Space weather can cause electric currents to flow through the ground at the Earth’s surface. These currents correspond closely to the rate of change of the magnetic field, following Faraday’s law of induction. The scientific community regularly uses two different methods to calculate the rate of change of the magnetic field for this purpose. We show that there is a large difference between the two methods, and highlight certain situations where this difference is potentially significant.

Written for the centennial anniversary of the International Union of Geodesy and Geophysics (IUGG), this paper documents the activities of the Union at the beginning of the 21st century. IUGG added an eighth association on cryospheric sciences, introduced new categories of affiliate and honorary memberships, new grants, science education, and recognition programs, and formed new commissions on climatic and environmental change, data and information, planetary sciences, and history.

As computing and geophysical sensor components have become increasingly affordable over the past decade, it is now possible to build a cost-effective system for monitoring the Earth's natural magnetic field variations, in particular for space weather events, e.g. aurorae. Sensors available to the general public are ~ 100 times less sensitive than scientific instruments but only 1/100th of the price. We demonstrate a system that allows schools to contribute to a genuine scientific sensor network.

This paper describes the study of the effects of solar wind and solar storms on the national electrical power transmission grid in Austria. These storms result in currents in the ground that can cause damage to power grids, particularly those at high latitudes. Results show that very strong solar storms could result in problems in Austria as well, and this information is important to the grid operators to properly implement mitigation strategies in the future.