1. Inner magnetospheric condition for inbound-outbound asymmetry in the CIS ion data
M. Yamauchi1, H. Nilsson1, R. Lundin1, I. Dandouras2, H. Reme2, H. Frey3, P.W. Daly4, E. Kronberg4, P.-A. Lindqvist5, M. Andr6, A. Balogh7
(1) Swedish Institute of Space Physics, Kiruna, Sweden
(2) CESR, Universite de Toulouse, Toulouse, France
(3) SSL, University of California, Berkeley, CA, USA
(4) Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany
(5) Alfven Lab., Royal Institute of Technology, Stockholm, Sweden
(6) IRF, Uppsala, Sweden
(7) Blackett Lab., ICL, London, UK

2. Sub-to several-keV ion patterns in the inner magnetosphere (near perigee of Cluster)
They are normally north-south symmetric (except seasonal effect) because these ions are bouncing between southern and northern hemispheres (cf. Cluster inbound & outbound).
(1) However, some Cluster traversals show inbound-outbound asymmetry in the ion data.
 How much are they related to substorms?
(2) In addition we found new(probably?) type of low-energy trapped ions near equator. It is similar to radiation contamination, but are different (this is the reason they have been overlooked). It is similar to plasmasphere, but probably(?) different.
We examined all perigee pass during (with caution on 2006 data).

3. Hanging stripes = “Sudare” type
9 LT
Hanging stripes = “Sudare” type

4. “sudare”
9 LT
1000 nT AU
-1000 nT AL
-2000 nT
15 hours

5. asymmetric “sudare” At post-midnight to morning:  eastward drift
 ExB drift!
 strong E
(note “sudare” itself is mainly found in night)

6. dispersed sub-keV ion = “wedge”
VB  energy (mass independent)
VExB = constant (energy  mass)

7. dispersed sub-keV ion = “wedge”
AE=qiuet
AE=just diminished
dispersed sub-keV ion = “wedge”

8. asymmetric “wedge” At morning to noon:
 “fossil” of eastward drift may suddenly appear within 1 hour as fixed place.

9. wedge-like but at several-keV (plasma sheet?) = “PS-wedge” type

10. “PS-wedge”
1000 nT
-1000 nT
AE=1 hour after substorm
-2000 nT
15 hours

11. asymmetric “PS-wedge”
At post-midnight to morning:
 eastward drift
(This is confirmed from “lower-energy than gap”)

12. Asymmetry sometimes appears as internal structure
(no model yet)
AE=qiuet

13. no preference of AE = not related to substorm?
AE=qiuet
AE=long substorm
no preference of AE = not related to substorm?

14. Internal structure
At morning to noon:
 same as “wedge”

15. low-energy structures
look at many cases reveals that no preference of AE
AE=after onset

16. asymmetric “low-energy” signature
Reason of noon peak could be because the other signature does not hide...

17. Summary of asymmetric cases
We examined ion (CIS) data for all Cluster perigee traversals during when the orbit is relatively north-south symmetric (2006 data is affected by orbit). Except seasonal effect, we found following north-south asymmetry in the inner magnetosphere.
(1) Asymmetric “Sudare” (vertical stripes of 1~10 keV ions)
 onset
(2a) Asymmetric “Wedge” (dispersed stripe at sub-keV)
(2b) Asymmetric “PS-wedge” (long stripes of few keV ions)
(2c) Asymmetric internal structure of “Wedge”
 (2a and 2c) hours after substorm activity
 (2b) early activity
(3) Asymmetric “Low-energy” (~0.1 keV ions)
 preference

18. Equatorial trapped 100 eV H+
AE=quiet
AE=small
Equatorial trapped 100 eV H+

19. Equatorial trapped 100 eV H+
At all LT except night.
 obvious candidate is plasmaspheric H+, but exists without substorm and in the afternoon.

20. Summary of 100 eV trapped H+
* Similar to but different from the radiation belt contamination.
* About 100 eV, only H+ without O+
* All LT except night
 could be “energized” plasmaspheric ions. However,
* Even observed during long quiet period
 Substorm (electric field) is unlikely related for the
transportation to the afternoon.
 Could directly be supplied from the ionosphere,
which has been observed during quiet time.

21. other substorms

22. combinations

23. Presented at Chapman Conference on Aurora (Feb 2011)
11 LT
06 LT
08 LT
07 LT
onset
SIE
SIE
SIE
onset
camera’s FOV is not optimum (aurora is active>)
18:28 UT
16:28 UT
02:40 UT
Presented at Chapman Conference on Aurora (Feb 2011)