Solar wind speed variations during an activity cycle

Transcription

1 Solar wind speed variations during an activity cycle Rui PINTO and collaborators: Sacha Brun (CEA Saclay, AIM/SAp), Laurène Jouve (IRAP, Toulouse), Sean Matt (U. Exeter) Roland Grappin (LPP, École Polytechnique), Yi-Ming Wang (NRL), Nicole Vilmer (LESIA) Andrea Verdini (ROB, Brussels), Marco Velli (JPL & Firenze) Rui PINTO ESEP 3, Orléans March 24

2 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Context The solar wind and the solar cycle McComas et al. (23) Solar minimum Dipolar large-scale magnetic field, few AR Fast wind / slow wind separation Rui PINTO (rui.pinto@obspm.fr) Solar maximum Multipolar large-scale magnetic field, many AR Fast wind / slow wind mixed together ESEP 3, Orle ans March 24 2

3 Context Sun Earth connections Interactions between solar dynamo corona and wind Slow (cycle-long) variations of the wind properties Explain / predict solar wind speeds from surface diagnostics Solar Orbiter Impulsive phenomena coronal transients (magnetic flux-emergence, eruptions) Global topological variations: triggering and propagation of perturations Mass and momentum loss rates vary during the cycle Other stars (Cohen, et al., 29; Jardine, et al., 23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 3

4 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface. Slow cyclic variations Rui PINTO ESEP 3, Orléans March 24 4

5 Models STELEM (kinematic dynamo) Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface DIP (corona, solar wind) dw_b; (u_//)/cs; nt= Convective zone, tachocline Meridional circulation, diff. rotation Surface fields ( butterfly diagram ) (Jouve and Brun, 27) Isothermal corona and wind Self-consistent time-dependent mass flux at the boundaries (Grappin et al., 2; Pinto et al., 2) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 5

6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Magnetic topology during the activity cycle 4 4 Dynamo solar wind; solar cycle (Pinto et al., 2) Influence of the solar dynamo in the global properties of the solar wind.5 Coronal field topology and wind speed maps t =. yr t 2 = 3.3 yr Streamer migration meridional circulation Surface corona connections 2 2. (out-of ecliptic probes: Ulysses, Solar Orbiter) t 3 = 3.8 yr t 4 =. yr Wind speed, magnetic field lines, polarity. 4 instants of the cycle, northern hemisphere, r = 4 R Constraints for stellar evolution: Modulation of the mass and momentum loss rates Codes: STELEM (dynamo), DIP (wind) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 6

7 Wind speed during the cycle Wind speed; time-latitude diagrams SIMULATION Ur [km/s]; r = 5 R_sun t 6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface 45. Nobeyama radio IPS map (Shibasaki, K.; priv. comm.) t time [yr] 6 4 t 5 t t 4 3 t t latitude 5 latitude ULYSSES (Wang and Sheeley, 26) t latitude (see also: Manoharan, 22; Tokumaru et al., 2) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 7

8 Wind speed during the cycle Wind speed; time-latitude diagrams t 8 SIMULATION Ur [km/s]; r = 5 R_sun t 6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Wind speed and flux-tube expansion factor WIND data f ss - B (998-22) time [yr] t 5 t t 4 3 t log (f ss) t t latitude 5 latitude ULYSSES (Wang and Sheeley, 26) v p (km s - ) log B (G) v p - B (998-22) latitude Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March

9 Wind speed during the cycle Wind speed; time-latitude diagrams SIMULATION Ur [km/s]; r = 5 R_sun t 6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface 45. Wind speed and flux-tube expansion factor SIMULATION (at solar minimum) t time [yr] t 5 t t 4 3 t A /A (R /R ) 2 t latitude 5 latitude ULYSSES (Wang and Sheeley, 26) B [G] t Orange: fast wind; Blue: slow wind Strongly expanding flux-tubes slow wind cf. WSA semi-empirical relation (used as predictive tool for space weather) (Arge and Pizzo, 2; Wang and Sheeley, 99) latitude Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 7

10 Wind speed during the cycle Wind speed; time-latitude diagrams SIMULATION Ur [km/s]; r = 5 R_sun t 6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface 45. Wind speed and flux-tube expansion factor SIMULATION (at solar maximum) t time [yr] t 5 t t 4 3 t A /A (R /R ) 2 t latitude 5 latitude ULYSSES (Wang and Sheeley, 26) B [G] t Orange: fast wind; Blue: slow wind Strongly expanding flux-tubes slow wind cf. WSA semi-empirical relation (used as predictive tool for space weather) (Arge and Pizzo, 2; Wang and Sheeley, 99) latitude Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 7

11 Wind speed during the cycle Wind speed; time-latitude diagrams SIMULATION Ur [km/s]; r = 5 R_sun t 6 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface 45. Wind speed and flux-tube expansion factor SIMULATION (all the cycle) t time [yr] t 5 t t 4 3 t A /A (R /R ) 2 t latitude 5 latitude ULYSSES (Wang and Sheeley, 26) B [G] t Orange: fast wind; Blue: slow wind Strongly expanding flux-tubes slow wind cf. WSA semi-empirical relation (used as predictive tool for space weather) (Arge and Pizzo, 2; Wang and Sheeley, 99) latitude Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 7

12 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfve n surface Coronal rotation t = yr t4 = 3.8 yr blue: wind speed vr /cs ; orange:rotation rate Ω Surface differential rotation profile: Ω (θ) = Ωa + Ωb sin2 θ + Ωc sin4 θ Parametrising the effects of the chromospheric stratification in the angular momentum transport (Snodgrass and Ulrich, 99) a= +, = photosphere C A C corona A (Grappin et al., 28; Pinto et al., 23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 8

13 Coronal rotation Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Open-field regions: Parker Spiral Closed-field regions: rigid rotation, opposing to foot-point shearing. r =, 2.5, 7, 5 R Pinto, Verdini, et al (22) t = yr blue: wind speed v r /c s; orange:rotation rate Ω Surface differential rotation profile: Ω (θ) = Ω a + Ω b sin 2 θ + Ω c sin 4 θ (Snodgrass and Ulrich, 99) Parametrising the effects of the chromospheric stratification in the angular momentum transport a = ɛ +ɛ, ɛ = C photosphere A C corona A (Grappin et al., 28; Pinto et al., 23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 8

14 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Coronal rotation Solar maximum: less uniform coronal rotation pattern. Stronger latitudinal shear between streamers and coronal holes. r =, 2.5, 7, 5 R Pinto, Verdini, et al (22) t 4 = 3.8 yr blue: wind speed v r /c s; orange:rotation rate Ω Surface differential rotation profile: Ω (θ) = Ω a + Ω b sin 2 θ + Ω c sin 4 θ (Snodgrass and Ulrich, 99) Parametrising the effects of the chromospheric stratification in the angular momentum transport a = ɛ +ɛ, ɛ = C photosphere A C corona A (Grappin et al., 28; Pinto et al., 23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 8

15 Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Mass loss rate Ṁ [M /yr] SIMULATION ACE, WIND (Cranmer, 28; Wang, 998) 7-4 d/dt M [M sun /yr] time [yr] time ( years, cycle) ) ) max (Ṁ / min (Ṁ.6 Ṁ M /yr Ṁ anti-correlates with V wind geometrical effects dominate! time (22 years, 2 cycles) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 9

16 Alfvén surface Models Magnetic topology Wind speed Coronal rotation Mass loss rate Alfvén surface Alfvén surface Average Alfvén radius r A < R alfven > [R sun ] t =. yr t 2 = 3.3 yr 5 5 Angular momentum flux [cgs] Consequences: time [yr] r A = 2 9 R Solar 6. wind 7 properties below/above Alfvén surface (fluctuations, turbulence; Solar Probe+) 4. 7 (Verdini, 2. 7 Grappin, Pinto, and Velli, 22) Star-planet interaction (magnetic coupling) time [yr] Efficiency of ang. momentum transport r A 2 Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24

17 Dynamo and twisted flux-ropes Surface Global topology 2. Dynamos with flux-emergence Rui PINTO ESEP 3, Orléans March 24

18 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Dynamo and twisted flux-ropes Surface Global topology Background dynamo field and twisted flux-ropes Left: full domain. % Right: zoom over the mid-latitudes. Green/red tubes: magnetic field-lines; Yellow/blue volumes : upflows/downflows. Latitude 3 N (Pinto & Brun, 23) Global dynamo field + flux-ropes Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 2

19 Surface magnetic field Dynamo and twisted flux-ropes Surface Global topology positive polarity, right-handed flux-rope negative polarity, right-handed flux-rope t = 2 d t = 5 d t = 25 d t = 45 d Flux-emergence surface B-field variations, Surface flows precede and accompany the flux-emergence episode. Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 3

20 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Dynamo and twisted flux-ropes Surface Global topology Global topology Coronal magnetic field dynamo background only, no flux-rope added Emerged flux : large-scale perturbations to the coronal field. Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 4

21 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Dynamo and twisted flux-ropes Surface Global topology Global topology Coronal magnetic field dynamo background + flux-rope Emerged flux : large-scale perturbations to the coronal field. Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 4

22 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Flares in kink-unstable coronal flux-ropes Flares in kink-unstable coronal flux-ropes Magnetic twist (TRACE 7) Simulated flux-rope synthetic continuum emission at 5 kev Hot coronal loops (HiC + AIA) Instrument: RHESSI perihelion aphelion Pixel size: 5 Mm Pinto, Vilmer, and Brun (24) Curved loops + stratification (Gordovskyy, Pinto, et al, in prep.) (Srivastava et al., 2) Testa, et. al (23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 5

23 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Conclusions Conclusions Dynamo solar wind relations Robust numerical method, well adapted to long time-scale studies. Variations of global magnetic topology have a major effect on the wind properties. Flux-emergence surface motions + magnetic flux Perspectives Time-dependent coupling (coronal response to impulsive events) Solar data (magnetograms, IPS radio, data-assimilation) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orle ans March 24 6

24 References I C. N. Arge and V. J. Pizzo. Improvement in the prediction of solar wind conditions using near-real time solar magnetic field updates. Journal of Geophysical Research, 5:465 48, May 2. URL S. R. Cranmer. Winds of main-sequence stars: Observational limits and a path to theoretical prediction. volume 384, page 37, April 28. URL R. Grappin, J. Léorat, and A. Buttighoffer. Alfvén wave propagation in the high solar corona. Astronomy and Astrophysics, 362: , October 2. URL R. Grappin, G. Aulanier, and R. Pinto. The MHD coupling between coronal dynamics and photospheric motions. Astronomy and Astrophysics, 49: , October 28. URL L. Jouve and A. S. Brun. On the role of meridional flows in flux transport dynamo models. Astronomy and Astrophysics, 474: , October 27. URL P. K. Manoharan. Three-dimensional evolution of solar wind during solar cycles The Astrophysical Journal, 75:28, June 22. ISSN 4-637X. doi:.88/4-637x/75/2/28;. URL D. J. McComas, H. A. Elliott, N. A. Schwadron, J. T. Gosling, R. M. Skoug, and B. E. Goldstein. The three-dimensional solar wind around solar maximum. Geophysical Research Letters, 3:24, May 23. URL A. Mignone, G. Bodo, S. Massaglia, T. Matsakos, O. Tesileanu, C. Zanni, and A. Ferrari. PLUTO: a numerical code for computational astrophysics. The Astrophysical Journal Supplement Series, 7: , May 27. URL A. Mignone, C. Zanni, P. Tzeferacos, B. van Straalen, P. Colella, and G. Bodo. The PLUTO code for adaptive mesh computations in astrophysical fluid dynamics. The Astrophysical Journal Supplement Series, 98:7, January 22. ISSN doi:.88/67-49/98//7;. URL R. Pinto, R. Grappin, and J. Leorat. Coronal inflows and giant polar plumes. In Twelfth International Solar Wind Conference, volume 26, pages 8 83, Saint-Malo, (France), March 2. AIP. doi:.63/ URL Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 7

25 References II R. F. Pinto, R. Grappin, M. Velli, and A. Verdini. Coupling the solar surface and the corona: Coronal rotation, alfvén wave-driven polar plumes. volume 539, pages 58 6, June 23. ISBN X. doi:.63/.48989;. URL R. F. Pinto, N. Vilmer, and A. S. Brun. Soft x-ray emission in flaring coronal loops. ArXiv e-prints, 4:96, January 24. URL Herschel B. Snodgrass and Roger K. Ulrich. Rotation of doppler features in the solar photosphere. The Astrophysical Journal, 35: 39, March 99. ISSN 4-637X, doi:.86/ URL A. K. Srivastava, T. V. Zaqarashvili, Pankaj Kumar, and M. L. Khodachenko. Observation of kink instability during small b5. solar flare on 27 june 4. The Astrophysical Journal, 75: , May 2. ISSN 4-637X. doi:.88/4-637x/75//292;. URL Munetoshi Tokumaru, Masayoshi Kojima, and Ken ichi Fujiki. Solar cycle evolution of the solar wind speed distribution from 985 to 28. Journal of Geophysical Research (Space Physics), 5:42, April 2. URL Andrea Verdini, Roland Grappin, Rui Pinto, and Marco Velli. On the origin of the /f spectrum in the solar wind magnetic field. The Astrophysical Journal Letters, 75:L33, May 22. URL Y.-M. Wang. Cyclic magnetic variations of the sun. volume 54, page 3, 998. URL Y.-M. Wang and N. R. Sheeley. Solar wind speed and coronal flux-tube expansion. Astrophysical Journal, 355: , June 99. URL Y.-M. Wang and N. R. Sheeley. Sources of the solar wind at ulysses during Astrophysical Journal, 653:78 78, December 26. URL Rui PINTO ESEP 3, Orléans March 24 8

26 . Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus Bonus Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients dw_b6c; u_pol /cs; nt= 29. ; TUBE B Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 9

27 Bonus Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients dm/dt [num units] t [yr] dj/dt [num units] t [yr] Psi/Psi t [yr] <r A > [R sun ] t [yr] Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 2

28 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Bonus t =. yr full domain Y [R sun ] A_/A_ B X [R sun ] 3 t =. yr detail theta theta Y [R sun ] A_/A_ V r X [R sun ] B theta Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 2

29 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Bonus t = 2.8 yr full domain Y [R sun ] A_/A_ B X [R sun ] 3 t = 2.8 yr detail theta theta Y [R sun ] A_/A_ V r X [R sun ] B theta Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 22

30 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Bonus t = 6.6 yr full domain Y [R sun ] A_/A_ B X [R sun ] 3 t = 6.6 yr detail theta theta Y [R sun ] A_/A_ V r X [R sun ] B theta Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 23

31 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Coronal rotation Partial chromospheric reflection; partial foot-point leakage δl + a = ( + a) f (t) aδl a, a = ɛ + ɛ, ɛ = C photosphere A C corona A δl ± a : forces and torques applied at the surface from above and below (cf. Pinto, Verdini, et al., 22). ɛ = fully-transparent ɛ line-tied approximation. Valid for δt τ A. (Grappin, Aulanier, Pinto, 28) ɛ =. canonic value. Why? Consistency of mass and momentum fluxes at the boundary Sustain the coronal rotation against the solar wind magnetic breaking torque, while still allowing for the necessary amount of footpoint leakage (coronal stress build-up and release, cf. Jardine et. al 23). Allow for time-dependent surface perturbations Avoid the chromosphere ( slow perturbations ) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 24

32 8. 7 Introduction Dynamo wind Flux emergence Flares Conclusion References Bonus 6. 7 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Angular momentu 4. Wind braking 7 torque 2. 7 Spin-down time-scale 2 4 δt sd 6= J / 8 J time [yr] Spin-down timescale [yr] time [yr] Very strong spin-down torque modulation! momentum advection (braking torque) J B rv ϕ rb p ϕ dθ ρv p magnetic tension (counter-torque) fast B decay at the maximum dominates <r a > / R sun Scaling laws: B r A α (Matt & Pudritz, 28; Kawaler, 28) Φ open r A α (Reville, et al, in prep.) <r a > / R sun <r a > / R sun B 2 R 2 sun / M dot Varying B (dipole) B 2 R 2 sun / M dot t 2 t 3 t 4 t 5 Cycle t 6 t B 2 R 2 sun / M dot Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 25

33 Flux-tube expansion Coronal rotation Spin-down Flux emergence, coronal transients Flux emergence, coronal transients δρ V r / V r r.m.s. φ Influence on the corona 3D MHD global model, convective zone and chromosphere; ASH code (Pinto & Brun, 2) Sub-surface motions and flux-emergence. Mécanismes de transport d impulsion? Complex dynamics + different regimes (Pinto & Brun, 23) Rui PINTO (rui.pinto@obspm.fr) ESEP 3, Orléans March 24 26