Advertisement

Solar Physics

, Volume 256, Issue 1–2, pp 443–462 | Cite as

The Solar Energetic Particle Event of 14 December 2006

  • T. T. von RosenvingeEmail author
  • I. G. Richardson
  • D. V. Reames
  • C. M. S. Cohen
  • A. C. Cummings
  • R. A. Leske
  • R. A. Mewaldt
  • E. C. Stone
  • M. E. Wiedenbeck
Open Access
STEREO SCIENCE RESULTS AT SOLAR MINIMUM

Abstract

The solar energetic particle event on 14 December 2006 was observed by several near-Earth spacecraft including the Advanced Composition Explorer (ACE), STEREO A and B, SOHO and Wind. An interesting feature of this event is a series of unusual fluctuations in the particle intensity that occurred during the first few hours. These fluctuations were observed inside a magnetic cloud that originated in a solar event on 13 December and show both similarities and variations at the different spacecraft. Interestingly, the most striking difference is between observations at the two closely-separated STEREO spacecraft. In particular, large fluctuations in the proton intensity were seen by the High Energy Telescope (HET) on STEREO A, and to a lesser extent at Wind and ACE, but not by the STEREO B HET. We conclude that the differences in intensity-time profiles were caused by anisotropies in the particle distribution and the different viewing directions of the individual particle telescopes. The intensity/anisotropy variations suggest that flux tubes with different particle propagation conditions existed within this magnetic cloud despite the absence of local magnetic field signatures associated with these regions. The intensity fluctuations are similar to those occasionally seen in impulsive particle events. There were also spacecraft-to-spacecraft differences during the onset of the particle event. An initial rapid onset of energetic (> 40 MeV) protons was observed by the STEREO A and B spacecraft outside the magnetic cloud, but not by spacecraft such as SOHO that were already inside the magnetic cloud at this time. The latter spacecraft observed a slower, lower intensity increase. Evidently, energetic proton propagation from the solar event to the vicinity of Earth was inhibited within the magnetic cloud compared to outside.

Keywords

Solar energetic particles STEREO Magnetic cloud 

References

  1. Cane, H.V., Reames, D.V., von Rosenvinge, T.T.: 1988, J. Geophys. Res. 93, 9555. CrossRefADSGoogle Scholar
  2. Chollet, E.E., Giacalone, J.: 2008, Astrophys. J. 688, 1368. CrossRefADSGoogle Scholar
  3. Chollet, E.E., Giacalone, J., Mazur, J.E., Al Dayeh, M.: 2007, Astrophys. J. 669, 615. CrossRefADSGoogle Scholar
  4. Fainberg, J., Osherovich, V.A., Stone, R.G., McDowall, R.J.: 1996, In: Winterhalter, D., Gosling, J. T., Habbal, S. R., Kurth, W. S., Neugebauer, M. (eds) Solar Wind Eight, AIP Conf. Proc. 382, 554. Google Scholar
  5. Farrugia, C.J., Richardson, I.G., Burlaga, L.F., Lepping, R.P., Osherovich, V.A.: 1993, J. Geophys. Res. 98, 15 497. ADSGoogle Scholar
  6. Forman, M.: 1970, J. Geophys. Res. 75, 3147. CrossRefADSGoogle Scholar
  7. Klein, L.W., Burlaga, L.F.: 1982, J. Geophys. Res. 87, 613. CrossRefADSGoogle Scholar
  8. Liu, Y., Luhmann, J.G., Müller-Mellin, R., Schroeder, P.C., Wang, L., Lin, R.P., Bale, S.D., Li, Y., Acuña, M.H., Sauvaud, J.A.: 2008, Astrophys. J. 689, 563. CrossRefADSGoogle Scholar
  9. Marsden, R.G., Sanderson, T.R., Tranquille, C., Wenzel, K.-P., Smith, E.J.: 1987, J. Geophys. Res. 92, 11 009. ADSGoogle Scholar
  10. Mazur, J.E., Mason, G.M., Dwyer, J.R., Giacalone, J., Jokipii, J.R., Stone, E.C.: 2000, Astrophys. J. 532, L79. CrossRefADSGoogle Scholar
  11. Mulligan, T., Blake, J.B., Mewaldt, R.A.: 2008, In: Proc. 30th Int. Cosmic Ray Conf. 1, 179. Google Scholar
  12. Mulligan, T., Blake, J.B., Mewaldt, R.A., Leske, R.A.: 2008, Am. Inst. Phys. Conf. Ser. 1039, 162. doi: 10.1063/1.2982440. ADSGoogle Scholar
  13. Osherovich, V.A., Fainberg, J., Stone, R.G.: 1999, Geophys. Res. Lett. 26, 401. CrossRefADSGoogle Scholar
  14. Palmer, I.D., Allum, F.R., Singer, S.: 1978, J. Geophys. Res. 83, 75. CrossRefADSGoogle Scholar
  15. Richardson, I.G., Cane, H.V.: 1995, J. Geophys. Res. 100, 23 397. CrossRefADSGoogle Scholar
  16. Richardson, I.G., Cane, H.V.: 1996, J. Geophys. Res. 101, 27 521. ADSGoogle Scholar
  17. Richardson, I.G., Reames, D.V.: 1993, Astrophys. J. Suppl. Ser. 85, 411. CrossRefADSGoogle Scholar
  18. Russell, C.T., Luhmann, J.G., Szabó, A.: 2007, In: American Geophysical Union, Fall Meeting 2007, abstract #SM34A-08. Google Scholar
  19. Tranquille, C., Sanderson, T.R., Marsden, R.G., Reinhard, R., Wenzel, K.-P.: 1987, J. Geophys. Res. 92, 6. CrossRefADSGoogle Scholar
  20. von Rosenvinge, T.T., Reames, D.V., Baker, R., Hawk, J., Nolan, J.T., Ryan, L., Shuman, S., et al.: 2008, Space Sci. Rev. 136, 391. doi: 10.1007/s11214-007-9300-5. CrossRefADSGoogle Scholar
  21. Zurbuchen, T.H., Richardson, I.G.: 2006, Space Sci. Rev. 123, 31. doi: 10.1007/s11214-006-9010-4. CrossRefADSGoogle Scholar

Copyright information

© The Author(s) 2009

Authors and Affiliations

  • T. T. von Rosenvinge
    • 1
    Email author
  • I. G. Richardson
    • 1
    • 2
  • D. V. Reames
    • 1
  • C. M. S. Cohen
    • 3
  • A. C. Cummings
    • 3
  • R. A. Leske
    • 3
  • R. A. Mewaldt
    • 3
  • E. C. Stone
    • 3
  • M. E. Wiedenbeck
    • 4
  1. 1.Code 661, NASA/Goddard Space Flight CenterGreenbeltUSA
  2. 2.CRESST and Department of AstronomyUniversity of MarylandCollege ParkUSA
  3. 3.290-17 Cahill CenterCalifornia Institute of TechnologyPasadenaUSA
  4. 4.Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaUSA

Personalised recommendations