Panel DiscussionGroups D, E, F, & G

Solar Cycle 24 Workshop

Napa, CA

12 December, 2008

Panel Members• Group D – Global Energetics

– Dick Mewaldt / Brian Dennis• Group E – Flares

– Eduard Kontar– Ryan Milligan– Albert Shih

• Group F – CMEs– Meredith Miles-Davey– James McAteer

• Group G – Microflares– Steven Christe– Iain Hannah

Group D - Global Energetics• Available Magnetic Energy 100%• Flare Energy

– Total radiated energy 10%• GOES Thermal 1%• Electrons 1%• Ions 1%

• CME 10%– Potential 1%– Kinetic 9%

• SEPs 1%– Protons– Heavies

TSI and VUV Radiative Energies During X-Class Solar

FlaresChris Moore

Undergraduate StudentU. of Iowa

(2 summers at LASP/U. of Colorado)

Phillip Chamberlin, Rachel Hock, Greg KoppLASP/U. of Colorado

04/21/23 Moore - Onset of SC 24

TIM/TSI scaling• Accuracy of 100 ppm (0.01%)

Relationships

04/21/23 RHESSI Workshop - Potsdam 7

Future ImprovementsContinuing measurements

– SORCE TIMNew measurements

– TSI• GLORY TIM (launch July 2009)• Imaging observations????• GONG to correct for p-mode noise????

– VUV• SDO EVE (launch Mid-2009 to early 2010)

Modeling– Flare Irradiance Spectral Model (FISM)

Mewaldt et al.

Group G - Microflares

• All flares are the same– Nano, micro, and “real” flares– Active region related– Flows– Nonthermal component– Polar jets

• Size distribution of flares– Flatter than 2

XRT NanoflaresP. Grigis

XRT NanoflaresP. Grigis

XRT Polar bright points and jetsJ. Cirtain

XRT Polar bright points and jetsJ. Cirtain

Group G – Microflares & Nanoflares

Group G – Microflares & Nanoflares

Evaporation in microflaresJ. Brosius & R. MilliganEvaporation in microflaresJ. Brosius & R. Milligan

Morphology of microflaresT. Shimizu

Morphology of microflaresT. Shimizu

Current sheets form readilyÅ. JanseCurrent sheets form readilyÅ. Janse

Nonthermal particles in nanoflares.Q. Chen

Nonthermal particles in nanoflares.Q. Chen

RHESSI Microflare StatisticsS. Christe & I. HannahRHESSI Microflare StatisticsS. Christe & I. Hannah

Impulsive energetic release (nanoflare, microflare, XBP, X class

flare) are all the same. Its all a matter of scale and energy.

HXR microflares/nanoflares do not heat the corona.

RHESSI Microflare StatisticsI. Hannah & S. ChristeRHESSI Microflare StatisticsI. Hannah & S. Christe

RHESSI Quiet Sun FluxI. HannahRHESSI Quiet Sun FluxI. Hannah

Group E - Flares

• Coronal hard X-ray sources - MARCO

• Source sizes & expanding magnetic fields

• Velocity vs. temperature & chromospheric evaporation– Need for continuous Hinode observations

• Gamma-ray spectra– Alpha/proton ratio– Proton spectrum

Non-thermal coronal sources

Number of nonthermal (accelerated) electrons must be of the same order as ambient thermal electrons or larger= > purely nothermal source? => acceleration region ? => EIS ratios to determine pre-flare densities?

Key Measurements & Candidate Instruments

Coronal magnetic fields ATST (Advanced Technology Solar Telescope),FASR (Frequency Agile Solar Radio observatory)EUV vector magnetograph

Plasma density, temperature , and flowsSoft X-ray imaging spectrometerEUV/UV imaging spectrographUV spectrometer/coronagraphWhite-light imaging coronagraph

Suprathermal seed particles UV spectrometer/coronagraphFocusing optics hard X-ray spectroscopic imager

Energetic electrons and ions Focusing optics hard X-ray spectroscopic imager Gamma-ray imaging spectro-polarimeterNeutron spectrometer

MAgnetic Reconnection in the COrona (MARCO)Science ObjectiveUnderstand the physics of the magnetic reconnection in the corona that initiates the release of energy for solar flares and coronal mass ejections (CMEs), and that leads to solar energetic particle (SEP) acceleration. Observational Objectives1.Measure the temperature, density, and magnetic field in reconnection regions and follow their spatial/temporal evolution2.Measure the density, speed, and direction of the slow (0.010.1 VA) and fast (~VA) plasma flows associated with reconnection3.Locate electron and ion acceleration regions4.Characterize the seed population for accelerated ions5.Determine the energy spectra and angular distributions of the accelerated electrons and ions, and their spatial/temporal evolution6.Determine the three-dimensional density structure, initiation time profile, and velocity of the shocks that accelerate SEPs7.Characterize the partition of energy amongst the various manifestations of energy releaseAssociated RFAs: F1, F2, H1, J2, J3

Mission Implementation

With the next generation of instruments it will be possible to probe reconnection, transient energy release, and particle acceleration in the corona. Simultaneous comprehensive measurements by multiple space instruments are needed, in conjunction with ground-based instruments (e.g., ATST and FASR) to measure coronal magnetic fields, morphology, etc.

MARCO combines the necessary space instrumentation on a single 3-axis stabilized spacecraft with an extendable ~20 m boom, in a low-Earth orbit.

• Total payload resources: ~2000 kg / 1500 W / 1 TB per day• Operation during solar cycle 25 starting in ~2020

Instrument Payload

To be determined from a science & technology definition team study, with many possibilities described in other quad charts in this Roadmap(e.g., RAMM, FOXSI, GRIPS, GRAPE, FACTS, UVSC, COMPASS).

Left: RHESSI/TRACE observations of gamma-ray line (blue) & hard X-ray continuum (red) footpoints straddling the flare loops, revealing both ion & electron acceleration related to reconnection.

Right: HINODE XRT image sequence showing evidence of magnetic reconnection.

Hinode flare operations

=> High temperature (T> 10 MK) line profiles of from Hard X-ray footpoints are predominantly stationary => weak evaporation?

Hinode flare operations

=> Continuous observations of an active region to have flare observations from the start to the end=>Not to rely on “flare trigger mode”

Magnetic field structure from RHESSI Hard X-rays

=> Magnetic field structure in the chromosphere => direct measurements of canopy heights?

18-22 keV 29-43 keV 43-75 keV 75-250 keV22-29 keV

1’’

Element abundances from gamma lines

=> Average ambient Mg and Fe abundance ratio consistent with photospheric abundances while ambient Si abundance appears to be closer to coronal. No consistent low FIP enhancement.

=> Average accelerated heavy ion (Ne, Mg, Si, and Fe)/O abundance ratio consistent with corona and photosphere but not impulsive SEPs.

=> New average accelerated alpha/proton ratio (~0.15 ) is elevated.

Flare gamma-ray observations

• Controversial statements?– The flare acceleration of ions and electrons to high

energies is directly proportional, but they interact at spatially separate locations.

– The ambient abundances are photospheric rather than coronal, and the flare-accelerated abundances do not agree with impulsive SEPs.

• New tools: TALYS, instrument response models• New instruments: FGST, GRIPS, and others

Final comment:

The number problem still unsolved for thirty years?

Group FGroup FOutstanding CME Science QuestionsOutstanding CME Science Questions

• How do we explain CME initiation?– Relating models/simulations to data– “Problem events”

• How do CMEs relate to other origins phenomena?– Flares, filaments, dimming

regions, coronal waves

• How do CMEs evolve?– Acceleration/deceleration– 3D Kinematics

CME Wish ListCME Wish List• Better data (future instruments)

– High cadence EUV (AIA)– Imaging spectrograph– Low-corona coronagraph– Vectormagnetograph (HMI)

• Analysis methods– QuantitativeQuantitative analysis!– Large-scale statistical studies– “Cradle to grave” case studies

• Meaningful metadata– Automated metadata extraction