Auroral Currents

This guided inquiry activity gives students the opportunity to practice and extend their knowledge of magnetic fields produced by current-carrying wires. They examine perturbations in the Earth’s magnetic field as measured by the International Real-time Magnetic Observatory Network (using data publicly available at www.intermagnet.org) to infer the direction and strength of currents running through the ionosphere. The aurora is created by electric currents from space that flow along the magnetic field into and out of the ionosphere. These charged particles move horizontally through currents called the auroral electrojets. This activity is appropriate for university introductory physics and astronomy courses.

Use the selected response questions to probe student thinking about the magnetic fields produced by line currents. The entire sequence of questions provided here is intended to guide students to use their knowledge about long current-carrying wires to model the magnetic effects of currents in the Earth’s ionosphere associated with aurorae. This resource is designed to be used either as homework or in small discussions with methods such as Peer Instruction, Teaching with Clickers, or CAE Think-Pair-Share. Watch the pre-lecture video to learn more about implementing the activity.