Progress of MHD Simulations for the Interplanetary Propagation of Coronal Mass Ejections

Transcription

1 Progress of MHD Simulations for the Interplanetary Propagation of Coronal Mass Ejections C. Verbeke, J. Pomoell, S. Poedts ISEST workshop, Jeju,

2 Overview Introduction Constraining CME model parameters Interaction with ambient solar wind and CMEs MHD-Simulations Heliospheric modeling ENLIL SUSANOO-CME EUHFORIA Conclusions

3 Introduction

4 Coronal Mass Ejections (CMES) 21 June 2015 event

5 Structure of CMEs: Flux ropes 21 June 2015 event

6 Structure of CMEs: Flux ropes Ying D. Liu et al., 21 June 2015 event IMF Bz prediction is crucial to determine the geo-effectiveness of an event.

7 Eruption mechanisms Break-out model: Sheared arcade Pre-existing flux rope: Flux cancellation (Antiochos et al., 1991) (J.Leake et al., 2010) (T. Amari et al., 2000)

8 Example of flux rope modeling (Xia, C. and Keppens, R., 2016, ApJ, 823, 22)

9 Example of flux rope modeling Credit: S. Hosteaux

10 Flux rope orientation (Bothmer & Schwenn, 1998)

11 Constraining CME model parameters

12 Constraining CME model parameters GCS modeling (Thernisien et al., 2009) StereoCAT (CCMC, NASA GSFC) Credit: C. Scolini

13 Constraining CME model parameters GCS modeling (Thernisien et al., 2009) StereoCAT (CCMC, NASA GSFC) What is the error on those parameters? Credit: C. Scolini

14 CME kinematics team CCMC working team Determining a clearer view on the error of CME kinematics Currently: - Collecting all CME measurements for certain set of events - Starting with study on the spread of the measurements

15 Interactions with ambient solar wind and CMEs

16 Interaction with ambient solar wind - Fast CME: Slowed down by preceding solar wind - Slow CME: pushed forward by following solar wind - Deflection of CME (Zurbuchen and Richardson, 2005)

17 CME-CME interaction Possible halt to flux rope expansion Possible arrival of strong magnetic fields (N. Lugaz et al., 2007)

18 Overview of CME alteration processes Flux rope structure Ambient solar wind Possible reconnection Rotation Deflection Acceleration or deceleration CME-CME interaction

19 Overview of CME alteration processes Flux rope structure Ambient solar wind Possible reconnection Rotation Deflection Acceleration or deceleration Simulations are needed! CME-CME interaction

20 3D MHD- Simulations

21 MHD simulations Several efforts for realistic 3D MHD modeling Our knowledge of CME is not perfect Eruption mechanism? CME parameters? CME models needed to fill in this information consistently

22 Coronal model: AWSoM_R+EEGL - Models from close to sun up to Earth - Possible to include a Gibson- Low flux rope - Uses significant amount of resources è Currently not possible to use for: Forecasting Large parameter studies Source: CCMC website

23 Heliospheric models

24 Heliospheric models Advantage: Skips the coronal region à faster computation à supersonic wind Needs a pre-model to go from the solar surface up to the inner boundary.

25 WSA-ENLIL+Cone model CME modeled as Cone model à Hydrodynamic pulse è NO intrinsic magnetic field

26 SUSANOO-CME Flux rope modeling è pancake shape YinYang grid Time varying inner boundary conditions

27 SUSANOO-CME Flux rope modeling è pancake shape YinYang grid Time varying inner boundary conditions (Oct 2003)

28 EUHFORIA EUropean Heliospheric FORcasting Information Asset NEW heliospheric model Solar 0.1 AU Semi-empirical CMEs 0.1 AU Cone model Inner Heliosphere 0.1 AU à 2 AU Time-dependent 3D MHD 0.1 AU 1 AU 2 AU

29 EUHFORIA Magnetogram Solar wind model Heliosphere model Coronagraph imagery CME model 0.1 AU Observational data Empirical / datadriven models Physics-based model

30 Semi-empirical solar wind model Updated to include distance to coronal hole boundary:

31 Semi-empirical solar wind model

32 Solar wind model run Relaxation of solar wind at start of a run

33 Solar wind model run Operational on daily basis at Royal Observatory Belgium (ROB), Brussels

34 EUHFORIA solar wind calibration Optimize the solar background wind à On-going collaboration with University of Graz and Royal Observatory Belgium à Semi-empirical model!! Comparing simulations of daily synoptic maps with observations From Andrei Zhukov s talk!

35 VSWMC: Virtual Space Weather Modeling Centre

36 VSWMC: Virtual Space Weather Modeling Centre - Repository for data and models - Execute models and link them - Models remotely coupled - Visualization tool can be run parallel - Developer tool

37 Phases of a run with EUHFORIA Magnetogram observation time

38 June 2015 event DONKI CCMC parameters

39 03:03 UT on June 21, 2015 June 2015 event

40 11:02 UT on June 22, 2015 June 2015 event

41 11:02 UT on June 24, 2015 June 2015 event

42 11:03 UT on June 27, 2015 June 2015 event

43 June 2015 event (J. Pomoell, S. Poedts, submitted)

44 Gibson-Low flux rope model Gibson-Low flux rope model (Gibson, Low, 1999) Analytic model with self-similar evolution Stretched spheromak like structure

45 Gibson-Low flux rope model: Parameters CME kinematics Cone model Start time of CME Propagation velocity of CME Latitude of centre of CME source region Longitude of centre of CME source region Half-width of CME Density of CME Temperature of CME Title angle of the CME Helicity of the CME Magnetic field strength parameter Stretching factor Flux rope parameters

46 Flux rope CME Earth orbit CME shock (SEP source) Shock from previous CME

47 June 2015 event: Flux rope

48 June 2015 event: Flux rope Bz cone model Bz flux rope model

49 June 2015 event: Flux rope

50 Advantages Fast computation possible Parametric studies hence possible Study the dynamics of CME interactions

51 Shortcomings and uncertainties CME input parameters à Error from observations? Solar background wind modeling should be improved Starts only at 0.1AU For flux rope: magnetic field parameters?

52 CME arrival and impact team: Aims Evaluate where we stand with CME arrival time and impact prediction Establish metrics agreed upon by the community Provide a benchmark against which future models can be assessed Both science and prediction Online database of model inputs, outputs, and observations Skill scores

53 CME arrival and impact team

54 Conclusions Much work to do à Simulations and models can help us understand Magnetic field inclusion into the CME modeling is needed Our newly-developed model EUHFORIA aims to include this Parametric studies are now needed

55 Thank you for your attention