Comment on “The predictability of the magnetosphere and space weather”



Although the emphasis of the Eos article by Li et al. (16 September 2003) describing the predictability of the magnetosphere and space weather was not history, I would like to point out two historical errors that should be of interest to the readers of Eos. The first is the following assertion: “That the Sun might influence the Earth's magnetic field… was first realized in 1859, when the largest magnetic storm ever recorded occurred 17 hours after a white light flare on the Sun.” Seven years earlier, both Sabine [1852] and Wolf [1857] independently found that geomagnetic activity had the same 11-year periodicity as the number of sunspots. Sabine concluded “…it is quite conceivable that affections of the gaseous envelope of the sun…may give rise to sensible magnetical effects at the surface of our planet…” [Sabine,1852].