08/05/2011 18:00:00 UTC

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Comment Section

  • A "big" event of having everything: halo CME in C2, halo CME in COR2 A, M9-class flare, strong waves in coronal images
  • In-situ: only show shock structure; the CME ejectum might have missed the Earth
  • The marks on the GMU plots are wrong. This is not an MC event. The starting and ending times of MC should be removed (Jie Zhang 01/26/2017)

Image Data

In-Situ Data

Plot sw mag plasma 2011080500.png Plot sw mag 2011080500.png Plot sw vel 2011080500.png
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

Remote observations and modeling results

From Vladimir Slemzin: We present a study of several solar wind transients observed by ACE on 4 – 7 August 2011, which caused a geomagnetic storm with Dst = −110 nT (Rodkin et al., 2017). Using the observational data of ACE, SDO/AIA and SOHO/LASCO and MHD modeling of the flux rope expansion, it was shown that the first ICME of 5 August 2011 was produced by the CME of 2 August 2011, 05:54 UT. Using the results of the plasma diagnostics and MHD modeling, we calculated the ejecta ion composition taking into account the processes of cooling, expansion, ionization, and recombination of ther CME plasma up to the frozen-in region.

By matching the calculated ion composition parameters of the CME with those measured in situ, we estimated a probable heating flux acting on the CME plasma during its expansion in the low corona.

Two Figures[1] illustrate evolution of the flux rope and CME plasma parameters at the first stage of their expansion obtained from MHD modeling and observations.

Reference: D. Rodkin F. Goryaev, P. Pagano, G. Gibb, V. Slemzin, Y. Shugay, I. Veselovsky, D.H. Mackay “Origin and Ion Charge State Evolution of Solar Wind Transients during 4 – 7 August 2011” published in Solar Phys (2017), 292:90, DOI 10.1007/s11207-017-1109-0.