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Evolution of Interplanetary Coronal Mass Ejections for Different Solar Wind Conditions

Departamento de Física Juan José Giambiagi . Evolution of Interplanetary Coronal Mass Ejections for Different Solar Wind Conditions. Dasso S. 1,2 , Gulisano A.M. 1 , Demoulin P. 3 , Ruiz M.E. 1 & Marsch E. 4

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Evolution of Interplanetary Coronal Mass Ejections for Different Solar Wind Conditions

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  1. Departamento de FísicaJuan José Giambiagi Evolution of Interplanetary Coronal Mass Ejectionsfor Different Solar Wind Conditions Dasso S.1,2, Gulisano A.M.1, Demoulin P.3,Ruiz M.E.1& Marsch E.4 1Instituto de Astronomía y Física del Espacio (IAFE), Universidad de Buenos Aires (UBA), Argentina 2 Departamento de Física, Facultad de Ciencias Exactas y Naturales, UBA, Argentina 3Observatoire de Paris, LESIA, Meudon, France 4Max-Planck-Institut für Sonnensystemforschung, Lindau, Germany International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  2. An ICME is an expanding flux rope in the SW How much can be affectedits expansion by local environment conditions? Outline Expansion from analysis of different ICMEs at different solar distances D Expansion fromanalysis of a MC at fixed D (non-dimensional rate along S/C path) Comparison of expansion for different SW conditions: -MC in a clean SW / Overtaken MC by fast SW Anisotropy of expansion (axial and radial expansion) International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  3. Evolution of ICMEs: key parameters from different events observed at different solar distances D (good for global expansion) [From Liu et al., Plan. & Space Sci. 2005] S~D0.9, Np~D-2.3, T~D-0.3, B~D-1.4 Considering other studies (more events): S~D0.8±0.1[e.g., Bothmer & Schwenn ‘98; Leitner et al. JGR‘07] Is the large dispersion due to the evolution in different ambients? International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  4. NOT PERTURBED Example of MC not perturbed, (~ linear velocity profile for full MC) Vx Vc t Example of MC perturbed at the rear(perturbed profile of the velocity) PERTURBED

  5. Dimensionless local expansion coefficient [Demoulin et al., SolPhys, 2008; Demoulin & Dasso, A&A, 2009; Gulisano et al., A&A, in press 2009] Globally: S=S0(D/D0)m use dS/dtcan't use dS/dt S=S0(D/D0) Helios 1&2 MCs For Not Perturbed Vx ~ dS/dt = mVc S/D, = D Vx /(t Vc2) and S~t Vc =>N~ m For Perturbed  = D Vx /(tVc2) ~D Vx/(SVc) =>O~D0 mD1-m/(S0Vc)Vx NoPerturbed ~ 0.9 Not Perturbed MCs present no correlation, while Perturbedones are correlated

  6. Black solid line corresponds to the expected global expansion S ~ Dm Green line to an example of Not Perturbed MC Blue dashed line to one possible example of Perturbed MC International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  7. Radial and axial expansion: different expansion rates? Back !! Radial expansion due to solar wind pressure decay Axial expansion due to connectivity to the Sun (self-similar: m=1) Adapted from [Zurbuchen & Richardson, Space Science Rev, 2006] International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  8. Modelling the magnetic flux rope From in situ observed B possible to ‘orient’ the flux rope & compare with models  e.g., MV International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  9. We preliminary found a nearly isotropic expansion cos()=zcloud•xGSE Helios 1 & 2 MCs International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  10. Summary and Conclusions •Magnetic Clouds are expanding structures as consequence of the decrease of the solar wind pressure (ambient) and connectivity to the Sun •A non-dimensional local expansion rate (=VD/(tVc2)) can be defined and determined from single point (1 S/C) in situ observations •For no-overtakenMCs, the observed local expansion () was in a full agreement with the global expansion (m~0.8±0.1) •Local expansion can be significantly affected by flows that overtake MCs: SW-cloud or cloud-cloud interactions [e.g. Dasso et al., JGR’09] •Anisotropy in MC expansion rates is expected (axial and radial expansion are due to very different physical mechanisms) •However, we preliminary (work in progress) found that is nearly isotropic (statistically supporting connectivity to the Sun of MC legs for our sample) Thank you very much for your attention !!! International Living With a Star (ILWS), October 4-9, 2009, Ubatuba, Brazil

  11. Additional Slides

  12. B~D-1.8 Better determination of exponents (more events): S~D0.8±0.1[e.g., Bothmer & Schwenn ‘98; Leitner et al. JGR‘07] Improvements Moving boundary model [Demoulin & Dasso A&A‘09]: For SW pressure decay as Psw(D)~D-np, global expansion S~ Dnp/4 ~ D0.7 [Demoulin talk SW12] Different MCs observed at different solar distances D (good for global expansion) Modeling evolution of MCs from assuming: (i) conservation of magnetic fluxes and H (ii) isotropic self-similar expansion np~D-2.8 S~D0.97 S~D, np~D-3, B~D-2 Large uncertainties (only a few observed events) [From Kumar & Rust, JGR 1996] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  13. Non-dimensional expansion rate for local expansion (no model is assumed) [Demoulin et al., Sol Phys’08; Gulisano et al., poster SW12] Based on observations: S(D)~S0 (D/D0)m, If dS/dt~V then ~m [Demoulin talk SW12] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France Learning from 1 S/C observations (fixed D) of one event (model and ) From Nakwacki et al. [COLAGE’07, Mexico] Expansion from fitting model to Vx t [e.g., Farrugia et al., JGR’95; Nakwacki et al., JASTP’08] V T≈3-3.3 days <Vx,cloud>=-794km/s Radial expansion rate: dR/dt  (0.03-0.045) AU/day tc: center V(tc)

  14. Same event observed at 1AU and 5.4AU [see more in Nakwacki et al., poster SW12] ACE Ulysses SACE(D=1AU)=0.22AU ACE=0.70 SUlysses(D=5.4AU)=0.63AU Ulysses=0.65 Observations according with the expected increment of size: Sexpected,Ulysses ~SACE 5.4 ~ [0.62-0.72]AU Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  15. Pealing flux ropes via magnetic reconnection By,cloud Oct 20, 01:36UT Oct 19, 07:26UT Oct 19, 17:37UT Cancelation of Fy,cloud at a magnetic discontinuity [from Dasso et al., A&A 2006] y Cumulative flux Fy/L x Xin From B=0 and invariance of B along the main axis of the cloud (valid to a general 2D-shape!): Different end boundaries chosen by previous authors [Lepping et al., JGR’97; Larson et al., GRL’97; Janoo et al., JGR’98] Start: Oct 18, 1995 at 18:58UT

  16. Expansion of a partially pealed flux rope that is overtaken by SW Back The flux rope was partially pealed from its front. However, the ‘back’ still ~ as before reconnection, showing ~ properties of a flux rope and not of SW OVERTAKEN MC Back! =0.44±0.1 < 0.7 Adapted from [Zurbuchen & Richardson, Space Science Rev, 2006] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  17. Example with reconnection in the MC front, but non-overtaken ~18hs MC Reconnected flux: ~ 20%-30% of total [Dasso et al., Sol Phys, ‘07] MC This event: =0.7±0.1 Same as typical value for no overtaken MCs without reconnection[See Gulisano et al., poster SW12; Demoulin talk SW12] Thus, typical value of for no overtaken events, even for reconnection conditions! size~0.26AU

  18. Cloud-cloud interaction Two filament eruptions H MC1: MC ~ -15°, MC ~ 125° ~ 0.08 AU MC2: MC ~ 55° & MC ~ 120° [From Dasso et al., JGR 2009] ~ 0.4 AU MC1: Typical coherent rotation of B (flux rope) but ... Compressed  no typical expansion (it is significantly pushed by MC2) no typical linear profile of V and no typical low Tp and low  MC2: huge MC, large impact parameter Typical expansion factor (=0.7±0.1) MC2 is almost not affected by MC1 (relative size) Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  19. Transients are ejected from the Sun toward the SW • A subset of ICMEs can be observed as ‘Magnetic Clouds’ (MCs) in the SW • Observed properties: • - Low Tp • - Smooth and larger rotation of enhanced B • - Low proton plasma p From [Zurbuchen & Richardson, Space Science Rev, 2006] • Fast MCs driven a shock wave (and a turbulent sheath of large n) • Cold structures (low Tp) • e-s flows along B (>100eVs): proxy of magnetic connectivity • Smooth and large coherent rotation of B (helical structures), increased respect to the SW • Low plasma beta (p) Fmag Snow thrower effect Parker spiral B

  20. Evolution of MCs in the heliosphere (more cases) from Leitner et al. [JGR’07], in agreement with previous studies [Bothmer & Schwenn, AnnGeophys 1998] Inner heliosphere Tp~r- 1.2.±0.7 Inner heliosphere np~r- 2.4±0.5 np~r- 2.6±0.1 Tp~r- 1.6±0.2 Inner heliosphere D~r1.1.±0.4 Inner heliosphere B0~r- 1.6±0.4 B0~r-1.3±0.1 D~r0.6±0.1 4th El Leoncito Solar Physics School, El Leoncito San Juan & La Punta San Luis, Argentina, Nov 24-29, 2008

  21. Spacecraft Observations (MFI/Wind): MC observed on Oct 18-19, 1995 • Coherent Rotation of B • Velocity profile flat (old cloud without significant expansion) • Shock wave in front (A) • Magnetic hole (B): a signature of reconnected field? • Strong Alfvén waves activity after the MC From Lepping et al. [JGR, 1997]

  22. Modelling the magnetic flux rope From in situ observed B possible to ‘orient’ the flux rope & compare with models  IAU Symposium 257 Universal Heliophysical Processes, Ioannina, Greece, Sep 15-19, 2008

  23. NOT OVERTAKEN [see more in Gulisano et al., poster SW12] OVERTAKEN Expanding MC in a ‘clean’ SW Observed by Helios 1 on Jan 7, 1975 Expanding MC while fast SW is overtaken it Observed by Helios 1 on Jun 23, 1980

  24. Magnetic Reconnection: More ingredients than MHD are needed to evolution of B enlarged in IP Hall Effect: • From MHD eqs: , then B is frozen-in to the electron fluid • Electrons travel faster in helical motion, thus B is accelerated respect to MHD • Current sheet is tinnier and reconnection is more efficient From numerical simulations of 2.5D incompressible HMHD [Morales et al., JGR’05]

  25. 2nd studied case: Nov 2004 From Harra et al. [Sol Phys 2007] • We study this MC, which is in very strong expansion • Decreasing V • Decreasing B • There are different end boundaries, according with different proxies (criteria)

  26. with axial expansion No axial expansion [Dasso et al, SolPhys 2007, in press] Now, we consider expansion effects on flux cancellation observed z dx modelled x Cloud axis: =-10° =275°

  27. Two interacting ICMEs [From Dasso et al., JGR 2009] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  28. Two filament eruptions H ICME MC2 MC2 MC1 MC1 Texp axial B spacecraft path across MCs axial B MC overtaken by another MC [From Dasso et al., JGR 2009] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  29. [From Dasso et al., JGR 2009] Solar Wind 12, June 21-June 26, 2009, Saint Malo, France

  30. Grad-Shafranov (Moestl) • Two clouds, • The first one: the satellite is crossing • near the axis of the MC • For the second it crosses far away, • the impact parameters are large, • The MVariance method is not adapted

  31. Ospan observations for the flare at 13:30 UT (12:48-14:00UT) Hebe • First event • C1.5 Xray flare (OSPAN) • TRACE 195 • Second event • M8.0 X ray flare (BBSO)

  32. The events at the Sun • EIT 195 Å image on 13 May at 11:42 UT. • Magnetic linear force free model of AR 10759 before the M 8.0 flare • = -1.6 10-2 Mm-1 Negative magnetic helicity in the AR field and surroundings TRACE 195 Å image on 14 May at 12:45 UT. Two post-flare arcades are visible. • Negative helicity on the Sun and in the MCs

  33. Open and closed fields in magnetic clouds Suprathermal (320 eV) electron pitch angle distributions for 8 Nov 04 • Counterstreaming suprathermal electrons indicate field lines connected to the Sun at both ends (closed) • On average, clouds are nearly half open open closed Shodhan et al. [2000] magnetic cloud

  34. Gosling, Birn, and Hesse [1995] Crooker, Gosling, and Kahler [2002] Opening ICMEs by Interchange Reconnection • At CME liftoff • a. Partial disconnection (closed-closed) creates flux rope coil • b. Interchange reconnection (closed-open) opens coil • As ICME moves out into heliosphere • Interchange reconnection at Sun may continue to open field lines

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