Radiation Belt Modelling
The vast expanse of space is not an empty vacuum but is instead filled with electrically charged particles that create a fourth state of matter known as plasma. Generated at incredibly high temperatures, plasma is predominantly produced by stars, including our Sun, which constantly emit a solar wind consisting of plasma that travels into interstellar space at hundreds of kilometers per second. Though less familiar than solids, liquids, and gases, plasma makes up more than 99% of the universe's material. Unlike the other states of matter, plasma dynamics are governed by electromagnetic forces due to the presence of charged particles.
The Earth's magnetic field, resembling a bar magnet, forms a protective barrier that shields us from the majority of the potentially hazardous solar wind plasma. This magnetic field interacts with the solar wind through various complex and dynamic processes, including the global-scale phenomenon known as the 'Dungey Cycle'. This cycle allows plasma from the solar wind to enter Earth's magnetic field on the nightside, leading to plasma enveloping the Earth at various altitudes. The Earth's magnetic field and surrounding plasma together form the magnetosphere, which hosts numerous highly energetic dynamics driven by the solar wind.
Instabilities in the plasma can generate electromagnetic waves that propagate throughout the magnetosphere and interact with other charged particles, accelerating them to near-light speeds through resonant interactions. These regions, known as radiation belts, pose significant risks to the hundreds of operational satellites that traverse this hazardous environment. These satellites, crucial for navigation, communication, defense, and Earth observation, are vulnerable to damage or loss due to highly energetic particles.
Space weather, including the risks associated with the radiation belts, is recognized as a significant concern in the UK Cabinet Office National Risk Register of Civil Emergencies. Recent satellite observations have shown that electromagnetic waves can possess higher amplitudes and energize plasma particles more rapidly than previously thought, yet no existing space weather forecasting models account for these effects. This Fellowship's ultimate objective is to enhance the forecasting accuracy of the British Antarctic Survey's world-leading model, licensed to the UK Met Office, by understanding and incorporating the impact of high amplitude waves on particle dynamics—an increasingly critical endeavor as society becomes more reliant on satellite technologies.