Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


What is heliophysics?  An attempt share space plasma physics with the larger science community

Peter Delamere
Physics Dept./GI UAF



The American Physical Society/Division of Plasma Physics organizes a series of DOE-funded lectures to share recent advances in plasma physics with the larger scientific community (DLPP).   I volunteered to serve a two-year appointment to this program to promote heliophysics.  My challenge is to distill space plasma physics for a general (likely undergraduate/graduate physics) audience.  Your challenge is to provide constructive feedback before this presentation “hits the road”. It is also possible that new insights might be found on the topics highlighted in the DLPP abstract below!

The heliosphere is a bubble of magnetic-field pressure and plasma-particle pressure immersed in the vacuum of interstellar space. The heliosphere is comprised of the tightly spiraled, outward drifting, solar magnetic field and an initially supersonic, cross-field, plasma outflow (called the solar wind) from the Sun. Dotting the heliospheric volume are pockets (plasma cavities, or magnetospheres), formed by the interaction between the solar wind with planetary magnetic fields, and obstacles (plasma clouds and/or planetary atmospheres), formed by mass-loading the solar wind passing by with ionized atmosphere. A cornerstone of research in the field of space plasma physics is understanding the deflection of the solar wind by an isolated solar system object (e.g., planet, moon, comet) and the object’s complicated interaction with its local plasma environment. Common features of these interactions include an upstream (sunward) shock/wave front that slows and heats the solar wind plasma over a relatively short distance and a downstream (anti-sunward) comet-like tail that flaps and snaps dynamically over a relatively long distance of hundreds of object diameters. Forecasting the electromagnetic “space weather” events at Earth as well as interpreting what the aurorae tell us about each planet’s magnetic cavity relies on the fundamental plasma processes that mediate these interactions. We will discuss plasma waves generated by solar wind interactions from Mercury to Pluto. Specific topics include magnetic-field reconnection and the generation of Kelvin-Helmholtz waves at the boundaries of the solar system objects.


Friday, 28 April 2017

Globe Room, Elvey Building

3:45 PM