Backward Sunspot Could Signal New Cycle

Links to the story “Backward Sunspot” have appeared in quite a few of the maililng lists I subscribe to.  Aside from the good news that the backward sunspot  may signal the start of a new sunspot cycle, the article is interesting reading.

Here’s something I just learned about sunspots:

“Backward” means magnetically backward. [David] Hathaway, [a solar physicist at the Marshall Space Flight in Huntsville, Alabama] explains:

Sunspots are planet-sized magnets created by the sun’s inner magnetic dynamo. Like all magnets in the Universe, sunspots have north (N) and south (S) magnetic poles. The sunspot of July 31st popped up at solar longitude 65 degrees W, latitude 13 degrees S. Sunspots in that area are normally oriented N-S. The newcomer, however, was S-N, opposite the norm.

Looks like the fun is about to begin.


  1. That is one observation. Another quite opposite (which seems to coincide with what many experts have been saying for the past year or so), came in the ARRL propagation report today. The speculation is fun while we await the event getting here though………..

    SB PROP @ ARL $ARLP037
    ARLP037 Propagation de K7RA

    ZCZC AP37
    QST de W1AW
    Propagation Forecast Bulletin 37 ARLP037
    From Tad Cook, K7RA
    Seattle, WA September 8, 2006
    To all radio amateurs

    ARLP037 Propagation de K7RA

    Average daily sunspot numbers were down only slightly this week,
    from 27 to 25.3. There were two days this week when the sunspot
    number was 0, and we should see more zero sunspot days than we’re
    currently experiencing as we move closer to the bottom of the
    sunspot cycle.

    The last solar minimum was centered near October 1996, according to
    the NOAA SEC graphs on page 11 of their weekly report at,

    If you look at the average sunspot numbers reported in our
    propagation forecast bulletins from September 13, 1996 to October
    25, 1996 (located on the web at, you’ll see week after
    week of no sunspots.

    Currently we’re observing average daily sunspot numbers near 25 for
    this week, 27 for last, 22 the previous week, and 34 prior to that.
    According to weekly NOAA SEC sunspot predictions, on the web at,, these averages are
    above the high end for this month and last, and the minimum is about
    six months away. But look back on that 1996 index mentioned above,
    at the numbers reported in this bulletin six months prior to the
    last minimum. Weekly averages reported here during April 1996 were
    near 12, 2, 7, and 20. Does this suggest the sunspot minimum is
    further away, rather than next spring?

    Also note on page 11 in that first reference in the second
    paragraph, the spacing of the sunspot cycle minimums. From the end
    of cycles 17 to 19 they are a little over ten years apart, from 1944
    to 1954 and 1964. Then it jumps less than 12 years (from October
    1964 to June 1976), and it goes back to a little over ten years from
    1976 to 1986, and then 1996. Next spring will be a bit less than 11
    years since the last minimum.

    Right now is a fairly good time for long-distance HF communications,
    because the geomagnetic field is mostly stable, sunspots haven’t
    disappeared, and we are close to the Autumnal Equinox. Running
    intercontinental paths with ACE-HF propagation software shows very
    little in the way of openings on the upper bands above 20 meters,
    with the best bets on 40, 30 and 20 meters.

    If you would like to make a comment or have a tip for our readers,
    email the author at,

    For more information concerning radio propagation, see the ARRL
    Technical Information Service at, For a detailed
    explanation of the numbers used in this bulletin, see An archive of past
    propagation bulletins is at, .

    Sunspot numbers for August 31 through September 6 were 39, 32, 27,
    0, 0, 26 and 53 with a mean of 25.3. 10.7 cm flux was 83.2, 76.9,
    75.6, 76.5, 79, 80.4, and 84, with a mean of 79.4. Estimated
    planetary A indices were 8, 13, 7, 6, 23, 8 and 7 with a mean of
    10.3. Estimated mid-latitude A indices were 6, 8, 6, 6, 15, 7 and 6,
    with a mean of 7.7.

    Your mileage may vary.


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