Plasma and Space Physics

The Plasma and Space Physics at Dartmouth consists of experimental and theoretical research groups in the Department of Physics and Astronomy and at the Thayer School of Engineering, which study the near Earth space environment, including phenomena such as the Northern (and Southern) Lights and the Van Allen radiation belts. Our dynamic variable star, the Sun, with an 11-year cycle of sunspot activity, drives phenomena in the Earth's atmosphere, ionosphere and magnetosphere, the cavity which the Earth's magnetic field carves out in the Sun's expanding atmosphere or solar wind. The experimental groups in Physics and Astronomy (LaBelle, Lynch, Millan) measure waves, charged particles and x-rays using ground-based, rocket and balloon platforms, as well as observational databases from spacecraft.  Theoretical and computational modeling of magnetospheric processes and "space weather" is carried out by Lyon, Denton, Müller, Liu and students. Fundamental plasma physics processes creating disruptions in fusion plasmas also cause solar flares and create night-time "explosions" of aurora across the polar skies. The phenomenon of "magnetic reconnection" which converts magnetic field energy into particle kinetic energy in broad settings of space, planetary and astrophysical systems is the focus of Liu's group.

Yi-Hsin Liu's research focuses on the fundamental physics of magnetic reconnection with a broad application to ionospheric, magnetospheric, solar and astrophysical plasmas. Magnetic reconnection is a nonlinear, dynamical process that involves electromagnetism, geometry, and complex particle kinetics in a multi-dimensional, multiscale system, where a topologically singular point in the microscale leads to tremendous energy release in the macroscale. He is an active member of the Theory & Modeling team of NASA's ongoing Magnetospheric Multiscale (MMS) Mission, which is designed to revolutionize our understanding of magnetic reconnection in nature. In addition to reconnection, Yi-Hsin also studied collisionless shocks, turbulence, and particle acceleration. More information can be found on his research website.

Barrett Rogers's research applies to both fusion science and space physics, including physics of magnetic reconnection, particle acceleration, global magnetosphere simulations, turbulent cascades, and fluid and kinetic simulations of plasma instabilities.

Richard Denton's research is predominantly on techniques to infer the spatial structure of the magnetic field in the vicinity of spacecraft using their measurements at the locations of the spacecraft,  modeling of magnetospheric electron and mass density, and  studies of ultralow frequency waves,  in particular, electromagnetic ion cyclotron waves. Richard currently works out of his home in Florida, but collaborates with other researchers at Dartmouth.

John Lyon developed the Lyon-Fedder-Mobarry 3D global MHD code for simulation interaction of the Earth's ionosphere and magnetosphere with solar wind plasma. It is now available for runs on demand at NASA's Community Coordinated Modeling Center and is used by researchers worldwide. It is currently being replaced at CCMC by the Gamera (Grid Agnostic MHD for Extended Applications) model which he helped develop and which modernizes the computational core of the LFM. He is currently working on Hall MHD and anisotropic MHD for the Earth and the outer planets and satellites. 

Hans Müller carries out simulations of the global heliosphere, which is where the solar wind interacts with the partially ionized local interstellar medium. The accurate calculation of the neutral atom - plasma interaction and its consequences for the heliosphere and for spacecraft observations is a particular focus of his studies. He applies this expertise also to similar astrospheres around other stars, and to modeling of the signature of evaporating neutral exospheres of close-in exoplanets as they interact with stellar winds.

James LaBelle's research focuses on measurements of plasma waves using NASA sounding rockets and ground-based radio techniques to remotely sense ionospheric plasma processes. The ground-based research is deployed at remote locations including Antarctica, Greenland, Alaska and Northern Canada. LaBelle has active collaborations with groups in North America and Europe.

Kristina Lynch's research focuses on the plasma physics of the Northern Lights. She uses the lower ionosphere as a laboratory for studying interactions between plasmas and probes through sheaths, and between the magnetosphere and the ionosphere through aurora. In the laboratory, her students can generate an ionospheric-like plasma in a large vacuum chamber called "the Elephant".  Recent efforts include collaborations with the GEMINI ionospheric modeling development team, for modeling the auroral ionosphere and interpreting heterogeneous data;  and collaborations with a consortium including Calgary and University of Alaska Fairbanks and SRI, to develop heterogeneous observational databases of the auroral environment.  The NASA-funded GNEISS auroral sounding rocket(s) (a pair) will be developed (launch in winter 2026 from Poker Flat Alaska) to study auroral system science.

Robyn Millan's research focuses on energetic particles in astrophysical settings. Millan's current experiment (BARREL) will study the Earth's radiation belts using a flotilla of balloons launched from Antarctica.

Simon Shepherd's research involves remote sensing various ionospheric phenomena, radiowave propagation and coupling to the magnetosphere and thermosphere systems, primarily using the Super Dual Auroral Radar Network (SuperDARN). He is principal investigator of four SuperDARN radars located in Oregon and Iceland.