated in the early twentieth century by George Ellery Hale and collaborators, who in 1908 showed that sunspots were strongly magnetized (this was the first detection of magnetic fields outside the Earth), and in 1919 went on to show that the magnetic polarity of sunspot pairs:
    […]

    * reverses itself in both hemispheres from one sunspot cycle to the next.

    […]

    The dipolar component of the solar magnetic field is observed to reverse polarity around the time of solar maximum, and reaches peak strength at the time of solar minimum.”

    If I’ve read it correctly, it says that the sunspots flip polarity at solar minimum reaching peak intensity at solar maximum, whereas the overall dipolar magnetic field of the sun flips at solar maximum and reaches peak intensity at solar minimum. Hmm… ;o] Makes ya’ wonder, don’t it!

    Regards,
    ~Michael Gmirkin

  3. It’s interesting to note that the new Cycle 24 sunspots seem to be greeted with feelings of relief on this site. I assume that’s because these folks associate the absence of sunspots with cold climate conditions. And, after all, who likes chilly weather?

    There certainly seems to be a lot of evidence to support the corellation between sunspot activity and global climate. I never understood why the dear folks at the IPCC deliberately ignore this correlation. Just because we don’t have an iron-clad explanation for it doesn’t mean the correlation isn’t there.

    But, wait a minute, isn’t the world worried to death about global warming? So why is anyone welcoming new sunspots? I would have thought a period of continued global cooling (such as we’ve been seeing during the recent quiet sunspot period)would force the global warming theorists to reconsider the importance of solar activity on climate.

  4. Hi Nick,

    Any relief you sense is purely down to me being bored with a blank Sun. As a solar physicist, I want to see sunspots, coronal loops, CMEs and flares, not a featureless disk. Any comments about me “feeling chilly” at the lack of spots is me trying to be funny.

    There is no way that the Sun can be implicated with global warming, alas, it’s us humans stuffing up the planet, not our star. The reason why the IPCC “deliberately ignore” the Sun-warming link is because there isn’t one. Apparently less than 20% of the global temperature variation can be pinned on solar variability. The other 80% is certainly down to human activity.

    I’ve found that global warming critics are blissfully ignoring the strong CO2 evidence for climate change, citing all sorts of other natural mechanisms. This is what the IPCC base their findings on: Evidence, not ignorance.

    Thank you for sharing your thoughts!

    Hope to see you soon 🙂

    Ian

  5. And yet, there have been prior global warming periods that could not possibly have been man-made… Is it not at least “possible” that there is simply a natural, cyclical variability to weather patterns (whether solar-induced or otherwise)?

    (Captain Cook and Lord Nelson’s logs indicate 1730’s global warming wasn’t man made.)
    http://www.thelondonnews.net/story/390064
    http://www.timesonline.co.uk/tol/news/environment/article4449527.ece

    Just wondering…

    Cheers,
    ~Michael

  6. Ian,

    You must realize how unreasonable it sounds to make a categorical statement like “there is no way the sun can be implicated with global warming.” The sun has been implicated in all past global warmings, so why not this time? How can the close correlation between past variations in solar activity and climate be dismissed? The Maunder Minimum during the “little ice age” and the Dalton Minimum are just two of the more publicized cases. I’ve seen many peer-reviewed technical papers attesting to an observed long-term correlation, with proper account of terrestrial volcanic activity, filtering of sunspot data, and so forth.

    The global warming of the 50 years prior to 1998 happened to coincide with a period of solar activity that was more intense than any known for, what was it, 10,000 years? (I’ll have to look up that paper again.) Then in 2007, when Cycle 24 failed to start on time, global climate started to cool significantly.

    Those sure are a lot of “coincidences.”

    In order to make a statement as unequivocal as yours you must know of a lot of data showing there is no correlation. Every time I try to find something disproving the correlation all I find is evidence supporting it. So I’d appreciate (really) a couple of links to the more convincing arguments supporting your assertion.

  7. It’s iteresting to see Lars graph shows a clear correlation between sun and earth temperature, funny that, apart from the last few years. I’m not against the global warming theory probably true/maybe. But can anyone tell me how come I read an article that seemed credible saying the sun was getting hotter and that polar ice cap’s on certain planets had been melting over the last few years? Was that total crap?

    Any advice or links to credible info would be much appreciated…from an average no solar pleb.

  8. Lars,

    Thanks for the link to the solar irradiance vs. global temperature data. But what those data show is that the previous temperature rise (i.e. prior to the current cooling trend) was not due to changes in that single parameter, solar irradiance. How about X-ray activity, ultraviolet activity, magnetic effects, and (help me out here, solar physicists) other measures of solar activity?

    My most important point is that there is an observed correlation between solar activity and global temperatures. As I mentioned earlier, I haven’t yet seen an irrefutable explanation for that correlation. But our ignorance of the reasons for the correlation don’t justify claiming it doesn’t exist.

  9. When you say “that there is an observed correlation between solar activity and global temperatures”, I’m not sure what you are referring to specifically.

    But this blog post addresses solar magnetism in addition to TSI and also talks about cosmic rays (which some have proposed as a possible mechanism for cloud formation)

  10. Alex says” It’s iteresting to see Lars graph shows a clear correlation between sun and earth temperature, funny that, apart from the last few years.”

    Well, make that the last few decades.

    Years? Decades? Who’s counting?

    Certainly not I.

    And “clear correlation”?

    “Correlation” is in the eye of the beholder, unless you happen to be a statistician, of course.

    Statistics are the ONLY way that you can determine a true — as opposed to apparent — correlation.

    but that does not stop people from trying. There appears to be an entire cottage industry on the web devoted to establish (“by eye”) “deep” correlations between the warming over the past 3 decades and everything but CO2 increases.

  11. Lars,

    With reference to the blog you linked in your 9/30/08 message, there’s a lively discussion (along with handy links to published refutations) of the fallacies embodied in the referenced Lockwood and Frohlich paper at the following site:

    http://www.warwickhughes.com/blog/?p=131

    There’s an especially good refutation by Henrik Svensmark at:

    http://www.spacecenter.dk/publications/scientific-report-series/Scient_No._3.pdf/view

    The Svensmark publication is based on a statistically rigorous analysis. Moreover, the published reviews of the Lockwood and Frohlich paper point out some flawed statistical manipulation in the L&F paper.

    Of particular interest: the Total Solar Irradiance data used in the L&F paper have been “adjusted” to artificially eliminate the upward trend shown by the raw satellite data. There are many people, including some who are closely associated with the satellite instrument that gathered the data in question, who believe that those adjustments were inappropriate.

    There’s also a very fundamental flaw with the L&F approach: The authors imply that there should be an immediate response of global temperature to any change in solar activity. In contrast, it’s well known that the lag time in the earth’s response is at least 10 years due to thermal inertia. That’s why there’s usually no significant response to the 11-year periodic solar cycle. When the lag time is taken into account, the observed global temperature, which stopped rising in about 1998 and in the last couple of years has started to drop, is consistent with the reversal of solar activity in the mid-late 1980s.

    To be fair, I don’t see that lag time in the above Svensmark paper, either. Makes me a little suspicious of the statistical leger-de-main he used. But many of the other points Svensmark makes are valid and worth reading.

  12. Of particular interest: the Total Solar Irradiance data used in the L&F paper have been “adjusted” to artificially eliminate the upward trend shown by the raw satellite data. There are many people, including some who are closely associated with the satellite instrument that gathered the data in question, who believe that those adjustments were inappropriate.

    This presumably refers to the difference between PMOD and ACRIM TSI composites (Neither of which is without “issues”, by the way).

    It turns out that even if you use the ACRIM composite instead of PMOD, the increase in TSI that is suggested by Willson et al (who put together the ACRIM composite) is very small — certainly not sufficient to have caused the global warming we have seen in recent decades (even by Willson’s own admission)

    A comparison of the warming produced assuming each composite is discussed here.

    http://tamino.wordpress.com/2007/07/24/pmod-vs-acrim/

  13. Lars,

    Thanks for the additional link. Lots of good, though-provoking material there, especially the statistical analysis of global temperature trends.

    What confuses me, though, is how starkly the conclusions of that statistical analysis contrast with other more recent information, such as the following item I just culled from the web:

    “Recent studies by the Hadley Climate Research Center (UK), the Japan Meteorological Agency, the National Oceanic and Atmospheric Administration, the University of East Anglia (UK) and the University of Alabama Huntsville show clearly that the rising trend of global average temperature stopped in 2000-2001. Further, NASA data shows that warming in the southern hemisphere has stopped, and that ocean temperatures also have stopped rising.”

    So are the above researchers in need of statistical conseling, using the wrong temperature data, or does tamino need to update his (or her) analysis?

    Another thing that struck me immediately in the referenced link is the Lean (2000) reconstruction of TSI back to the year 1600 or so. That graph shows a pronounced rise in TSI from 1900 to about 1950, with the TSI staying high for the next 50 years or so. The magnitude of the rise between 1900 and 1950 is noticeably greater than the periodic fluctuation during a typical sunspot cycle. It certainly dwarfs the minuscule trend differnce between the ACRIM and PMOD composites. With the TSI staying that high it’s reasonable to see the global temperature continue to rise for a while beyond 1950 as the earth equilibrated to that higher TSI. This is not just a thermal inertia phenomenon, but it also involves climate feedback mechanisms as well.

    And a conspicuous absence from the referenced dialog is any mention of the inverse correlation of cloud cover with solar activity.

  14. …the rising trend of global average temperature stopped in 2000-2001…
    are the above researchers in need of statistical conseling, using the wrong temperature data, or does tamino need to update his (or her) analysis?”

    None of the above. Statistics cautions against making overly confident statements about underlying trends based on short spans of time (like “the rising trend of global average temperature stopped in 2000-2001”) All temperature data is “noisy” and over short periods, the noise can completely obscure the underlying trend.

    From Tamino:

    “Those who point to 10-year “trends,” or 7-year “trends,” to claim that global warming has come to a halt, or even slowed, are fooling themselves. Statistics doesn’t support such a claim, and as
    this example shows
    , it’s really easy for noise to create such a false impression even when we know, without doubt, that the underlying trend hasn’t changed.”

    The relatively small effect of greenhouse gas increases on temperature over a brief time period (eg, less than a decade) is simply obscured by the ‘noise” (weather effects such as El Nino, La Nina) which can exert an effect on temperature that is far greater (by an order of magnitude, in many cases). On the other hand, over the long term (decades), the noise averages out, leaving the underlying upward trend.

  15. Does anyone have the latest status of the Landscheidt Grand Minimum and its impact manifested as this winter’s severe weather anomalies and how this it might affect spring planting and summer crop production?

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