Inductive Local Correlation Tracking or, Getting from One Magnetogram to the Next Goal (MURI grant): Realistically simulate coronal magnetic field in eruptive.

Slides:

Advertisements

Similar presentations

Estimating Surface Flows from HMI Magnetograms Brian Welsch, SSL UC-Berkeley GOAL: Consider techniques available to estimate flows from HMI vector magnetograms,

Advertisements

Using Feature Tracking to Quantify Flux Cancellation Rates Evidence suggests that flux cancellation might play a central role in both formation and eruption.

Time Series of Magnetograms: Evolution, Interpretations, Inferring Flows G. Fisher, Y. Li, B. Welsch.

The Use of Vector Magnetogram Data in MHD Models of the Solar Atmosphere and Prospects for an Assimilative Model George H. Fisher Space Sciences Laboratory.

Energy and Helicity in Emerging Active Regions Yang Liu, Peter Schuck, and HMI vector field data team.

Inductive Flow Estimation for HMI Brian Welsch, Dave Bercik, and George Fisher, SSL UC-Berkeley.

Using HMI to Understand Flux Cancellation by Brian Welsch 1, George Fisher 1, Yan Li 1, and Xudong Sun 2 1 Space Sciences Lab, UC-Berkeley, 2 Stanford.

Can We Determine Electric Fields and Poynting Fluxes from Vector Magnetograms and Doppler Shifts? by George Fisher, Brian Welsch, and Bill Abbett Space.

Photospheric Flows and Solar Flares Brian T. Welsch 1, Yan Li 1, Peter W. Schuck 2, & George H. Fisher 1 1 Space Sciences Lab, UC-Berkeley 2 Naval Research.

SHINE Campaign Event: 1-2 May 1998 Brian Welsch (& Yan Li) Space Sciences Laboratory, UC Berkeley Introduction: Data, Context, etc. Work: Completed & Ongoing.

Using Photospheric Flows Estimated from Vector Magnetogram Sequences to Drive MHD Simulations B.T. Welsch, G.H. Fisher, W.P. Abbett, D.J. Bercik, Space.

1 A New Technique for Deriving Electric Fields from Sequences of Vector Magnetograms George H. Fisher Brian T. Welsch William P. Abbett David J. Bercik.

Reducing the Divergence of Optimization-Generated Magnetic Fields J.M. McTiernan, B.T. Welsch, G.H. Fisher, D.J. Bercik, W.P. Abbett Space Sciences Lab.

Update: Incorporating Vector Magnetograms into Dynamic Models of the Solar Atmosphere CISM-AG Meeting: March 2006 Bill Abbett, Brian Welsch, George Fisher.

HMI, Photospheric Flows and ILCT Brian Welsch, George Fisher, Yan Li, & the UCB/SSL MURI & CISM Teams HMI Team Mtg., 2006M3: Mag Data Products Correlation.

Local Data-driven MHD Simulations of Active Regions W.P. Abbett MURI 8210 Workshop Mar 2004.

Estimating Electric Fields from Sequences of Vector Magnetograms George H. Fisher, Brian T. Welsch, William P. Abbett, and David J. Bercik University of.

HMI & Photospheric Flows 1.Review of methods to determine surface plasma flow; 2.Comparisons between methods; 3.Data requirements; 4.Necessary computational.

HMI – Synoptic Data Sets HMI Team Meeting Jan. 26, 2005 Stanford, CA.

Free Magnetic Energy: Crude Estimates by Brian Welsch, Space Sciences Lab, UC-Berkeley.

MSU Team: R. C. Canfield, D. W. Longcope, P. C. H. Martens, S. Régnier Evolution on the photosphere: magnetic and velocity fields 3D coronal magnetic fields.

1 SDO/HMI Products From Vector Magnetograms Yang Liu – Stanford University

ILCT-Derived Flows are Consistent with Induction Eqn’s Normal Component. Directly measured Derived by ILCT.

Estimating Electric Fields from Vector Magnetogram Sequences G. H. Fisher, B. T. Welsch, W. P. Abbett, D. J. Bercik University of California, Berkeley.

Electric and Velocity Field Determination in the Solar Atmosphere George H. Fisher, University of California, Berkeley Collaborators: Brian Welsch (UCB),

Free Energies via Velocity Estimates B.T. Welsch & G.H. Fisher, Space Sciences Lab, UC Berkeley.

Incorporating Vector Magnetic Field Measurements into MHD models of the Solar Atmosphere W.P. Abbett Space Sciences Laboratory, UC Berkeley and B.T. Welsch,

Determining flows from magnetic field evolution An outline of the approach we’ve adopted at UCB (Welsch, Fisher, Abbett, Regnier)

UCB-SSL Progress Report for the Joint CCHM/CWMM Workshop W.P. Abbett, G.H. Fisher, and B.T. Welsch.

Understanding the Connection Between Magnetic Fields in the Solar Interior and the Solar Corona George H. Fisher Space Sciences Laboratory UC Berkeley.

Finding Photospheric Flows with I+LCT or,“Everything you always wanted to know about velocity at the photosphere, but were afraid to ask.” B. T. Welsch,

Summary of workshop on AR May One of the MURI candidate active regions selected for detailed study and modeling.

SSL (UC Berkeley): Prospective Codes to Transfer to the CCMC Developers: W.P. Abbett, D.J. Bercik, G.H. Fisher, B.T. Welsch, and Y. Fan (HAO/NCAR)

How are photospheric flows related to solar flares? Brian T. Welsch 1, Yan Li 1, Peter W. Schuck 2, & George H. Fisher 1 1 SSL, UC-Berkeley 2 NASA-GSFC.

LCT Active Region Survey: Preliminary Results We proposed to calculate LCT flows (Li et al. 2004, Welsch et al., 2004) in N > 30 ARs, some of which produced.

Magnetogram Evolution Near Polarity Inversion Lines Brian Welsch and Yan Li Space Sciences Lab, UC-Berkeley, 7 Gauss Way, Berkeley, CA , USA.

Measuring, Understanding, and Using Flows and Electric Fields in the Solar Atmosphere to Improve Space Weather Prediction George H. Fisher Space Sciences.

The May 1,1998 and May 12, 1997 MURI events George H. Fisher UC Berkeley.

Flows in NOAA AR 8210: An overview of MURI progress to thru Feb.’04 Modelers prescribe fields and flows (B, v) to drive eruptions in MHD simulations MURI.

Tests and Comparisons of Photospheric Velocity Estimation Techniques Brian Welsch, George Fisher, Bill Abbett, & Yan Li Space Sciences Laboratory, UC-Berkeley.

M1-H2: Magnetic Activity Science Goals and Approaches DRAFT! Chair(s): Abbett/Hoeksema/Komm.

Using HMI to Understand Flux Cancellation by Brian Welsch 1, George Fisher 1, Yan Li 1, and Xudong Sun 2 1 Space Sciences Lab, UC-Berkeley, 2 Stanford.

On the Origin of Strong Gradients in Photospheric Magnetic Fields Brian Welsch and Yan Li Space Sciences Lab, UC-Berkeley, 7 Gauss Way, Berkeley, CA ,

Surface Flows From Magnetograms Brian Welsch, George Fisher, Bill Abbett, & Yan Li Space Sciences Laboratory, UC-Berkeley Marc DeRosa Lockheed-Martin Advanced.

Flows and the Photospheric Magnetic Field Dynamics at Interior – Corona Interface Brian Welsch, George Fisher, Yan Li, & the UCB/SSL MURI & CISM Teams.

Data-Driven Simulations of AR8210 W.P. Abbett Space Sciences Laboratory, UC Berkeley SHINE Workshop 2004.

Understanding the Connection Between Magnetic Fields in the Solar Interior and Magnetic Activity in the Corona W.P. Abbett and G.H. Fisher, B.T. Welsch,

The Use of Vector Magnetogram Data in MHD Models of the Solar Atmosphere and Prospects for an Assimilative Model George H. Fisher Space Sciences Laboratory.

Study of magnetic helicity in solar active regions: For a better understanding of solar flares Sung-Hong Park Center for Solar-Terrestrial Research New.

Using Photospheric Flows Estimated from Vector Magnetogram Sequences to Drive MHD Simulations B.T. Welsch, G.H. Fisher, W.P. Abbett, D.J. Bercik, Space.

Surface Flows From Magnetograms Brian Welsch, George Fisher, Bill Abbett, & Yan Li Space Sciences Laboratory, UC-Berkeley M.K. Georgoulis Applied Physics.

The Effect of Sub-surface Fields on the Dynamic Evolution of a Model Corona Goals :  To predict the onset of a CME based upon reliable measurements of.

Active Region Flux Transport Observational Techniques, Results, & Implications B. T. Welsch G. H. Fisher

1 A New Technique for Deriving Electric Fields from Sequences of Vector Magnetograms George H. Fisher Brian T. Welsch William P. Abbett David J. Bercik.

The Use of Vector Magnetogram Data in MHD Models of the Solar Atmosphere and Prospects for an Assimilative Model George H. Fisher Space Sciences Laboratory.

B. T. Welsch Space Sciences Lab, Univ. of California, Berkeley, CA J. M. McTiernan Space Sciences.

Using Simulations to Test Methods for Measuring Photospheric Velocity Fields W. P. Abbett, B. T. Welsch, & G. H. Fisher W. P. Abbett, B. T. Welsch, & G.

Finding the Flow Field Need flow information! –ideal evolution of coronal B(x,y,z,t) determined entirely by B(x,y,z,0) and v(x,y,0) – get v wrong and get.

UCB MURI Team Introduction An overview of ongoing work to understand a well observed, eruptive active region, along with closely related studies…..

2002 May 1MURI VMG mini-workshop1` Solar MURI Vector Magnetogram Mini-Workshop Using Vector Magnetograms in Theoretical Models: Plan of Action.

Summary of UCB MURI workshop on vector magnetograms Have picked 2 observed events for targeted study and modeling: AR8210 (May 1, 1998), and AR8038 (May.

The May 1997 and May 1998 MURI events George H. Fisher UC Berkeley.

Multiheight Analysis of Asymmetric Stokes Profiles in a Solar Active Region Na Deng Post-Doctoral Researcher at California State University Northridge.

New Coupled Models of Emerging Magnetic Flux in Active Regions W. P. Abbett, S. A. Ledvina, and G.H. Fisher.

The Physical Significance of Time-Averaged Doppler Shifts Along Magnetic Polarity Inversion Lines (PILs) Brian Welsch Space Sciences Laboratory, UC-Berkeley.

Photospheric Flows & Flare Forecasting tentative plans for Welsch & Kazachenko.

Nonlinear force-free coronal magnetic field extrapolation scheme for solar active regions Han He, Huaning Wang, Yihua Yan National Astronomical Observatories,

Is there any relationship between photospheric flows & flares? Coupling between magnetic fields in the solar photosphere and corona implies that flows.

Magnetic Helicity and Solar Eruptions Alexander Nindos Section of Astrogeophysics Physics Department University of Ioannina Ioannina GR Greece.

Abstract We simulate the twisting of an initially potential coronal flux tube by photospheric vortex motions. The flux tube starts to evolve slowly(quasi-statically)

Presentation transcript:

Inductive Local Correlation Tracking or, Getting from One Magnetogram to the Next Goal (MURI grant): Realistically simulate coronal magnetic field in eruptive events. New Idea: Evolve boundary of MHD code consistently with magnetograms. Question: How can one derive a velocity from a time series of magnetograms? Brian Welsch, Bill Abbett, and George Fisher, Space Sciences Lab, UC-Berkeley

Outline 1.How does the field in magnetograms evolve? 2.How can we derive flows consistent with both this evolution and MHD? 3.How do we use these flows?

An example of magnetic evolution in an active region NOAA AR 8210, May – 1 day of evolution seen by MDI

Local Correlation Tracking, Fourier-style Central idea of LCT schema: find proper motions of features in a pair of successive images are by maximizing a cross-correlation function (or minimizing an error function) between sub-regions of the images. The concept is generally attributed to November & Simon (1988). Useful with G-band filtergrams, H  images, or magnetograms. The FLCT method (which we developed) is similar. For each pixel, we: –mask each image with a Gaussian, of width , centered at that pixel; –crop the resulting images, keeping only signficant regions; –compute the cross-correlation function between the two cropped images, using standard Fast Fourier Transform (FFT) techniques; –use cubic-convolution interpolation to find the shifts in x and y that maximize the cross-correlation function to one of two precisions (chosen by the user), either 0.1 or 0.02 pixel; and –use the shifts in x and y and  t between images to find the intensity features' apparent motion along the solar surface.

Example of FLCT applied to NOAA AR 8210 (May )

The Demoulin & Berger (2003) Interpretation of LCT Apparent horizontal motion, U LCT, is from combination of horizontal motions and vertical motions acting on non-vertical fields.

The Ideal MHD Induction Equation How can we ensure that LCT-determined velocities are physically consistent with the magnetic induction equation? Only the z-component of the induction equation contains no unobservable vertical derivatives: Now, substitute in the Demoulin & Berger hypothesis The ideal MHD induction equation simplifies to this form:

I+LCT: Use LCT to constrain solutions of the induction equation Solve for ,  with 2D divergence and 2D curl (z-comp), and the approximation that U=U LCT : Let Note that if only B z (or an approximation to it, B LOS ) is known, we can still solve for ,  !

Apply ILCT to IVM vector magnetogram data for AR 8210 Vector magnetic field data enables us to find 3-D flow field from ILCT via the equations shown on slide 5. Transverse flows are shown as arrows, up/down flows shown as blue/red contours.

Flows Consistent with Induction Equation!

We have v(x,y,0;t) --- now put it all together...

Bill Abbett has driven an MHD code with v(x,y)!

Conclusions From a time series of vector magnetograms, we’ve derived three-component, photospheric flows that are quantitatively consistent with the induction equation’s z-component. Qualitatively, the flows appear consistent with the observed field evolution. We’re using these flows to drive MHD simulations – please stay tuned!

ILCT Flows are Only Consistent with Induction Eqn’s Normal Component! Directly measured Derived by ILCT

Directly measured ???? ???? What about other components?Derived by ILCT From NLFFF Extrapolation/ Prev. Time Step at photosphere, z = 0above photosphere, z > 0

Incorporate Vertical Gradients with a Boundary Code!

Directly measured Calculated by Boundary Code What about other components?Derived by ILCT From NLFFF Extrapolation/ Prev. Time Step at photosphere, z = 0above photosphere, z > 0

Induction Equation’s Components

Driving Simulations from LOS Data, p.1 1.Start with a vector magnetogram. 2.Derive ,  that will move system from vector data to initial LOS data. 3.Derive ,  to move system from one LOS magnetogram to the next. 4.Evolve code, using B and ,  at each step to find v(x,y) via:

Driving Simulations from LOS Data, p.2

Driving Simulations from LOS Data, p.3

Driving Simulations from LOS Data, p.4

Driving Simulations from LOS Data, p.5

Driving Simulations from LOS Data, p.6

Driving Simulations from LOS Data, p.7