Supermag: the Global Ground Magnetometer Initiative

For decades ground based magnetometers have proven to be the workhorse of magnetosphere-ionosphere physics and their importance is indisputable. The data set provided by the ground magnetometer community is truly unique since it provide continuous and nearly global measurement of a fundamental parameter - the ground level magnetic field perturbations. The SuperMAG initiative (Gjerloev, 2009) provide a fully operational solution to these complications. This is a worldwide collaboration of organizations and national agencies that currently operate more than 300 ground based magnetometers. SuperMAG provides easy access to validated ground magnetic field perturbations in the same coordinate system, identical time resolution and with a common baseline removal approach. The purpose of SuperMAG it to help scientists, teachers, students and the general public have easy access to measurements of the Earth's magnetic field. In addition to a presentation of the initiative itself we discuss results from published studies enabled by SuperMAG.