C.H. Mandrini 1 and S. Dasso 1,2

1. Combined analysis  and modeling of in situ and remote sensing observations: MCs and their solar sources C.H. Mandrini1 and S. Dasso1,2 1 Instituto de Astronomía y Física del Espacio, Buenos Aires, Argentina 2 Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina In collaboration with: G. Attrill, P. Démoulin, A. Gulisano, M.L. Luoni, M.S. Nakwacki, S. Pohjolainen, L. van Driel-Gesztelyi…

2. Modelling the magnetic flux rope possible to find the orientation of the flux rope axis → rotate to “natural” flux rope coordinates → compare with models From in situ observed B  e.g., MV

3. z R L Surface for Fz Surface for F Global MHD quantities from models Linear Force-Free Field (Lundquist, 1950) • (r)=d/dz=B(r)/rBz(r): amount of magnetic field twist • 0=(r~0) • B0 is the magnetic field intensity at the cloud axis Free parameters of the model fitted to observed B z

4. Different models - Main parameters: {R, 0 and B0}

5. Estimation of H - modeling observations H/L in 1042Mx2/AU Models with different (r). linear FFF [Lundquist, 1950]:* constant  FFF [Gold&Hoyle, 1960]:  constant J [Hidalgo et al., 2003]: Jincreasing with r [Cid et al., 2002]:+ Even when (r) is very different, H does not depend significantly on the model (Dasso et al.,2003; Gulisano et al., 2005; Dasso et al., 2005) (Gulisano et al., 2005)

6. Global quantities from a Direct Method (no model) Assuming cylindrical and translation symmetry (no assumption on the specific magnetic distribution) it is possible to estimate F and H directly from B observations: y x (Dasso et al., 2005) • H can be expressed as the contribution of azimuthal B weighted by accumulated axial Flux (as expected from geometrical interpretation of H)! • The field inside the unobserved core (if p0) can be modeled; but correction for F and H are low:  ~ (p/R)2 • Thus, 10% in p/R will introduce an error of 1% in F and H

7. Estimation of H: direct method and models H/L in 1041 Mx2/AU (Dasso et al., 2005)

8. - + interplanetary medium corona double dimmings Axial flux Comparison with solar events: Magnetic flux in coronal dimmings and MC flux If ejection  mainly field line expansion Magnetic flux in dimmings ~ axial MC flux Dimmings after 12 May, 1997, flare/CME (top) – Overlaid on MDI (bottom) From Webb et al. (2000)

9. Magnetic flux in dimmings and MC flux The small eruptive solar events on 11 May, 1998 EIT 284, 10 – 12 May 1998 Small MC from 22:00 UT on May 15 to 01:50 UT on May 16 Solar wind speed ~350±50 km/s  travel time is ~119±17 hs  = 59°  = 172° from a MV method May 1998 eventFdimmings~ 13 ± 2x 1019 Mx Fcloud = 10 - 20 x 1019 Mx Fzcloud = 1.3 x 1019 Mx FAR = 32. x 1019 Mx (maximum) L ~ 0.5 – 1 AU  considering that the small MC was detached from the Sun ~1 day after ejection + distance traveled by Alfvèn waves (~100 km/s) in 3.5 days (~0.2 AU). Mandrini et al. (2005)

10. Magnetic flux in dimmings and MC flux Long duration event 12 May, 1997 1 Dimmings intensity boundary halfway between the quiet Sun and a coronal hole. Base difference EIT image at maximum dimming extension 05:41 –03:59 UT. Contours: red  orange  white show the expansion and yellow  green blue the contraction of dimmings. 2 MC from 10:00 UT on May 15 to 01:00 UT on May 16  = -2°  = 114° from a MV method May 1997 eventFdimmings~ 21 ± 7x 1020 Mx Fcloud = 19 ± 9 x 1020 Mx Fzcloud = 5 ± 0.8 x 1020 Mx FAR = 48 x 1020 Mx L ~ 1.5 AU  flux tube connected at one leg (Webb et al. 2000), probable disco-nnection on May14, 12:00 UT, recovery dimming region 1. Fzcloud ~ 10% FAR for typical AR (as in statistical studies by Lepping et al. (1990), Zhao et al. (2001), Watari et al. (2001)) Attrill et al. (2006)

11.  Comparison of fluxes Transformation  arcade to flux rope (van Ballegoijen & Martens 19889, Gosling 1990, Amari et al. 2003 ….) Unstable configuration Reconnection => larger erupting flux rope Field line expansion => dimming formation Magnetic flux in dimmings at maximum extension axial + azimuthal MC flux 

12. Coronal and MC helicity quantification The small eruptive solar events on 11 May, 1998 Hcor relative coronal magnetic helicity using xB=B red,  = -0.08 Mm-1 green+blue,  = -0.11 Mm-1 TRACE 195 at 00:38 UT on May 11 with MDI isocontours of the field at 00:03 UT (positive: white, negative: black) May 1998 event 2.3 x 1039 Mx2 |Hcor|  3.1 x 1039 Mx2 1.5 x 1039 Mx2 |Hcloud|  3.0 x 1039 Mx2 L ~ 0.5 – 1 AU  considering that the small MC was detached from the Sun ~1 day after ejection + distance travelled by Alfvèn waves (~100 km/s) in 3.5 days (~0.2 AU). Mandrini et al. (2005)

13. L ~ 1.2 AU Coronal and MC helicity quantification The C6.7 LDE on 14 October, 1995 Luoni et al. (2005) Kitt Peak magnetogram - SXT full disk images Pitch angle spectrograms of high energy electrons. Magnetic connection or disconnec-tion (along the negative leg) to the Sun indicated below (Larson et al., 1997)  = -5°  = 203° from a MV method October 1995 event 3 x 1042 Mx2 Hcor 6 x 1042 Mx2 3.6 x 1042 Mx2  Hcloud 7.2 x 1042 Mx2 L ~ 1.2 – 2.4 AU  estimated from in situ observations of impulsive electrons, flux tube connected to the Sun at one leg (Larson et al. 1997).

14. Summary from case studies The solar mag. configuration orientation and MC axis agree in general. If not kink instability or deflection HCS. The magnetic helicity sign in MCs agrees with that of their solar source regions. The coronal magnetic helicity variation (before – after the ejection) quantitatively agrees with the MC magnetic helicity content for the estimated MC lengths. If not, lengths are wrong? magnetic reconnection in the IP? The MC axial magnetic flux is lower than the azimuthal flux (less than 10 times) for the estimated MC lengths. In general, the axial flux ~ 10% of the flux in the solar AR source. The MC azimuthal + axial fluxesagree with the photospheric “open” flux in the dimming regions.

15. Rodriguez, L., et al.\ 2009, Space Weather, 7, 6003 Dasso, S., et al.\ 2009, Journal of Geophysical Research (Space Physics), 114, 2109 D{\'e}moulin, P., Nakwacki, M.~S., Dasso, S., \& Mandrini, C.~H.\ 2008, \solphys, 250, 347 Nakwacki, M.~S., Dasso, S., Mandrini, C.~H., \& D{\'e}moulin, P.\ 2008, Journal of Atmospheric and Solar-Terrestrial Physics, 70, 1318 Rodriguez, L., et al.\ 2008, Annales Geophysicae, 26, 213 Dasso, S., Nakwacki, M.~S., D{\'e}moulin, P., \& Mandrini, C.~H.\ 2007, \solphys, 244, 115 Harra, L.~K., et al.\ 2007, \solphys, 244, 95 Mandrini, C.~H., Nakwacki, M.~S., Attrill, G., van Driel-Gesztelyi, L., D{\'e}moulin, P., Dasso, S., \& Elliott, H.\ 2007, \solphys, 244, 25 Gulisano, A.~M., Dasso, S., Mandrini, C.~H., \& D{\'e}moulin, P.\ 2007, Advances in Space Research, 40, 1881 Attrill, G., Nakwacki, M.~S., Harra, L.~K., van Driel-Gesztelyi, L., Mandrini, C.~H., Dasso, S., \& Wang, J.\ 2006, \solphys, 238, 117

16. Dasso, S., Mandrini, C.~H., D{\'e}moulin, P., \& Luoni, M.~L.\ 2006, \aap, 455, 349 Gulisano, A.~M., Dasso, S., Mandrini, C.~H., \& D{\'e}moulin, P.\ 2005, Journal of Atmospheric and Solar-Terrestrial Physics, 67, 1761 Luoni, M.~L., Mandrini, C.~H., Dasso, S., van Driel-Gesztelyi, L., \& D{\'e}moulin, P.\ 2005, Journal of Atmospheric and Solar-Terrestrial Physics, 67, 1734 Mandrini, C.~H., Pohjolainen, S., Dasso, S., Green, L.~M., D{\'e}moulin, P., van Driel-Gesztelyi, L., Copperwheat, C., \& Foley, C.\ 2005, \aap, 434, 725 Dasso, S., Gulisano, A.~M., Mandrini, C.~H., \& D{\'e}moulin, P.\ 2005, Advances in Space Research, 35, 2172 Dasso, S., Mandrini, C.~H., D{\'e}moulin, P., Luoni, M.~L., \& Gulisano, A.~M.\ 2005, Advances in Space Research, 35, 711 Dasso, S., Mandrini, C.~H., D{\'e}moulin, P., \& Farrugia, C.~J.\ 2003, Journal of Geophysical Research (Space Physics), 108, 1362