Solar Science

A blog of solar physics

Previous predictions of solar cycle 24

with 6 comments

From NASA website:

Solar cycle 24, due to peak in 2010 or 2011 “looks like its going to be one of the most intense cycles since record-keeping began almost 400 years ago,” says solar physicist David Hathaway of the Marshall Space Flight Center. He and colleague Robert Wilson presented this conclusion last week at the American Geophysical Union meeting in San Francisco.

Their forecast is based on historical records of geomagnetic storms.

Hathaway explains: “When a gust of solar wind hits Earth’s magnetic field, the impact causes the magnetic field to shake. If it shakes hard enough, we call it a geomagnetic storm.” In the extreme, these storms cause power outages and make compass needles swing in the wrong direction. Auroras are a beautiful side-effect.

Hathaway and Wilson looked at records of geomagnetic activity stretching back almost 150 years and noticed something useful:. “The amount of geomagnetic activity now tells us what the solar cycle is going to be like 6 to 8 years in the future,” says Hathaway. A picture is worth a thousand words:

Hathaway's comparison of solar and geomagnetic fields

Hathaway's comparison of solar and geomagnetic fields

Above: Peaks in geomagnetic activity (red) foretell solar maxima (black) more than six years in advance. [More]

In the plot, above, black curves are solar cycles; the amplitude is the sunspot number. Red curves are geomagnetic indices, specifically the Inter-hour Variability Index or IHV. “These indices are derived from magnetometer data recorded at two points on opposite sides of Earth: one in England and another in Australia. IHV data have been taken every day since 1868,” says Hathaway.

Cross correlating sunspot number vs. IHV, they found that the IHV predicts the amplitude of the solar cycle 6-plus years in advance with a 94% correlation coefficient.

“We don’t know why this works,” says Hathaway. The underlying physics is a mystery. “But it does work.”

And here’s the prediction for Solar Cycle 24 based on this “mystery”:

Hathaway's 2006 prediction of SC24

Hathaway's 2006 prediction of SC24

Never mind that this thing looks a lot like numerology – if its from NASA and has a nice graph it must be worth something

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Written by John A

March 21, 2007 at 9:50 pm

6 Responses

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  1. […] Yes. The same organization and the same scientist that predicted a strong solar cycle 24 according to a prediction based on changes in the Earth’s magnetic field, predicts a weak solar cycle 25 based on observations of the Sun (for a change) May 10, 2006: The Sun’s Great Conveyor Belt has slowed to a record-low crawl, according to research by NASA solar physicist David Hathaway. “It’s off the bottom of the charts,” he says. “This has important repercussions for future solar activity.” […]

  2. When a “sudden gust of solar wind” hits the earth, doesn’t it bring more IR radiation (heat) with it? Since solar cycle 24 is supposed to be intense and peak around 2011, doesn’t that mean that the Earth will warm even more than now?

    This non-academic wants to know.

    Mike Neibel

    May 19, 2007 at 4:16 pm

  3. […] brings us to an interesting situation. After what one astrophysicist communicated to me seemed a lot like numerology in a prediction by NASA, and after statements about the strength of Solar Cycle 24 by the same group, we now have a […]

  4. Mike,

    My understanding is that yes, a strong solar wind warms the Earth, but the major factor would appear to be the strengthening of the solar magnetic field, which deflects the cosmic rays that appear to have a measureable effect on the formation of clouds, especially in the lower atmosphere.

    Less cloudiness -> lower albedo -> warming.

    So its a double whammy if you like.

    John A

    May 20, 2007 at 12:40 pm

  5. It’s more subtle than that. It’s the collective effect over many cycles, the peak freqency, that matters. Visit the Danish National Space Center web site. There you will see evidence that there is a strong correlation between solar activity and global climate. High solar activity shields earth from cosmic radiation; a quiet sun does not shield earth. Cosmic radiation is very efficient at producing low level cloud. The correlation between sunspot peak frequency and warming and cooling is 95% (Friis-Christensen, and Lassen, 1991; Science). Corrrelation is not causation; that pattern was destroyed by the Pinatubo eruption, but the Danes have actual experimental support (Svensmark, et al, 2006) for the solar hypothesis of climate change. Read “The Chilling Stars” for a chilling story.

    Dr. Francis T. Manns

    December 2, 2007 at 11:17 am

  6. I would think one of these scenarios more likely:
    1) Earth’s geomagnetic activity fluctuates enough to allow correlations to be found between the two graphs, with these two observations: 1A) data shopping; choosing geomagnetic peaks which roughly match the solar activity peaks using the disired displacement. 1B) ignoring troughs in the geomagnetic graph, which line up better with the solar activity peaks. After all the sun’s not that far away…why should years for Old Sol to affect the Earth’s…oh, I forgot, the influence is Earth – Sol…

    2) Assuming the influence might possibly be big Sol influencing smaller Earth, perhaps the arrows on the graph would be better placed with the first arrow’s tail at the peak of Solar Cycle 11 and the arrow’s head at Geomagnetic peak at ~1870, and continuing demonstrating how each Solar Peak is followed by a Geomagnetic Peak.


    December 3, 2007 at 6:48 pm

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