Date: Thursday, August 16, 2007
Time: 10:30am
Location: NIA, Room 137
Additional Information: Presentation (.pdf)

The Evolution of High-Latitude Potential Models and Applications
Daniel R. Weimer, Solana Scientific, Inc.

An empirical model of the high-latitude, ionospheric electric potential, derived from satellite electric field measurements, provides maps of the electric potential as a function of the Interplanetary Magnetic Field (IMF) and solar wind conditions. A twin model of "magnetic Euler potential," derived from satellite magnetometer measurements, also maps the field-aligned currents (FAC) as a function of the IMF. This presentation will review the evolution of these models over a period of time. Starting with the basic, canonical maps of the electric potential for specific IMF values in the mid-90's, there has been a progressive development in capabilities, culminating in the latest, non-linear models for arbitrary IMF conditions. The technique used to map the FAC, invented by the author, was found to have uses not originally envisioned. In combination with the electric potential model, the magnetic potentials can be used to calculate ionospheric Joule heating, as well as geomagnetic perturbations on the ground. When used with the real-time IMF measurements from the ACE satellite, these models can provide a predictive capability of "space weather" conditions.