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Solar Physics

, 259:227 | Cite as

Relation Between Type II Bursts and CMEs Inferred from STEREO Observations

  • N. GopalswamyEmail author
  • W. T. Thompson
  • J. M. Davila
  • M. L. Kaiser
  • S. Yashiro
  • P. Mäkelä
  • G. Michalek
  • J.-L. Bougeret
  • R. A. Howard
STEREO Science Results at Solar Minimum

Abstract

The inner coronagraph (COR1) of the Solar Terrestrial Relations Observatory (STEREO) mission has made it possible to observe CMEs in the spatial domain overlapping with that of the metric type II radio bursts. The type II bursts were associated with generally weak flares (mostly B and C class soft X-ray flares), but the CMEs were quite energetic. Using CME data for a set of type II bursts during the declining phase of solar cycle 23, we determine the CME height when the type II bursts start, thus giving an estimate of the heliocentric distance at which CME-driven shocks form. This distance has been determined to be ∼1.5R s (solar radii), which coincides with the distance at which the Alfvén speed profile has a minimum value. We also use type II radio observations from STEREO/WAVES and Wind/WAVES observations to show that CMEs with moderate speed drive either weak shocks or no shock at all when they attain a height where the Alfvén speed peaks (∼3R s – 4R s). Thus the shocks seem to be most efficient in accelerating electrons in the heliocentric distance range of 1.5R s to 4R s. By combining the radial variation of the CME speed in the inner corona (CME speed increase) and interplanetary medium (speed decrease) we were able to correctly account for the deviations from the universal drift-rate spectrum of type II bursts, thus confirming the close physical connection between type II bursts and CMEs. The average height (∼1.5R s) of STEREO CMEs at the time of type II bursts is smaller than that (2.2R s) obtained for SOHO (Solar and Heliospheric Observatory) CMEs. We suggest that this may indicate, at least partly, the density reduction in the corona between the maximum and declining phases, so a given plasma level occurs closer to the Sun in the latter phase. In two cases, there was a diffuse shock-like feature ahead of the main body of the CME, indicating a standoff distance of 1R s – 2R s by the time the CME left the LASCO field of view.

Keywords

Coronal mass ejections Type II radio bursts Shocks Flares Dynamic spectrum 

References

  1. Aguilar-Rodriguez, E., Gopalswamy, N., MacDowall, R.J., Yashiro, S., Kaiser, M.L.: 2005, In: Proceedings of Solar Wind 11/SOHO 16, 393. Google Scholar
  2. Bougeret, J.-L., Kaiser, M.L., Kellogg, P.J., Manning, R., Goetz, K., Monson, S.J., Monge, N., et al.: 1995, Space Sci. Rev. 71, 231. CrossRefADSGoogle Scholar
  3. Bougeret, J.L., Goetz, K., Kaiser, M.L., Bale, S.D., Kellogg, P.J., Maksimovic, M., Monge, N., et al.: 2008, Space Sci. Rev. 136, 487. CrossRefADSGoogle Scholar
  4. Brueckner, G.E., Howard, R.A., Koomen, M.J., Korendyke, C.M., Michels, D.J., Moses, J.D., Socker, D.G., et al.: 1995, Solar Phys. 162, 357. CrossRefADSGoogle Scholar
  5. Cliver, E.W., Nitta, N.V., Thompson, B.J., Zhang, J.: 2004, Solar Phys. 225, 105. CrossRefADSGoogle Scholar
  6. Gopalswamy, N.: 2006a, J. Astrophys. Astron. 27, 243. CrossRefADSGoogle Scholar
  7. Gopalswamy, N.: 2006b, In: Gopalswamy, N., Mewaldt, R., Torsti, J. (eds.) Solar Eruptions and Energetic Particles, Geophys. Monogr. Ser. 165, AGU, Washington, 207. CrossRefGoogle Scholar
  8. Gopalswamy, N., Kaiser, M.L.: 2002, Adv. Space Res. 29(3), 307. CrossRefADSGoogle Scholar
  9. Gopalswamy, N., Thompson, B.J.: 2000, J. Atmos. Solar Terr. Phys. 62, 1457. CrossRefADSGoogle Scholar
  10. Gopalswamy, N., Lara, A., Lepping, R.P., Kaiser, M.L., Berdichevsky, D., St. Cyr, O.C.: 2000, Geophys. Res. Lett. 27, 145. CrossRefADSGoogle Scholar
  11. Gopalswamy, N., Lara, A., Kaiser, M.L., Bougeret, J.-L.: 2001a, J. Geophys. Res. 106, 25261. CrossRefADSGoogle Scholar
  12. Gopalswamy, N., Yashiro, S., Kaiser, M.L., Howard, R.A., Bougeret, J.-L.: 2001b, J. Geophys. Res. 106, 29219. CrossRefADSGoogle Scholar
  13. Gopalswamy, N., Aguilar-Rodriguez, E., Yashiro, S., Nunes, S., Kaiser, M.L., Howard, R.A.: 2005, J. Geophys. Res. 110, A12S07. CrossRefGoogle Scholar
  14. Gopalswamy, N., Yashiro, S., Xie, H., Akiyama, S., Aguilar-Rodriguez, E., Kaiser, M.L., Howard, R.A., Bougeret, J.-L.: 2008a, Astrophys. J. 674, 560. CrossRefADSGoogle Scholar
  15. Gopalswamy, N., Yashiro, S., Akiyama, S., Mäkelä, P., Xie, H., Kaiser, M.L., Howard, R.A., Bougeret, J.-L.: 2008b, AnnGeo 26, 3033. ADSGoogle Scholar
  16. Holman, G.D., Pesses, M.E.: 1983, Astrophys. J. 267, 837. CrossRefADSGoogle Scholar
  17. Howard, R.A., Moses, J.D., Vourlidas, A., Newmark, J.S., Socker, D.G., Plunkett, S.P., Korendyke, C.M., et al.: 2008, Space Sci. Rev. 136, 67. CrossRefADSGoogle Scholar
  18. Kaiser, M.L., Kucera, T.A., Davila, J.M., St. Cyr, O.C., Guhathakurta, M., Christian, E.: 2008, Space Sci. Rev. 136, 5. CrossRefADSGoogle Scholar
  19. Leblanc, Y., Dulk, G.A., Bougeret, J.-L.: 1998, Solar Phys. 183, 165. CrossRefADSGoogle Scholar
  20. Mann, G., Klassen, A., Classen, H.T., Aurass, H., Scholz, D., MacDowall, R.J., Stone, R.G.: 1996, Astron. Astrophys. 119, 489. ADSGoogle Scholar
  21. Mann, G., Klassen, A., Estel, C., Thompson, B.J.: 1999, In: Vial, J.-C., Kaldeich-Schmann, B. (eds.) Proc. of 8th SOHO Workshop, 477. Google Scholar
  22. Mann, G., Klassen, A., Aurass, H., Classen, H.-T.: 2003, Astron. Astrophys. 400, 329. CrossRefADSGoogle Scholar
  23. MacQueen, R.M., Burkepile, J.T., Holzer, T.E., Stanger, A.L., Spence, K.E.: 2001, Astrophys. J. 549, 1175. CrossRefADSGoogle Scholar
  24. Michalek, G., Gopalswamy, N., Xie, H.: 2007, Solar Phys. 246, 409. CrossRefADSGoogle Scholar
  25. Newkirk, G.A.: 1967, Ann. Rev. Astron. Astrophys. 5, 213. CrossRefADSGoogle Scholar
  26. Pohjolainen, S., van Driel-Gesztelyi, L., Culhane, J.L., Manoharan, P.K., Elliott, H.A.: 2007, Solar Phys. 244, 167. CrossRefADSGoogle Scholar
  27. Reiner, M.J., Kaiser, M.L., Fainberg, J., Stone, R.G.: 1998, J. Geophys. Res. 103, 29651. CrossRefADSGoogle Scholar
  28. Saito, K.: 1970, Ann. Tokyo Astron. Obs. Ser. 2 12, 53. Google Scholar
  29. Saito, K., Poland, A.I., Munro, R.H.: 1977, Solar Phys. 55, 121. CrossRefADSGoogle Scholar
  30. Sheeley, N.R. Jr., Wang, Y.-M., Hawley, S.H., Brueckner, G.E., Dere, K.P., Howard, R.A., et al.: 1997, Astrophys. J. 484, 472. CrossRefADSGoogle Scholar
  31. Thompson, B.J., Cliver, E.W., Nitta, N., Delannée, C., Delaboudinière, J.-P.: 2000, Geophys. Res. Lett. 27, 1431. CrossRefADSGoogle Scholar
  32. Vršnak, B.: 2001, Solar Phys. 202, 173. CrossRefADSGoogle Scholar
  33. Vršnak, B., Aurass, H., Magdalenic, J., Gopalswamy, N.: 2001, Astron. Astrophys. 377, 321. CrossRefADSGoogle Scholar
  34. Vršnak, B., Magdalenić, J., Aurass, H., Mann, G.: 2002, Astron. Astrophys. 396, 673. CrossRefADSGoogle Scholar
  35. Vršnak, B., Cliver, E.: 2008, Solar Phys. 253, 215. CrossRefADSGoogle Scholar
  36. Wood, B.E., Karovska, M., Chen, J., Brueckner, G.E., Cook, J.W., Howard, R.A.: 1999, Astrophys. J. 512, 484. CrossRefADSGoogle Scholar
  37. Zhang, J., Kundu, M.R., White, S.M., Dere, K.P., Newmark, J.S.: 2001, Astrophys. J. 561, 396. CrossRefADSGoogle Scholar

Copyright information

© US Government 2009

Authors and Affiliations

  • N. Gopalswamy
    • 1
    Email author
  • W. T. Thompson
    • 1
  • J. M. Davila
    • 1
  • M. L. Kaiser
    • 1
  • S. Yashiro
    • 2
  • P. Mäkelä
    • 3
  • G. Michalek
    • 3
  • J.-L. Bougeret
    • 4
  • R. A. Howard
    • 5
  1. 1.NASA Goddard Space Flight CenterGreenbeltUSA
  2. 2.InterferometricsHerndonUSA
  3. 3.The Catholic University of AmericaWashingtonUSA
  4. 4.Paris ObservatoryMeudonFrance
  5. 5.Naval Research LaboratoryWashingtonUSA

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