Earth's magnetic field is ringing like a bell – go to http://spaceweather.com 22nd February … a stream of solar wind is passing just south of the Earth making a grazing contact with the magnetosphere. This is causing the unusual swinging back and forth that is like a ringing bell. The low frequency oscillation went on for over an hour. In spite of the glancing blow it did cause auroral lights over the Arctic – see image below taken in Lapland.
