Sunspots at a 50-year low
October 2, 2008
Apparently, the last year that had a higher count of days in which no sunspot activity was observed on the face of the Sun was way back in 1954
. And if less than 50 days between now and the end of the year demonstrate any indication of sunspot activity, 2008 will replace ‘54 as the third-place champion for spotlessness in the last century.
From NASA yesterday:
Sept. 30, 2008: Astronomers who count sunspots have announced that 2008 is now the “blankest year” of the Space Age.
As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.
“Sunspot counts are at a 50-year low,” says solar physicist David Hathaway of the NASA Marshall Space Flight Center. “We’re experiencing a deep minimum of the solar cycle.”
And why the blankety-blank does this matter? From Planet Gore in May:
Sunspots are magnetic storms on the sun’s surface that are used as a proxy measure for the Sun’s interplanetary magnetic field. As Henrik Svensmark and Fred Singer argue, the Sun’s magnetic field effects cloud formation in the Earth’s upper atmosphere. The more magnetically active the Sun is, the fewer cosmic rays reach our upper atmosphere. When cosmic rays do reach the Earth, they react with atmospheric gases to free nuclei that help seed cloud formation, cooling the Earth’s surface.
No sunspots = more clouds = lower temperatures.
Coincidentally, the Earth’s average temperature has been dropping since at least January of this year.
Or perhaps…not so coincidentally.
Update: Welcome, Steynians!
Which leaves unanswered, I suppose, the question of why warming trends analogous to trends observed on Earth have been observed on other planets in the Solar System, most notably Mars. It also leaves unanswered, one must note, the question of why most of the observed global average temperature increases have been undone in recent months, corresponding to the observation that the Sun, having finished one sunspot cycle, has not begun another one (contrary to expectations).
The article’s headline is a bit misleading, methinks. The specific solar radiation under discussion is what are called cosmic rays, the really intense radiation that the Sun gives off. Most of that stuff gets blocked by the Earth’s magnetic field anyhow — one of those beautifully-designed things, you know? Of course, cosmic rays are not the only sort of radiation emitted by the Sun, and radiation in other parts of the spectrum can penetrate the magnetic field (ultraviolet radiation would be an easy example to point to here).
The fact is, we can be fairly certain that what solar radiation does penetrate the magnetic field must be responsible for warming the Earth, because we are fairly certain that were the Sun to suddenly stop emitting said radiation, the Earth would become a frozen wasteland. Whatever solar radiation gets through the magnetic field is responsible, in large measure, for the fact that the temperature in most places on the Earth’s surface is in a range that humans find liveable. It still seems reasonable, even in light of findings which suggest that Henrik Svensmark may have been wrong in his theories about cosmic rays, that variations in the Sun’s output in other spectra still do produce changes in the Earth’s climate and average temperature.
Especially, I note again, since similar trends have been observed on other orbital bodies in the Solar System which, last time I checked, were not home to advanced, industrialized societies.
