Space weather refers to the conditions in space, in the upper atmosphere, and on ground created by the plasma and magnetic fields emanated from the Sun interacting with the Earth’s internal geomagnetic field. The magnetosphere, the Earth’s magnetic environment, is shaped through this interaction and hosts multiple plasma populations that vary in a multitude of temporal and spatial scales. Space weather can have adverse effects on technology or humans in space and on ground. Understanding space weather variability, and when and where the most hazardous disturbances occur, is at the heart of our research.
The space environment can be studied by measurements made on ground or in space as well as by numerical models and simulations. Our group employs all these methodologies:
- Ground-based measurements provide a view of the ionospheric state. Ground-based magnetic recordings are used to infer the electric currents and magnetic field variations in the auroral region upper atmosphere and in the near-Earth space where e.g. the GPS, communication and weather satellites reside. Auroral imagers in Canada and Scandinavia record light created by currents flowing from space to the atmosphere, and tell us about the coupling between the two. Ionospheric radars measure upper atmosphere plasma flows and electric fields, providing information about its electrodynamics.
- In-situ satellite measurements provide point measurements of the electromagnetic fields and waves, ions and electrons. NASA’s Heliophysics System Observatory provides a rich fleet of spacecraft that are used to observe the system dynamics in the solar wind and in the magnetosphere. However, the still sparse coverage of measurements from the vast region of space often makes interpretation of the signals challenging – this is where models come to help.
- Numerical simulations of the solar wind – magnetosphere coupling provide a global view of the geospace dynamics. Data – model comparisons can tell us about the accuracy of the models as well as the global processes that give rise to the local signals measured by the spacecraft.
