1. 8th Cluster Workshop, Sept 30, 2004 Cluster/DMSP Conjunctions in the Cusp Wayne Keith NASA Goddard Space Flight Center With grateful acknowledgements to M. Goldstein, T. Stubbs, D. Winningham, A. Fazakerley, and H. Rème

2. 8th Cluster Workshop, Sept 30, 2004 To what degree are cusp structures comparable from mid to low altitudes?

3. 8th Cluster Workshop, Sept 30, 2004 Finding Magnetic Conjunctions Appropriate common (mapped) coordinates Identify cusp crossings for Cluster Search Cluster crossings for DMSP satellites within 5° (~550 km) of Cluster footprint Rank quality of DMSP data Compare relative timing of particle signatures

4. 8th Cluster Workshop, Sept 30, 2004 Automated Search Procedure Mapped Cluster center-of-mass coordinates calculated via T01 and ingested into system Conjunction software run for all Cluster cusp crossing times For times when a DMSP satellite is within a “cusp box”, check their proximity using: If  < 5°, write start/stop times to a file Automatically generate DMSP plot for closest approach ±2 min

5. 8th Cluster Workshop, Sept 30, 2004 The score so far: January through August 2001 searched 73 Cluster cusp crossings 172 DMSP magnetic close-approaches 53 of which contained “good” particle signatures 35 Cluster passes contained at least one good DMSP crossing 14 good coincidence between closest approach and cusp signature 2 conjunctions under study (one in each major Cluster “cusp season”)

6. 8th Cluster Workshop, Sept 30, 2004 29 March, 2001 Cluster ~ 8 R e

7. 8th Cluster Workshop, Sept 30, 2004 Day 88 footprint map

8. 8th Cluster Workshop, Sept 30, 2004 Day 88 DMSP F-12

9. 8th Cluster Workshop, Sept 30, 2004 Day 88 DMSP F-14

10. 8th Cluster Workshop, Sept 30, 2004 Day 88 Cluster-1

11. 8th Cluster Workshop, Sept 30, 2004 Day 88 all sc

12. 8th Cluster Workshop, Sept 30, 2004 Day 88 all Cluster

13. 8th Cluster Workshop, Sept 30, 2004 14 August, 2001 Cluster ~ 5 R e

14. 8th Cluster Workshop, Sept 30, 2004 Day 226 footprint map

15. 8th Cluster Workshop, Sept 30, 2004 Day 226 all sc

16. 8th Cluster Workshop, Sept 30, 2004 Day 226 all Cluster

17. 8th Cluster Workshop, Sept 30, 2004 SD frame 1

18. 8th Cluster Workshop, Sept 30, 2004 SD frame 2

19. 8th Cluster Workshop, Sept 30, 2004 SD frame 3

20. 8th Cluster Workshop, Sept 30, 2004 SD frame 4

21. 8th Cluster Workshop, Sept 30, 2004 SD frame 5

22. 8th Cluster Workshop, Sept 30, 2004 SD frame 6

23. 8th Cluster Workshop, Sept 30, 2004 SD frame 7

24. 8th Cluster Workshop, Sept 30, 2004 SD frame 8

25. 8th Cluster Workshop, Sept 30, 2004 SD frame 9

26. 8th Cluster Workshop, Sept 30, 2004 SD frame 10

27. 8th Cluster Workshop, Sept 30, 2004 SD frame 11

28. 8th Cluster Workshop, Sept 30, 2004 SD frame 12

29. 8th Cluster Workshop, Sept 30, 2004 SD frame 13

30. 8th Cluster Workshop, Sept 30, 2004 Conclusions Cluster/DMSP conjunctions identified using combination of automated and manual search techniques Mapped Cluster cusp location usually poleward of DMSP cusp location Cusp appears narrow in Invariant Latitude and extended in Magnetic Local time Cusp structures appear similar in general, but Cluster data requires more study