Solar Cycle 24 Group F

Tuesday 9th Dec

Introduction 14:30 - 16:00

STERLING Earliest phases of solar eruptions

preflare phase & trigger mechanism for filaments as tracer of B field, slow rise -> flare + fast rise

few (12) example event studied. 2 may 2007, TRACE & HINODE, good example.

filaments undergo slow rise (few km/s), then fast. the slow rise is linear then flare at start of fast eruption. could be some signatures of 'breakout'

dimmings - local (near neutral line) or remote (associated with breakout?)

QUESTIONS ARISING: how common is a slow rise? what triggers slow & fast rise phases?

where to go from here? Clearly Hinode and SECCHI 171 2 min cadence? so synoptic data modes are fine for this project?

ATRILL Coronal waves and dimmings

EIT waves map the CME footpoints? Angelos -mixing lateral mass expansion & wave? Atrill - the expansion of CME stops when wave stops.

Explains the brightnenings at the CME legs

WD - Tunnelling of waves into coronal hole?

Dimmings: could be evacuation or cooling also agree with deep core and secondary dimmings

Mass measurements from plasma outflows?

Angelos: No brightenings in 304, so not reconnection? McAteer: reflection and refraction problem?

Attril: does not mean there is no wave, the CME footpoints could cause a wave?

why/how do CD disappear while magnetic connectivity of the CME ejecta to Sun is maintained? recovery can be due to Interchange reconnection.

reconnection rate at same speed as the wave? 0.1 X 0.2 alfven speed - too low?

expansion of cme flanks should correspond with eit wave speed.

McAteer CME Kinematics

–Kinematics is the study of the motion

–Energetics is the study of the forces which cause the motion.

•What forces govern the propagation? •What forces govern the expansion? from height time profiles -> acceleration profiles • What are we tracking? - image to image, - event to event, - study to study • Can we reduce the errors? • Are we capturing the full profile? - What about lower down?

combine with mass -> work done, force and power.

Known Knowns •Well characterized and large sample studies from 3-30RSUN •Well developed techniques to study energetics and kinematics

Known Unknowns •Behaviour at 1-3RSUN and greater than 30RSUN •Even at 3-30RSUN, –where do the forces act and over what distance? –when do the forces act and over what timescale?

Unknown Unknowns? -What is the initiation mechanism? -What is the CME - flare/filament link? -The ever-illusive current sheet - any other choice?

from stereo - better H-T low down, and multi direction. more automated tracking.

Steed

Howard

Events 17:00-18:30