Time Series of Magnetograms: Evolution, Interpretations, Inferring Flows

G. Fisher, Y. Li, B. Welsch

Discussion Topics

• G. Fisher: LCT, ILCT

• Y. Li: LCT applied to data, masking (thr), convergence/cancellation/rotation

1. 12 May 1997

2. 25-26 Sept. 1996

3. 28-29 Oct. 2003

• B. Welsch: reality check – FGE data

Flare Genesis Experiment• Balloon-borne (Antarctic) observations of

NOAA 8844, 25 Jan 2000• 54 vector magnetograms, ~2.3/5.3 min. per• hi-res: 18” pixels (130.5 km), ~520 x 520 pix

• LCT at ti differenced over ti +/-10, for

t ~85 min.• Doppler maps, too! (No info. on method.)• Tracking of white light images underway…

Test velocity inversion methods…

• Data movie

• Doppler movie

• LCT

• ILCT

• MEF

FGE Data Movie

(BACK)

FGE Doppler Map

(BACK)

LCT Results

MEF Horiz(LCT)

MEF V_z

(DOPPLER)

ILCT Horiz(LCT)

ILCT V_z(DOPPLER)

ADC V_z(DOPPLER)

• Apparent horizontal motion can be either true horizontal motion, or vertical motion of a tilted field geometry.

zzzzz

vB - vB uBvB

B - v u

ILCT: Reinterpret LCT, a la Demoulin & Berger (2003)

ILCT, cont’d: Find

• Similar to MEF, use scalar potentials:

• As w/MEF: indn eqn. fixes ; ass’d.

• Instead of minimizing ‘energy’ to find , ILCT uses LCT to constrain :

)uB( 2LCTz

)z (vB-BvuB- zzz

0Bv