Previous predictions of solar cycle 24
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:
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”:
Never mind that this thing looks a lot like numerology – if its from NASA and has a nice graph it must be worth something