Robert Weigel | Department of Computational and Data Sciences, Department of Physics & Astronomy, George Mason University

Thursday March 8, 4:30 PM | Research 1 Room 301

Seasonal variations in geomagnetic activity

There are two contributors to the magnetic filed measured at Earth's surface. The first is the core dynamo, which causes a dipolar magnetic field that is referred to as the main field.  The second is external (magnetospheric) current systems that are a result of the interaction and distortion of the main field by the solar wind.  The geomagnetic perturbations caused by these current systems are known as geomagnetic activity.  In this seminar I will review some of the processes that generate these current systems and then describe a long-standing question about geomagnetic activity: why does it peak in spring and fall?  Previous answers to this question only explain 0-33% of the observed variation.  I will present a recently developed model that explains 50-80% of the observed variation.

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