PREEVENTS Track 2: Integrated Modeling of Extreme Space Weather Events from Electron to Global Scales

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Space weather results from solar activity that can affect the space environment of Earth, damage our technological systems, and expose pilots and astronauts to harmful radiation. Extreme space weather events are caused by sudden reconfigurations of the magnetosphere, the magnetic field surrounding and protecting Earth, caused by magnetic reconnection, which can be thought of as a magnetic explosion. Reconnection happens on scales much smaller than the magnetosphere. The project will predict the effects of extreme space weather events with a sophisticated computer model. Using innovative algorithms and state-of-the-art models, the project will realize the first-ever self-consistent global simulations of extreme space weather events that capture the physics of reconnection. Extreme space weather events could knock out the power grid on Earth with a recovery time of months and the large-scale loss of electricity for an extended time and could collapse our technological infrastructure. The results of this project will allow quantitative assessment of the various impacts, which is needed for prevention plans and engineering solutions. This project supports the training of multiple graduate students. Current magnetosphere models, including the Michigan Geospace model being transitioned to operation at the Space Weather Modeling Center of NOAA, employ a magnetohydrodynamic (MHD) approximation that cannot account for the kinetic processes responsible for magnetic reconnection. Only first-principles, fully kinetic codes can reliably model reconnection, but global kinetic simulations are not affordable on current or even near-future computers. The recently developed MHD with embedded particle-in-cell (MHD-EPIC) algorithm offers a unique solution. The MHD code provides the global solution in the full computational domain, while the fully kinetic EPIC code models the parts of the domain where reconnection occurs. MHD-EPIC is much more efficient than a global kinetic model and this technique has been successfully validated for several space physics systems, including the magnetospheres of Ganymede, Mercury, Mars and Earth. The MHD-EPIC model will be employed to study extreme space weather events. First the model will be validated against observations for well-observed strong magnetic storms. Then the validated model will be used to simulate what would have happened if the July 2012 Carrington-scale solar eruption had not missed Earth. Idealized and scaled-up real events will be modeled to investigate various scenarios: extreme solar wind ram pressure, magnetic field, duration, and variability. For each run the local surface magnetic field variations will be calculated and serve as input for physics-based models of power grids.