Dartmouth Events

Abstract: The space around the Earth is filled with fast moving particles trapped in two "belts" by our magnetic field. The belts were named the "Van Allen radiation belts" in 1958 in honour of their discoverer, James Van Allen. Earth-orbiting satellites can be damaged or even lost due to increased high-energy electron fluxes in the Earth's radiation belts. Electron fluxes are highly variable, with fluxes changing by many orders of magnitudes on time-scales of hours to days, due to competing acceleration and loss processes.

There is increasing international interest in losses from the Van Allen belts. Some of this comes from the community focused on radiation belt physics, trying to understand the fundamental processes occurring in the belts. However there are also complementary questions in ionospheric, atmospheric and climate science as to the importance of energetic electron loss, termed precipitation, into the polar atmosphere. There is a growing scientific realisation that atmospheric changes due to these electrons may be "significant" - leading to important changes in the chemical makeup and dynamics of the upper atmosphere, as well as suggestive studies showing links to polar surface temperatures, i.e. polar climate. In this talk I will give an overview on this research area, and focus particularly on our efforts to quantify the time-varying energetic electron precipitation fluxes.

Professor Craig Rodger is visiting Dartmouth through the Matariki Network of Universities, which Dartmouth and Otago are both members of. He is the leader of the Space Physics and Atmospheric Radio research group in the Physics Department, University of Otago, Dunedin, New Zealand. Craig operates ground-based detectors in Antarctica, New Zealand and the Arctic, and is the co-PI of the AARDDVARK network.