Statistics of Magnetospheric Sawtooth Oscillations

Magnetospheric sawtooth events (STE) are periodic oscillations in Earth’s magnetic field and energetic particle fluxes, typically occurring during geomagnetic storms. While previous studies have helped to provide information about the characteristics of STEs and the conditions that lead to the onset of these events, very little research has been done in the past 10 years documenting STEs, and analyzing the inner magnetosphere magnetic configuration during sawtooth events. This information can help understand how storms and substorms affect ionosphere-thermosphere convection, and how low-latitude ionospheric disturbances are generated during substorms. This project uses observations from magnetospheric missions and ground-based magnetometer networks to study the sawtooth event processes. Using magnetic field measurements GOES and the auroral electrojet indices, we are able to identify and catalog sawtooth events. We present our methods for identifying sawtooth events and preliminary statistics of the event characteristics. Then using magnetic field measurements from the THEMIS, RBSP, and MMS missions, we will study the evolution of the ring current and its latitudinal and longitudinal variations during STEs. We will also assess the abilities of the empirical Tsyganenko field models to reproduce the magnetospheric conditions during sawtooth events.