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SECCHI and SOHO Observations of Metric type II Bursts in 2007

SECCHI and SOHO Observations of Metric type II Bursts in 2007. N. Gopalswamy, S. Jones, S. Yashiro, J. McAteer, W. Thompson, J. M. Davila, M. L. Kaiser, J.-L. Bougeret, R. A. Howard SECCHI & SWAVES Teams. STEREO SWG Nov 14 2007 CALTECH. 200. FREQUENCY MHz. m 610 km/s. m-to-km

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SECCHI and SOHO Observations of Metric type II Bursts in 2007

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  1. SECCHI and SOHO Observations of Metric type II Bursts in 2007 N. Gopalswamy, S. Jones, S. Yashiro, J. McAteer, W. Thompson, J. M. Davila, M. L. Kaiser, J.-L. Bougeret, R. A. Howard SECCHI & SWAVES Teams STEREO SWG Nov 14 2007 CALTECH

  2. 200 FREQUENCY MHz m 610 km/s m-to-km 1490 km/s 2 DISTANCE (Ro) 20 DH 1115 km/s IV III 20 1 km 539 km/s 200 0.02 TIME Type II Bursts: Earliest Indicators of Shock GROUNDBASED All CMEs: 480 km/s SEP CMEs: 1524 km/s COR1 SWAVES, WAVES N. Gopalswamy

  3. CME height at metric type II onset 1.8 Rs mkm 1.6 Rs mkm 1 2 3 4 5 1 2 3 4 5 SECCHI/COR1 FOV LASCO/C2 FOV

  4. Type II Events AR953 AR956 AR960?

  5. 20020219 Data Gap until 09:30 AR 0953 S12E16 17 GHz image from Nobeyama

  6. 2007/05/19 AR 0956 N07W06

  7. LADCO C2 2.93 4.33 5.32 Type II ended before CME first appearance in C2 COR1 saw something but the Speed is uncertain

  8. 2007/05/19 Type II & CMEs Metric Type 2 12:52 – 13:18 4.33 Ro 5.32 Ro SWAVES 13:02 -13:05

  9. 2007/05/22 AR 956 N02W40

  10. COR1 & COR2

  11. Type II 14:36-14:55 Type II ends when the CME is at 2 Rs

  12. 2007/05/23 AR 956 N02W50

  13. COR1 & COR2

  14. Type II 7:22 – 7:33

  15. 2007/06/03 AR960 S06E63 or Backsided?

  16. COR1

  17. COR2

  18. Type II 09:28-09:42 Reverse drift?

  19. Type II 09:28 – 09:42 09:26 09:36 09:27 09:56

  20. Speed increase in the metric corona Shock travels with a speed V emitting at successively lower f determined by the local plasma density: n ~ r- or f ~ r-/2 |df/dt| = V(df/dr) ~ Vf(+2)/ = Vf2 if V=const. &  =2 (Vrsnak et al., 2001) If speed varies: V~r- ~f2/ |df/dt| ~ f ( +2+2)/ = f  with  = ( +2+2)/  = 2+ for  =2  = - 0.6 for m type II (V↑) so  = 1.4  = 0.3 for km type II (V↓) so  = 2.3 Driver with a steady speed: CME  = 1.4 |df/dt| ~ f   = 2.3

  21. COR1 FOV Summary Gopalswamy et al. 2001 • All metric type II bursts have associated CMEs in overlapping spatial domain • COR1 speeds ≤ C2 speed: explains drift rate spectrum • Type II bursts associated with EUV waves • SWAVES data consistent with type II CME hierarchy • Space speed of CME to be obtained by combining STEREO A and B data

  22. Future Prospects Sudden decline at 100 Rs (Manoharan et al.) Radio observations not consistent Take limb mkm events Get CME height as a function of frequency Get CME heights when type 2 at 1 MHz Get CME heights when type 2 at 10 MHz Histograms: Deceleration starts much earlier than IPS? Explaining universal drift rate relationship 1)Take mkm limb events 2) Compute speed from first c2 points 3) Speed from all C2 points 4) Speed from all c3 points 5) Expect increase in speed and then decrease

  23. 2007/05/23 EUVI 07:22:50 07:12:50

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