Solar Cycle 24 Group F

From RHESSI Wiki

(Difference between revisions)
Jump to: navigation, search
(Wills-Davey Wednesday updates)
(WIlls-Davey Thursday edits 1)
Line 942: Line 942:
*** Microwave, HXR sources match  
*** Microwave, HXR sources match  
**** COMMENT: could be a limb effect
**** COMMENT: could be a limb effect
 +
 +
==Thursday==
 +
 +
===Session 5: 09:00 - 10:30 – Joint with J (Filaments)===
 +
 +
====Paulett Liewer (from J group):  Stereoscopic Analysis of  Filament Eruptions: Events of 19 May 2007 and 31 August 2007 ====
 +
* 19 May 2007
 +
** Standard filament model
 +
*** Before onset, energy stored in sheared field
 +
*** Onset: Reconnection
 +
*** Confined eruption a possibility
 +
*** Ejective eruption leads to post-eruptive arcades etc.
 +
** 3D reconstruction
 +
*** Pick out same points in 2 images, triangulate
 +
*** Q: how sure of same points in 2 images?
 +
**** Can be problem, some errors inherent
 +
** Have dynamic 3D reconstruction
 +
*** "Whip-like" filament eruption
 +
*** Height-time plot
 +
**** Prominence eruption much slower than CME(s)
 +
** Comparison with H-alpha, 304
 +
*** 304 shows "hot little threads"
 +
**** Lateral motion indicates eruption
 +
**** Lateral motion doesn\’t show up in confined eruptions
 +
*** During eruption
 +
**** See heating along filament channel
 +
**** See "patchy bright stuff" as opposed to double ribbons
 +
**** Filament doesn\’t show in H-alpha
 +
***** Heated?
 +
***** Doppler-shifted?
 +
** Multi-wavelength comparison
 +
*** Some bright features in chromosphere, others in corona
 +
**** Reconnection below filament
 +
*** Evidence of only one eruption
 +
* 31 August 2007
 +
** Tracking CME in coronagraph
 +
*** 3D reconstruction
 +
** Comparing prominence to cavity in 3D
 +
*** Evidence of twist?
 +
** Can see filament, cavity, CME
 +
* COMMENT: Looking for evidence of a second eruption in 19 May 2007
 +
** May be there, don\’t confuse with wave
 +
** Some think they see evidence of a pre-event erupting
 +
 +
 +
====Yingna Su: Observations of filament channels by Hinode/XRT and STEREO/EUVI ====
 +
* Connecting filament channels to CMEs
 +
* Looking at 8 filament channels
 +
** Some homologous
 +
** Close to disk center, better for magnetograms
 +
** Post-event arcades for 2 events
 +
** CMEs for 2 events
 +
* Comparing XRT and EUVI
 +
** Filament channels dark
 +
** See sheared loops in x-rays, not EUV
 +
*** Can be either stable or transient
 +
*** Sheared loops can constrain models
 +
** Post-event arcades
 +
*** Normally, no over-lying loops prior to filament eruptions
 +
*** See post-event arcades, but not in all events
 +
** Q: could lack of post-arcades, CMEs be due to failed eruptions?
 +
*** Possible, haven\’t looked
 +
** Emission asymmetric on either side of filament channel
 +
*** Curved loops one side, open loops other
 +
* Modeling
 +
** NLFFF model
 +
** Q: how did you constrain amount of twist in model?
 +
*** Fit to observations, but not really constrained yet
 +
** Bright curved loops could be lower legs of flux rope
 +
** Straight structures could be open
 +
* COMMENT: Asymmetric structure similar to SXT sigmoid observations
 +
** COMMENT: Can also see sigmoids in EUV
 +
* COMMENT: Instructive to look at cavity around prominence
 +
** Might explain asymmetry
 +
** Consider previous work by S. Martin
 +
** COMMENT: Model does show cavity
 +
** COMMENT: dark cavity due to optically-thin high central loops
 +
* COMMENT: Asymmetry may be due magnetic flux – should check magnetograms
 +
 +
====Vasyl Yurchyshyn: CME elongation s and orientations of post-eruption arcades ====
 +
* Considering halo-CMEs
 +
* Underlying flux rope model produces similar elongation, orientation of halo CMEs
 +
* CMEs highly structured, may be flux ropes
 +
* Looked at \~100 events
 +
** Using flare sites as origins
 +
** Distributed in AR belts
 +
* Measuring CME orientations
 +
** Find points on front "by eye", fit to ellipse
 +
** Assuming measuring the shock
 +
* Measure orientation of post-eruptive arcades
 +
* Compared CME orientation, post-eruptive arcade orientation
 +
** Good positive correspondence
 +
** Orientation provides information about magnetic field
 +
* Time profiles of individual CMEs
 +
** See CMEs change orientation in consistent way
 +
** COMMENT: doesn\’t appear to change linearly
 +
* COMMENT: "By eye" measurement susceptible to bias
 +
** A. Vourlidas thinks "completely unreliable"
 +
** M. Wills-Davey designing relevant automated CME tracking software
 +
* COMMENT: CME rotation makes sense
 +
** Other observational evidence consistent with rotation – filaments, EIT waves
 +
* Rotation rate distribution
 +
** Gaussian centered at -3 degrees/hour
 +
** Rotation rate vs. CME speeds
 +
*** Slow CMEs rotate slower, fast CMEs rotate faster
 +
* Evidence of twist-to-writhe conversion (Green et al. 2007)
 +
** Consistent with observations
 +
** Northern hemisphere, expect (-) helicity and vice versa
 +
* Comparing CME orientation to MC orientation, source surface neutral line orientation
 +
** Weak correspondence close in, better orientation at 1 AU
 +
** MC aligned with neutral lines at 1 AU
 +
*** Need time to get good alignment
 +
* COMMENT: importance of calibrated data
 +
** Importance may due to convolution of CME with vinietting (sp?) function
 +
* Q: Is complex propagation rate real?
 +
** No, likely scatter
 +
* COMMENT: rotation of EIT waves
 +
** Different rotations in different hemispheres
 +
** Rotation consistent with filament eruption rotation, MC orientation
 +
* COMMENT: Need fully automated detection techniques, should be concentrating on this
 +
** Error bars
 +
** MANY events
 +
** Rotation should be visible from all orientations (STEREO COR and LASCO)
 +
** Some work at Trinity on ellipse-fitting of halo CMEs
 +
 +
====Discussions:  Outstanding questions====
 +
* In new cycle, new approaches?
 +
** M. Wills-Davey – SAO designing automated methods for detecting CMEs, dimming regions, EIT waves
 +
*** Will get many different types of metadata (masses, 2D dynamics etc.)
 +
*** Will be able to do statistics
 +
** D. Webb – individual events still need to be studied in detail across multiple instruments
 +
*** Need both approaches
 +
*** COMMENT: should be able to do multiple instrument studies for large numbers of CMEs
 +
** A. Vourlidas – Individual events can tell us more about _physics_
 +
*** COMMENT: may not be representative
 +
** A. van Ballegoijen – Need to understand magnetic fields associated with CMEs
 +
** J. McAteer – Different people will usually get different interpretations
 +
*** Computer codes are reproducible
 +
*** COMMENT: But different computer codes can produce different results
 +
**** But codes can explain where differences come from
 +
** J. McAteer - Calibration should be sited more
 +
** T. Berger - Need vectormagnetograms for best analysis of flux ropes, filaments
 +
** B.C. Low – A few good events are the best for theory
 +
*** Shows that particular situation is possible
 +
*** COMMENT: But smaller, more run-of-the-mill events necessary for understanding physics better
 +
* Example TRACE movie of filament eruption, cavity, post-flare loops
 +
 +
===Session 6: 11:00 - 12:30 – Talks and Discussion===
 +
 +
====Yuming Wang:  An Analytical Model Probing the Internal State of a Flux Rope and its Application to CMEs====
 +
* Internal parameters
 +
** Polytropic index
 +
*** Tells us about heating
 +
** Lorentz force
 +
*** Tells us about expansion of CMEs
 +
* Not many studies considering global understanding (cradle-to-grave) of CME evolution
 +
* Motivation: Can current coronagraph observations be related to MHD?
 +
* Assumptions:
 +
** Axisymmetric cylinder moving out (see Powerpoint figure)
 +
** Self-similar evolution
 +
** Axial length proportional to distance
 +
*  Final equation involves:
 +
** Radial motion
 +
** Poloidal motion
 +
** Lorentz force
 +
** Thermal pressure
 +
* Example: limb CME in STEREO B
 +
** Advantages:
 +
*** Two viewing angles
 +
*** Broad FOV
 +
* CME dynamics tracked moving out (semi-automated)
 +
* Model of polytropic index
 +
** CME nearly isothermal in heliosphere
 +
** Implies some heating mechanism for expanding CME
 +
* Model of Lorentz force
 +
** Can\’t be ignored early on
 +
** Becomes essentially Lorentz-force-free in heliosphere
 +
** Lorentz force inward, prevents CME from expanding
 +
* Model of thermal pressure
 +
**  Pressure outward
 +
** Supports CME expansion
 +
* Model suitable for:
 +
** Axial-view CMEs (more accurate R and L)
 +
** Fully developed CMEs (outer corona and heliosphere)
 +
* Still to address:
 +
** Can this model address heating, thermal energy transfer?
 +
** Can study flux rope (CME) expansion
 +
** In-situ MC observations can be interpreted, compared
 +
** Better understand physics of CME initiation
 +
* Q: How find size of flux rope?
 +
** Radius and distance from coronagraph images
 +
** Use equations, approximations
 +
* Q: Do reverse-engineering model results fit data?
 +
* Q: how does model interact with solar wind, surrounding corona?
 +
** Solar wind not considered here
 +
** Boundary not studied
 +
** Only studying internal balance, structure
 +
 +
====Linda Hunt:  Discussion of thermospheric observations====
 +
* Working towards energy balance in thermosphere
 +
* Considering cooling of NO, CO2
 +
** Influence of solar events
 +
* May 17-22 2007 observations
 +
** Peak in NO flux at May 19
 +
** Peak later in Ap index – slight lag to NO flux
 +
** Happens to early to be associated with May 19 event
 +
* Discussion of Halloween storms
 +
** What is the lag between coronal observations and thermosphere measurements?
 +
* Feb 3-9 2008
 +
* April 23-29 2008
 +
* June 2-8 2008
 +
* Can see evidence of decrease in solar cycle in thermosphere data
 +
 +
====Alphonse Sterling: More on Filaments====
 +
* 18 April 1999
 +
** Large filament eruption
 +
** Dimming (evacuation?) along channel happens briefly
 +
** Post-flare loops in center of channel
 +
** Six hour slow rise
 +
* 28 Feb 2001
 +
** Filament eruption
 +
** Dimmings visible
 +
** Microflares affect slow rise
 +
* 11 July 1998
 +
* 2 Mar 2007
 +
 +
====Gemma Attrill: Discussion of 23 May 2007 Event ====
 +
* First showing movies from talk that didn\’t work in talk
 +
** Q: How to reconcile CME mapping back to dimmings?
 +
*** Diffuse wave actually maps better
 +
** Dimming region formation affects understanding of CME initiation
 +
* 23 May 2007
 +
** 195 movie
 +
*** Eruption to the south
 +
** XRT movie
 +
*** Ti Poly filter
 +
*** Short exposure time (not ideal)
 +
** Evidence of XRT front _lagging_ 195 front, and 195 front _lagging_ 171 front
 +
*** Contradicts fast-mode MHD wave theory – requires higher parts of wave leading lower parts (this is opposite)
 +
*** Contradicts Long et al. 2008 findings of cospatiality
 +
** Potential field map
 +
*** Large scale loops to East of wave origin
 +
** Filament eruptions
 +
*** Failed eruption had no wave, dimming
 +
*** Successful filament eruption had CME, wave, dimming
 +
**** Supports Cliver et al. 2005 finding that CMEs cause waves
 +
** Bright front maps onto CME legs
 +
** Strategic separatrices channel brightening to edge of coronal hole
 +
 +
===Session 7: 2:30 – 4:00 – Event Talk and Discussion===
 +
 +
====Angelos Vourlidas:  Overview of 02 January 2008 event, 31 August 2007event, 2 June 2008 event====
 +
* Advantages of using two spacecraft
 +
* 2 January 2008
 +
** EUVI shows CME initiation low down (very high cadence 171)
 +
*** Slow event - <100 km/s
 +
*** C1 flare
 +
** See loops collapsing, disappearing, reconnecting? Into cavity
 +
*** Gradual motion over first 56 minutes
 +
*** 187 minutes – core erupts
 +
*** 222 minutes -  CME evacuates
 +
** See reconnection to the North, same direction as coronal wave
 +
** COMMENT: Advantage of STEREO increasing separation – can determine limb magnetic field
 +
* 31 August 2007
 +
** Filament eruption
 +
** Filament visible on-disk in only one view
 +
* Most flares show some sort of ejection
 +
** COMMENT: No.  Most flares are confined
 +
* How to account for small CMEs?  Related to flares?
 +
* COMMENT: Waves accelerating particles may happen at same time as CME, but not the same event
 +
* With List for Cycle 24
 +
** Composition measurements of filament
 +
** Need to see current sheet behind CME, above flare
 +
** Want a mission with a coronagraph close to solar surface
 +
* COMMENT: Automated methods should map between instruments
 +
* COMMENT: Flares and CMEs can be distinct.  Shouldn’t generalize
 +
* COMMENT: Remember there are flares without CMEs
 +
** But flares could be confined ejections
 +
** Important to properly define flare
 +
* For CMEs, should remember to include non-magnetic forces
 +
* How reliably can we measure free magnetic energy?
 +
* Role of multipoles in CMEs?
 +
* Don’t believe GOES SXR curves, because of coronal background
 +
* COMMENT: Are flares episodic, or are they necessary for the dynamo, solar cycle?  Is the dynamo "driven evolution" of the corona?
 +
* 2 June 2007 event
 +
** Shows slow eruption
 +
** Well-tracked height-time curve
 +
** No evidence of eruption in corona
 +
** Not a backside event
 +
*** SOME DISAGREE
 +
** COMMENT: Can see coronal flaring etc. in STEREO A
 +
** COMMENT: Can have reconnection without a flare
 +
 +
====Nariaki Nitta: Discussion of 2 June 2008 event====
 +
* Images from 31 May 2008
 +
** Finds some corresponding features
 +
* Movie of 1 June 2008
 +
** STEREO A: 171 base difference images show CME ejection well
 +
** STEREO B: see filament on disk
 +
* Comparison with EIT  3 Nov 2000
 +
** Dimming happens fairly late, due to slow event
 +
 +
====Discussion====
 +
* Q: What\’s the point of Angelos\’ event?
 +
** CME without an on-disk signature
 +
** Models should be able to explain this
 +
** Possibly a non-magnetic mechanism
 +
*** DISSENTION
 +
* Vasyl discusses analysis of a similar event
 +
* N. Nitta – Correlation between CME speed and flare strength
 +
** But significant scatter
 +
** This event probably falls within scatter
 +
* R. Moore – Event probably due to weak field
 +
* N. Nitta – What determines magnitude of CME?
 +
* B.C. Low – Need to connect magnetic field to CME speed
 +
** M. Wills-Davey – Paper showing correlation between dimming region magnetic flux and CME speed
 +
* D. Webb – Are there two classes of events, or is there a spectrum?
 +
** M. Wills-Davey – Large-scale statistics!
 +
* A. Vourlidas – How can low-lying field remain stable with high-up evolution?
 +
 +
====Linda Hunt: More molecular measurements====
 +
* Extended time for May 22 2007 event
 +
** MAJOR NO flux visible on May 23-25
 +
** Matches Kp index well (no delay, not sure why)
 +
* 13-25 Dec 2006
 +
** Nice NO event on the 16<sup>th</sup>

Revision as of 01:11, 12 December 2008

Contents

McAteer Notes

INTRODUCTION

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' or tether cutting

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

rise of filament in AR is mins rise of quiescent filament is several hours.

also association with flux emergence / cancellation.

filament is tracer of the overlying loop?

WHAT WILL WE LEARN: how common is a slow rise? what triggers slow & fast rise phases?

where to go from here? Clearly Hinode and SECCHI 171 high 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.

Occams razor? why add in CME flanks and then introduce wave anyway? Overly complex?

Can also be viewed in XRT on 20-May-2007

WHAT WILL WE LEARN? New tests from multi viewpoint? tenuous results which may collapse in face of new data?

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.

WHAT WILL WE LEARN:

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 locating the solar source

ICME ejecta - components of ICME show a left -handed cloud (-ve helicity)

launch window determined - 80hours before, roughly noon 10-april 2006 no obvious cme signatures (flares, dimmings, etc) survey possible launch regions.

search for source region with -Ve helicity. only one possible no erupting filaments, or possible cmes (because of lack of launch, conclude a back-sided event)

find some evidence of cusp shaped loop - > eruption signature? without vector data- cannot rule out helicity problems.


WHAT WILL WE LEARN?

HOWARD source regions A skeptics view of flare-cme relationship

how do we define a flare and a cme? cme- outward propagation of brightness enhancement in WLC flare - brightening in cr, tr or coronal emmisison

associating lists is dangerous all current theories have a flare as necessary consequence of eruption, but not neccesaary cause and effect.

There are CME without flares -called backside, faint flare (not in GOES) there are cmes which have no chromospheric signatures - 'streamer blowout'

with stereo - we can see these are not backsided.

obvious controversy suggest we are a long way from solving this problem -different people see different conclusions from the same data!

WHAT WILL WE LEARN? Need to nail down an agreed definition? With STEREO we can rule out backsided possibility - can we also rule out the 'too low for GOES? If so, then we have a non-flare CME and we need a new approach.


VERMA A new classification of CMEs?

calculate escape velocity Alphonse- What about LOS projection? - not accounted for.

NEVCME 41%, mostly +ve accleration Ev CMEs 59%, half +ve, half -ve overall 68% show +ve acc

WHAT WILL WE LEARN:

LOS question is vital: problems with just looking at the stats, not looking at the data


EVENTS

WEBB - overall discussion and questions to be addressed

Types of CMES -limb (good for H-T) -earth directed OR spacecraft directed (good for connecting CME / ICME and finding source regions -cradle to grave events

What is source region? dimmings, waves, slow rises extents, locations flares, prominences cavities

How essential are current sheets? 9-Apr-2008 has well observed current sheet?

How do we define an ICME now that we can image ICMEs what do we see in HI and how does this compare to in-situ?

How essential are prominences & eruption - joint with WG J

Campaign Focus events WHI 20 march -16 april 2008 9 apr 2008 event

Events Obs Science

2006 dec 13-15 2 X-ray flare near sun center ICME flux rope, SEP at earth, STEREO space weather event. secchi.nrl.navy.mil/spwx/

2007 Jan 24-25 2 CMEs east limb. SECCHI, SOHO, SMEI papers: Harrison et al, Lugaz et al, Webb et al

2007 May 19-22 2 events near sun center, HINODE & STEREO 3D view of filament lift off

2007 May 23 AR on west, wave, prom eruption, CME HINODE & STEREO

2007 Nov 14-18 3 events, 1 at sun center

2007 Dec 31 east limb

2008 March 25 east limb, during WHI

2008 April 9 west limb, XRT, EIS, SECCHI, UVCS interaction with CH

2008 April 26 near sun center, fast cme & euv wave

2008 May 17 sun - STEREO interaction

2008 Jun 6 magnetic cloud at STEREO B

2008 Feb 4-8 2008 June 2-6 wood et al. 2008 robbrecht et al. 2008


WHAT ARE THE ISSUES? connection with flares - few large (>M) flares since STEREO launched.

LI - May 19, 2007 CME & B field of AR 10956

B9 flare, 960Km/s sun center AR pre eruption sigmoid structure in XRT B field topology - Li et al, ApJL 2008 classic breakout model configuration?

total B flux in region decreased 17% 48 hours before flare, so weakening of overlying field?

pre flare brigthening - tether cutting?


STERLING - May 20, 2007

B7 flare, well observed with TRACE, STEREO pre flare surges. reduction in B field

Angelos- constant flux cancellation, so what can we say quantitatively?

EIS box also rastered over this region.

-persistent red shifted flow and non thermal broadenings

-strongest shifts are 20Km/s

-typical densities of fewX 10^9 cm^-3

WHAT WILL WE LEARN?

Angelos - anything new?

Sterling - can we predict eruption?

Cartoon picture explanation. again person A see different conclusion from same data than person B.

June 2

FILAMENTS , (HOST J)

LIEWER - Stereoscopy

standard model - energy in sheared field marked by filament get confined eruption (surges) and ejective eruption

stereoscopy - -tie point depends on seeing the same feature correctly - constrain it to a 1D problem using the epipolar lines

compare to li et al (2008)

reconstruct the filament and show that H-T shows that ejection follows reconnection consistent with standard model velocity around 100km/s (much slower than CMEs) - kilpua et al. SP 2008)

again different people see different things in the same data- can we get a quantitative test?

compare h-alpha to euv images to discover when filament moves up / moves out of bandpass.


august 31, 2008 promininence eruption on SW and nice CME 3-part structure good for 3D tracking

SU - Filament Channels

sheared loops with filament channels not all filament eruptions are associated with post-event arcades.

emission on two sides is asymmetric

fc are dark channels. sheared loops in xray, not in euv normally no overlying loops observed both emission and 3d B configuration is asymmetric

Sterling - sigmoids not in EUV, so the sheared loops are hotter.

Comment: What about april 25, 2007 -good cavity above the prominence. dark cavity - flux rope, low cavity, also density at tops is low because they are so high (several scale heights)


YURCHYSHYN - Halo-CME orientation vs. underlying flux rope orientation

cme elongation and flux rope orientation select 100 events many halo cmes can be approx by ellipse (zhao et al 2002, xie et al 2004 events from tripathi et al. 2004

manual fitting of ellipse and fitting parameters. measure orientation fo arcade from TRACe and MDI

plot orientation of CME against orientation of arcade shows nice correlation.

also shows that cme orientation changes with time - gradual rotation. CMES tend to rotate towards equator. agrees with negative helicity in N, filaments rotate CCW

angelos - dependent on the person fitting the eclipse and calibration level of images. need automated fitting processes.

WHAT WILL WE LEARN - need automated processing on well calibrated images.

what is full connection of orientation of flux rope / NL and Magnetic cloud ?


NEW CYCLE APPROACHES -fully automated approaches -full appreciate the cailbration

individual events good for getting at the physics, but we end up ignoring the 'boring' events

MODELS

WANG - An Analytical Model Probing the Internal State of CMEs

internal properties of model -polytrpic index -lorentz force how do the forces change as CMEs propagate?

how well do we know the internal state?

analytical model - axisymmetric cyclinder, self similar evolving, axial length proporitonal to distance from Sun

apply model over large radial distance.

results (1) polytropic index decrease 1.35 to 1.0 (decreases quickly at the beginning) (2) Lorentz force to thermal pressure ratio decreases from 1.0 to less than 0.1 at 70R_s (3) loretnx force is inward, thermal pressure is outward.

Future: study axial CMEs and fully developed CMEs Address heating or thermal energy transfer, expansion of flux ropes, in-situ and infer some physical mechanism regarding initiation.

Angelos: thermal component agrees with in-situ

EXTRA DISCUSSION

HUND thermosphere studies

data from 2002-> cooling by NO delays from KP index curve to NO cooling curve normally 2 days to cme

This is the CME hitting the earth.

also CO2 data avaliable.

alphonse: terrestrial consequences? angelos: primary driver is the EUV. russ: we are seeing CIR coming around, and not detected here.

OVERVIEW

Vourlidas Questions

31-Aug-08

20070831- filament lift off kinked feature in B, not A

so are all events kinked?

why are there 2 types of flares? eruptive / confined gradual / impulsive? available B energy? measure Free B energy? access to open field lines?

do flare accelerated particles have access to CME? how do they escape? how many are there?

what is CME -flare lightcurve connection? When does fluxrope form? is there a single initiation mechanism?


wish list? cme-flare connection? behind the cme / above the flare? hrx and radio wish? eclipse like (white light) imaging of corona (0.03 - 3Rsun)

reliable estimate of B non-potent improved extrapolation wish? B field obs above canopy into TR

high cadence EUV obs during early phase at low heights

improved energy measurements better flare energy estimates? CME composition in early phase.


questions? does fluxrope preexist? what can we learn from acc profile? what is role of B_bkg in flares / cmes? are there flares without cmes? what is role of non-B forces in eruption? do we understand 3d reconnection? energy release and partition? reliabily of B field, helicity? role of multipolar system in flares/ cmes? how reliable are goes / sxr curves? what is the role of flares/cme in dynamo-driven evolution of the corona?

define a flare and a cme? all one process - either liberate energy in photons, or mass, or both?

june 2nd event (COR2). seemingly no flare / dimming / filament.

Wills-Davey Notes

Tuesday

Session 1: 14:30 - 16:00 - Intro Talks

Alphonse Sterling: Introduction to Group F Agenda

Alphonse Sterling: The earliest phases of solar eruptions

Gemma Atrill: Coronal ’waves’ and dimmings - what can they tell us about their CME counterparts?

Session 2: 16:30 - 18:00 - Intro talks (continued)

James McAteer: Kinematics of Coronal Mass Ejections: Theory and Observations

Kimberley Steed: Solar source of a magnetic cloud; overview of 13 April 2006 event

Russ Howard: A skeptic’s view of CME-Flare relationship

Wednesday

Session 3: 09:00 - 10:30 – Intro talks (continued), Events Talks

Virendra Verma: On the New Classifications of Solar Coronal Mass Ejections Based on LASCO/SOHO Observations (10 min)

Dave Webb: Possible Events


Yan Li: Overview of 19 May 2007 event

Alphonse Sterling: Overview of 20 May 2007 event

Session 4: 11:00 - 12:30 – Joint with E (Flares)

NOTE: Group E didn’t know we were coming. Not much CME discussion.

Eduard Kontar: X-ray Measurements of Magnetic Field and Density Structure in the Chromoshere

S. Masuda: GEMSIS-Sun: Modeling particle acceleration and transport in solar flares

Pascal Saint-Hilare: X-ray emission from a current sheet in the wake of a CME & Long data accumulations with RHESSI

Lindsay Glesener, Sam Krucker: Coronal HXR sources

Thursday

Session 5: 09:00 - 10:30 – Joint with J (Filaments)

Paulett Liewer (from J group): Stereoscopic Analysis of Filament Eruptions: Events of 19 May 2007 and 31 August 2007


Yingna Su: Observations of filament channels by Hinode/XRT and STEREO/EUVI

Vasyl Yurchyshyn: CME elongation s and orientations of post-eruption arcades

Discussions: Outstanding questions

Session 6: 11:00 - 12:30 – Talks and Discussion

Yuming Wang: An Analytical Model Probing the Internal State of a Flux Rope and its Application to CMEs

Linda Hunt: Discussion of thermospheric observations

Alphonse Sterling: More on Filaments

Gemma Attrill: Discussion of 23 May 2007 Event

Session 7: 2:30 – 4:00 – Event Talk and Discussion

Angelos Vourlidas: Overview of 02 January 2008 event, 31 August 2007event, 2 June 2008 event

Nariaki Nitta: Discussion of 2 June 2008 event

Discussion

Linda Hunt: More molecular measurements

Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox