1. Plasma Density Structures in the Inner Magnetosphere Derived From RPI Measurements B. Reinisch 1, X. Huang 1, P. Song 1, J. Green 2, S. Fung 2 V. Vasyliunas 3, and D. Gallagher 4 1 University of Massachusetts Lowell 2 NASA Goddard Space Flight Center 3 Max-Planck Institut für Aeronomie, Lindau 4 NASA Marshal Space Flight Center IMAGE Science Meeting 4 May 2003 Lowell, Massachusetts

2. 2 Areas of Research Plasmaspheric density model. 2-D plasmaspheric snapshots Storm-time depletion and refilling Polar region model 2-D polar region snapshots Magnetospheric field line distortion Wave propagation theory and method development

3. 3 Empirical Magnetospheric Density Distribution Average 2000-2001 L = 7 6 5 June 2001 0800 LT March 2001 1200 LT

4. 4 PROPAGATION ALONG THE FIELD LINE

5. 5 Profile Inverted from the scaled Traces

6. 6 One pass of IMAGE on June 8, 2001

7. 7 Profile Fitting Function N e0 equatorial density  flatness (~1)  steepness inv invariant latitude

8. 8 Modeled two dimensional density distribution for MLT=8.0 on June 8, 2001

9. 9 During Storm L S = 2.84 Measured profile Quiet-time model

10. 10 Refilling ratio (N e0 /N e0,quiet ) as function of t and L Storm Full Depleted ?

11. 11 Figure 2 (a) is a scaled X-mode frequency–virtual range trace and (b) is the derived N e -true range profile from the trace using the inversion technique described above. X-Trace (a) (b)

12. 12 Figure 4 (A) bin-averaged N e vs. R. The error bars correspond to the N e standard deviation of densities from each corresponding average, (B) bin-averaged N e /R  vs. Kp,.

13. 13 Figure 6. Comparison of polar region N e models [Persoon et al, 1983; Gallagher et al., 2000], DE 1 in-situ particle measurements and the RPI-derived model for Kp = 0, 3,and 5 (along a magnetic latitude of 88  ). RPI

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19. 19 The Arc Length D ES for a Dipole Field D ES

20.  R = D ES = 2.0 2 April 2002 0.25 MLT --- L S =3.36, S = -17.1º  R = D ES = 2.0 RRRR

21.  R = D ES = 0.5 9 March 2002 1.71 MLT --- L S =4.12, S = 3.87º  R = D ES = 0.5 RRRR

22. 22  R = 2.5, D ES = 2.1   = 0.4 Re A Stretched Field Line 02 Mar 2001 1.85 MLT --- L S =2.48, S =-23.5º  R = 2.5, D ES = 2.1   = 0.4 Re RRRR

23. 23  R = 4.5, D ES = 5.2   = 0.7 Re A Compressed Field Line 23 Mar 2001 13.35 MLT --- L S =3.70, S =37.4º  R = 4.5, D ES = 5.2   = 0.7 Re RRRR

24. 24 Summary Instantaneous measurement of plasma distribution along geomagnetic field line (a validated method) Database for empirical plasmapheric models and algorithm exists (require more detailed analyses, L-shell, LT, Dst, SW, IMF dependences) Time series of plasmaspheric filling factor can be used to study storm-time depletion-refilling processes (tested in one case) 2-D plasmaspheric density snapshots are available (tested two cases, one with convection tail) Polar empirical model for Kp and R developed (Lat. LT, SW, IMF dependences) 2-D polar snapshots show structures (require more event studies, possibly with other instruments) Discrepancy between the observed and model predicted equatorial field line lengths are found (require systematic studies) Wave propagation theory (require further development) Density inversion for Z mode traces (not started yet)

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