Craig Kletzing's

    Research Interests

My research focuses on making in situ measurements of the plasma environment of the Earth's magnetosphere. Within the magnetosphere, my primary research interest is auroral physics and magnetosphere-ionsphere coupling processes. Much of my work has concentrated on measurements of the electrons and ions in this region. These measurements are made both by satellites and small, sub-orbital rockets known as sounding rockets. Several of these sounding rocket flights have been over active aurora - a phenomena which is one of my strongest research interests. I am quite interested in understanding interactions between waves and particles to understand how energy exchanged between electric and magnetic fields and the kinetic energy of particles. To further this understanding I want to develop new techniques for measuring wave-particle correlations. These interactions can occur an MHz frequencies so this is a challenging experimental problem, but one for which there are several possiblilities for improving on current instrumentation. We had a rocket flight that will fly in the Winter of 2002 that investigated these wave-particle correlations and we are currently analyzing the data from the flight. We flew another rocket in the Winter of 2003 to investigate particles and waves above the Langmuir frequency. We will fly another wave-particle correlator on the CHARM rocket in the Winter of 2007.

Extending outward from the auroral zone, we have electron and ion data from the Hydra instrument on the Polar satellite which was just launched in February of 1996. By analyzing the particle data from these missions (along with electric and magnetic field data taken at the same time) we can infer characteristics of the processes that create the aurora. I have been examining particle data for times when the Polar satellite is at high altitude in the northern auroral zone. The satellite is at sufficiently high altitude that one can be certain that it is above the region in which auroral electrons are accelerated. This allows us to probe the source populations for the aurora with good resolution. Currently, I am working on correlations studies to determine which (if any) solar wind parameters are correlated with the characteristic energy and density of the auroral source population.

I am also involved in an exciting new technique to measure electric fields in space using electron beams. An experiment using this technique was flown on a German-Swedish satellite called Freja which was launched in October of 1992 from China. The focus of this mission was also auroral physics and we were able to demonstrate that this new technique works quite well. In particular the technique allows a full vector determination of the electic field perpendicular to the background magnetic field. This is not always possible with other techniques and thus this new method provides a complement to existing techniques. Now that the method is validated we are concentrating our efforts on using this data to better understand auroral electrodynamics.

Another implementation of this technique that will flown on the Equator-S satellite to be flown in the next year. Originally this experiment was to be flown on the four Cluster spacecraft. Unfortunately these spacecraft were destroyed when their launch vehicle (the Ariane 5) exploded shortly after launch. Happily, both NASA and the European Space Agency decided to rebuild all four spacecraft (called Cluster-II) and they were successfully launched in the summer of 2000. This version is substantially more complicated than the Freja version, but promises to allow determination of the electric field in regions in which other techniques fail.

Selected Publications

Alfven Waves  and Acceleration of Electrons

Electron Beam Electric Field Measurements

Plasma Sheet Physics from Polar

Other Polar Science

Auroral Physics

Education

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