Temperature and Density of the Plasma Sheet From Remote Observations With 1-70 keV Energetic 
Neutral Atoms

Valek, P.W., McComas, D.J., Burch, J.L., Pollock, C.J., Skoug, R.M., Thomsen, M.F., Scime, E. 


In a recent study, McComas et. al. (submitted to GRL 08/22/02) showed the first energetic
neutral atom (ENA) observations of the extended plasma sheet, taken with the Medium Energy
Neutral Atom (MENA) imager on the IMAGE spacecraft. These authors examined two magnetospheric 
storm intervals, from the period of September 21 through October 11 of 2000, and showed that 
plasma sheet loading began prior to the storms and continued under all IMF BZ orientations, 
reaching its maximum during the peaks of the storms. In this study, we further investigate 
the MENA observations from these storm intervals to create two-dimensional maps (GSM X-Y) of 
the ion temperature and density in the mid-tail plasma sheet. We then go on to show how these 
temperature and density distributions evolve over the magnetospheric storm intervals and 
interpret them in terms of plasma sheet filling, energization, and injection into the partial 
ring current. 
		   
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Fall 2002 Meeting of the American Geophysical Union
San Francisco, CA, USA, 6-10 December 2002