Understanding Magnetic Eruptions on the Sun and their Interplanetary Consequences

1. Understanding Magnetic Eruptions on the Sun and their Interplanetary Consequences A Solar and Heliospheric Research grant funded by the DoD MURI program George H. Fisher, PI Space Sciences Laboratory University of California, Berkeley

2. Goal Develop a state-of-the-art, observationally tested 3-D numerical modeling system for predicting magnetic eruptions on the Sun and the propagation of Coronal Mass Ejections (CMEs).

3. Motivation The Sun drives the magnetic eruptions that initiate violent space weather events. The mechanisms that trigger and drive these eruptions are the least understood aspects of space weather. A better physical understanding of how magnetic eruptions occur on the Sun and how the disturbances propagate through the Heliosphere will surely lead to more accurate and longer range forecasts.

4. Approach • Perform in-depth, coordinated space and ground based observations of magnetic eruptions and Coronal Mass Ejection (CME) propagation • Understand the physics of how magnetic eruptions are triggered and powered • Develop numerical models for the initiation and propagation of CMEs and the acceleration of Solar Energetic Particles (SEPs) • Couple together the observationally tested models of the Sun and Heliosphere

5. Institutions of Solar Multidisciplinary University Research Initiative Team • UC Berkeley • Big Bear Solar Observatory (NJIT) • Drexel University • Montana State University • Stanford University • UC San Diego • University of Colorado • University of Hawaii • University of New Hampshire

6. Overview of Solar MURI 2. Effects of Large Scale Field and Solar Cycle Evolution: Hoeksema, Scherrer, & Zhao (Stanford), Ledvina & Luhmann (UCB), Martens (MSU), Goode, Wang & Gallagher (BBSO) 1. Active Region Emergence: Fisher & Abbett (UCB), LaBonte, Jing Li, & Mickey (UH), Canfield & Regnier (MSU), Liu (Stanford), Gallagher,Moon, Wang & Goode (BBSO) 3. Inner Corona: Forbes (UNH), MacNeice (Drexel), Abbett, Ledvina, Luhmann & Fisher (UCB), Kuhn & H. Lin (UH), Canfield & Longcope (MSU), Hoeksema, Scherrer & Zhao (Stanford) 4. Outer Corona, Solar Wind, SEPs: Odstrcil (CU), Jackson, Dunn & Hick (UCSD), MacNeice (Drexel), Luhmann & R. Lin (UCB), Lee (UNH) 5. Geoeffects: Luhmann & R. Lin (UCB), Odstrcil (CU), Hoeksema & Zhao (Stanford)

7. Website for Solar MURI Project: http://solarmuri.ssl.berkeley.edu

8. Accomplishments During 1st year • Solar and Heliospheric MHD codes now include adaptive mesh refinement, necessary for a large dynamic range of spatial scales • CME observational data have been collected and organized, and is accessible from a single web page. Test cases for numerical modeling have been identified. • New observational capabilities are being created • Community-based workshops have been organized to address the most pressing research problems.

9. Coupled Models of Emerging Magnetic Flux in Active Regions: an illustration of AMR with Paramesh in “ZeusAMR” Use ANMHD to model the rise of a modestly twisted active region through the solar convection zone Use result from this simulation to drive a fully compressible version of ZeusAMR, a merge of Zeus-3d with Paramesh (Abbett, Ledvina, & MacNeice)

10. The above figure shows a volume rendering of |B| in the ANMHD domain, which spans roughly 5 pressure scale heights.

11. A snapshot of a Zeus3D corona being driven by the emerging Omega loop of the previous slide. Magnetic fieldlines are traced in blue, and the vertical component of the magnetic field along the Zeus-3D lower boundary is shown as a greyscale image: the light areas represent regions of positive polarity, and dark areas represent negative polarity. Here, no adaptive mesh is used, and as a result, only a small fraction of the emerging flux can be modeled.

12. The figures above show a snapshot in time (from different vantage points) of the initially field-free ZeusAMR corona responding to this emerging Omega-loop. Note that the mesh has refined in the neighborhood of the active region and has de-refined elsewhere in response to a refinement criterion based on a normalized second derivative of the field strength.

13. Here, we show a close-up of the magnetic fieldlines in the low-corona just above the emerging bipole; the shaded contour along the vertical slice is the upward velocity of the plasma. In this figure, both the mesh and the block boundaries are shown. On a parallel computer, ZeusAMR allows for each block to be calculated on a separate processor. This scales well on parallel supercomputers, since each block (regardless of its physical dimensions) has the same number of cells (in this case, 8x8x8).

14. Accomplishments During 1st year • Solar and Heliospheric MHD codes now include adaptive mesh refinement, necessary for a large dynamic range of spatial scales • CME observational data have been collected and organized, and is accessible from a single web page. Test cases for numerical modeling have been identified. • New observational capabilities are being created • Community-based workshops have been organized to address the most pressing research problems.

15. Assembling a database of CME events (Yan Li) http://solarmuri.ssl.berkeley.edu/~yanli/public/htmls/events.html

16. The First MURI Case Study:  May 1 1998 - A Flare and CME from NOAA 8210 • Photosphere: Continuum images of AR8210 show sunspot umbrae of opposite polarities within a single penubra. This configuration,known as a “d-spot” configuration, is known to be associated with major flares. • Flux emergence and motions of sunspots are observed (see Barry Labonte's movies at http://www.solar.ifa.hawaii.edu/People/labonte/ivmflare/ivmmovie1/ivm_19980501.html . • A large number of vector magnetograms are available both before and after the flare and CME; • A map of the Full Sun longitudinal magnetic field is provided by the MDI/SOHO magnetograph.

17. Coronal Features of AR 8210 • AR8210 is well observed by coronal instruments such as CDS/SOHO, EIT/SOHO, SXT/Yohkoh, LASCO/SOHO • A flare is observed in AR8210 near the disk center on May 1, 1998 • A halo CME (toward the Earth) is associated with the flare of May 1, 1998

18. Accomplishments During 1st year • Solar and Heliospheric MHD codes now include adaptive mesh refinement, necessary for a large dynamic range of spatial scales • CME observational data have been collected and organized, and is accessible from a single web page. Test cases for numerical modeling have been identified. • New observational capabilities are being created • Community-based workshops have been organized to address the most pressing research problems.

19. Coronal magnetic fields The future for space weather prediction depends on direct measurements of coronal magnetic fields. The infrared FeXIII line will allow this. Experimental determination of coronal field strength from Zeeman splitting has been obtained. Shortly the Haleakala observatory will provide these measurements for routine diagnostic use. This EUV image shows contours of coronal Green-line emission measured from the ground. The small box labeled A is a region where infrared Zeeman field observations were obtained (below) The infrared spectrum near 1000nm directly reveals the coronal magnetic field This line profile is one of the first measurements of a 30G coronal magnetic field

20. Magnetic field inputs to space weather activity The Haleakala observatory is the worlds highest elevation solar observatory. It sits above 20% of the atmosphere and provides unrivaled infrared observing conditions. On a daily basis the high altitude Mees observatory on Haleakala provides the solar vector magnetic field measurements required to model and predict the evolving interplanetary field configuration. This image shows the vector field from a bipolar Active region (number 1731) on February 21, 2002

21. Active Region Monitor(ARM;www.bbso.njit.edu/arm) • A web-based summary of the latest solar activity (every hour update) • BBSO H-alpha, SOHO EIT, MDI continuum and magnetogram, Yohkoh SXT, GONG magnetograms, GOES X-ray, and SEC event lists etc. • Trace back and after with an active region • Flare Prediction System based on McIntosh magnetic class

22. BBSO H-a Movie(ftp.bbso.njit.edu/pub/archive) • - Daily full-disk • - Flaring movie • - Sun online • - Global H-alpha • Network

23. Accomplishments During 1st year • Solar and Heliospheric MHD codes now include adaptive mesh refinement, necessary for a large dynamic range of spatial scales • CME observational data have been collected and organized, and is accessible from a single web page. Test cases for numerical modeling have been identified. • New observational capabilities are being created • Community-based workshops have been organized to address the most pressing research problems.

24. MURI mini-workshops: • Use of synoptic, global scale magnetograms in coronal/heliospheric models (April 15, B. V. Jackson, Boulder) • Using vector magnetogram data in MHD simulation and other theoretical models (April 29, G.H. Fisher & R.C. Canfield, Berkeley) • Well defined numerical experiments for CME eruption mechanisms (May 14-16, T.J. Forbes, Durham NH)

25. Summary • A great deal has been accomplished during the 1st year • Major challenges remain in numerical code development and in the use of solar data to drive numerical simulations