Geomagnetic storms

A paper published by the Annales Geophyscae 27 (2009) (see www.ann-geophys.net/27/185/2009 or www.ann-geophys.net/27/185/2009/angeo-27-185-2009.pdf ) is about the connections between sun spots and geomagnetic storms. At www.sciencemag.org/content/108/2805/354.extract there is a short piece on the Great Sun Spot of 1947 – accompanied by bursts of solar noise – yes, noise. An hour long burst of solar noise occurred two days running with intermittent periods on both days. The story appeared in Science of 1st October 1948 volume 108 no 2805 pp 354-5 DOI: 10.1126/science.108.2805.354