The Magnetic and Energetic Connection Between the Solar Photosphere and Corona (Bill Abbett, K.D. Leka)
In this session, we tie the two approaches together, and focus on several inter-related questions relevant to the physics of active regions and eruptive events: Can the observed surface field in an active region lead to an accurate description of the magnetic structure of the overlying atmosphere? What type of modeling is required to reliably reproduce the dynamic evolution of active region magnetic fields in the solar atmosphere? Can measurements of the surface fields and flows over time produce an accurate accounting of quantities such as magnetic helicity and free energy? Presentations will address these questions using both theoretical and observationally-based approaches, and we invite discussion on the implications and limitations of each method.
Active Region Flux (Holly Gilbert, Nick Arge)
- Does open magnetic flux come from active regions?
- If open magnetic flux comes from ARs, then how much?
- How does it change over the solar cycle?
- Is there a good observational way to identify the open regions?
- Are models actually capturing open regions?
- What is the connectivity between open and closed regions?
- Composition and charge states?
Filament Dynamics (Holly Gilbert, Nick Arge)
This session will focus on topics related to these issues:
- Dynamics
- Nature of eruption
- Topology
- Heating
Challenges from last year that will be addressed by the speakers:
- How is activation related to eruption and CMEs?
- How is reconnection related to the success of eruption?
Heliospheric Plasma Sheet (Ian Richardson and Angelos Vourlidas)
- What is the role of reconnection at the HPS?
- Are HPS observations dominated by spatial or temporal variations (or both)? Are there multiple current sheets? What plasma instabilities are observed at the HPS?
- How do ICMEs interact with the HPS, and what are the consequences of this interaction? Does the HPS “order” the properties of ICMEs?
- What is the thickness of the HPS?
- Are there solar wind composition anomalies associated with the HPS?
- What are the characteristic solar features associated with the base of the HPS? What is the relationship between the streamer belt and active regions?
- Is there a systematic north-south asymmetry of the HPS?
- What is the effect of the HPS on the propagation of shocks, ICMEs, and energetic particles? Can the HPS influence the geoeffectiveness of shocks/ICMEs and energetic particles? What can models tell us about these processes?
Magnetic Data Inputs to Global Models (Ilia Roussev, Nick Arge, K.D. Leka)
While at the previous meeting we focused more on the observational techniques and methods in gathering and analyzing magnetic data, this time we will focus more on the modeling efforts that have been done lately. The key questions to be addressed during the session are:
- What magnetic data are best suited for the models (local and global)
- What extrapolation models best describe the physical state of the coronal magnetic field?
- How to incorporate vector magnetogram observations as well as GONG data into numerical models?
Origin of Structure in the Solar Wind (Joe Borovsky and Nick Arge)
There will be discussions to assess the feasibility and usefulness of a campaign to focus high-resolution telescopes onto the solar footpoints of L1 and to coordinate those telescope observations with in situ measurements made by the ACE and Wind spacecraft and with analysis of the driving of the magnetosphere by the observed solar wind. A strawman campaign is the following:
- Use the Wang-Sheeley-Arge mapping technique to specify two locations on the solar surface: (i) the location right now where a magnetic-field line from L1 has its footpoint on the sun and (ii) the location right now where plasma is lifting off the sun that will hit L1 in 3 or 4 days.
- Point high-resolution telescopes right now at those two points and collect observations. The telescopes may be TRACE, Hinode, KPVT, SST, EIT subfield, etc. With (1) and (2), determine what phenomena on the surface of the sun (magnetic-carpet dynamics, granulation, activations) are associated with what features in the solar wind (velocity, ionic composition, shrahl, entropy density, core electrons, magnetic structures, helicities, Alfvén-wave flux, etc.).
- Bring the GEM community and their data sets into this campaign to look at the reaction of the Earth’s magnetosphere and ionosphere to the solar-wind structures.
- Using CCMC, simulate the heliosphere (ENLIL) and the solar-wind-driven magnetosphere (BATSRUS and OpenGGCM). The ENLIL simulations could provide insight into the L1-to-Sun mapping and the BATSRUS and OpenGGCM simulations could provide information about the effects of solar-wind structure (arising from various types of regions on the sun) on the near-Earth environment. These simulations could be run by SHINE and GEM students, with various students signing up to simulate various time intervals.
Is the Ubiquitous Suprathermal Seed Population Generated in the Corona or Interplanetary Medium? (Matthew E. Hill, Dennis K. Haggerty)
A fundamental and unresolved question highlights the need for this session: Are suprathermal (ST) ions predominantly accelerated in the low corona and then transported outward or are they accelerated throughout the corona and heliosphere? (Or both?) To understand this we must measure the ST ion spectra and composition from the low corona to the middle heliosphere and examine (to try to untangle) the temporal variations. The observations must be explicitly gathered for comparative study so we can enable a theoretical analysis.
The approach of this session is to bring together remote sensing and in situ measurements of suprathermal ions from the corona to interplanetary space to allow direct comparisons. We will also use the existing observational constraints to select from various candidate theories explaining the temporal and spatial dependence of ST ions.
Turbulence and Coronal Heating (Ben Chandran, Joe Giacalone)
This session will address the viability of turbulence as a coronal-heating mechanism, and will focus on the following questions:
- Can turbulent heating explain the observation of large perpendicular ion temperatures in the corona?
- Can turbulent heating explain the preferential heating of minor ions?
- Does coronal turbulence involve the cascade of wave energy to frequencies comparable to the proton cyclotron frequency?
- Is there enough power in coronal turbulence to explain coronal heating?
- What is the frequency spectrum of the waves that are launched into the corona from the Sun?
- How does the turbulent-heating model stack up against competing models, such as shock-heating models?
Shock geometry and particle injection at Shocks and upstream/downstream phenomena (Gang Li, Nathan Schwadron)
The session will concentrate on shock acceleration in gradual SEP events. This session will:
- answer the key question the session will address is “is 1st order Fermi acceleration the major player for particle acceleration in large SEP events?”
- relate particle observations and wave observations at a CME-driven shock or an interplanetary shock. Particle observations include ion species, particle spectra, etc. Wave observation include upstream and downstream wave power. Observations from ACE, WIND, GOES spacecraft will be discussed.
- review some recent progresses on the theoretical and modeling of gradual SEP events. Theories and modelings of particle acceleration at both quasi-perpendicular and quasi-parallel shock will be presented. The role of upstream turbulence in accelerating particles will be discussed. The “discrepancy” between observations and theoretical predictions will be re-examined.
Interpreting Radio Measurements (Justin Kasper, Holly Gilbert)
The objective of this session is to discuss observations that make use of radio observations (imaging and spectroscopic) to connect the corona and interplanetary space. Topics to be discussed include the connection between radio emission and particle acceleration, coronal mass ejections, and the magnetic field and density structure of the corona and solar wind. This session will highlight recent theoretical work and radio observations, with an emphasis on the value of combining radio observations with other data including coronagraph, x-ray, and in situ particle and shock measurements.
Is the open flux in the heliosphere conserved? (Matt Owens, Dennis Haggerty)
This session will attempt to address the question of open flux evolution: Is open flux conserved from cycle-to-cycle, or is the flux in the heliosphere destroyed and recreated over the solar cycle? The invited speakers will provide insights of open flux variation at the photosphere, in the corona and heliosphere. We hope to have contributions on a wide range of topics connected to the issue of open flux evolution, including observations, modelling aned theory applied to the photosphere, corona, heliosphere, cosmic rays, etc.
CME Dynamics (Angelos Vouridas, Ilia Roussev)
This session addresses issues on the CME dynamics during the early phase of the event. In particular, we focus on the acceleration profile of the CME low in the corona since both STEREO and Hinode will provide us with a much better coverage of this part of the solar atmosphere. Some of the questions we will like to address are: How or does it relate to the initiation mechanism(s)? Can we use it to discriminate among different initiation models? Can it tell us anything about the energy partition during the early history of the ejection? Both models and observations will be discussed. We invite researchers with an interest in this topic to participate in the discussion.
The “Tell-Tale Topology” for CME Initiation (K.D. Leka, Holly Gilbert)
What does it take to initiate a coronal mass ejection? Models and observations have progressed to where both quantitative and qualitative predictions can be tested. Have we made any progress? Can any model now be adopted as truth? Can we throw any out? We invite discussion regarding the state of the models, new models, new observations, new observations, and how to better design new observational tests given the new Stereo, Hinode, and upcoming SDO missions.
Shocks in the Corona (Angelos Vouridas, Ilia Roussev)
This session continues the theme of coronal shocks from last year’s session. This time we focus on shocks low in the corona. One of the main discoveries from SOHO/EIT was the existence of propagating wave-like disturbances from flaring sites which are always accompanied by CMEs. Although, we have collected more than 10 years of observations of these so-called “EIT-waves” , their nature still eludes us. Are they shocks or waves? Are they the coronal footprint of the CME? How do they relate to waves in other parts of the atmosphere (Hα, photosphere)?
CME-ICME Connections (Zoran Mikic)
The focus of the team will be a detailed study of the CME event of May 13, 2005.
- Which characteristics of the magnetic field near the Sun determine the geoeffectiveness of ICMEs?
- How does a magnetic cloud expand from its origin in the low corona into interplanetary space?
- What is the relationship between the magnetic field observed in a magnetic cloud to that in the source region at the Sun?
- What is the topology of the magnetic field lines that connect the magnetic cloud with the Sun and the outer heliosphere?
- Do different CME initiation mechanisms predict different ICME signatures? Can they be used to discriminate between models?
- What reconnection processes are taking place during the eruption of the CME and its liftoff? How does this reconnection transfer magnetic field and electric current from the active region and the overlying large-scale field into the magnetic cloud?
CME and SEP modeling of the April 21, 2002 SEP event (Mihir Desai, Gang Li)
Reliable prediction of key SEP properties, (e.g., peak intensity, spectral variability, and heavy ion composition) depends on addressing a number of cross-disciplinary topics that are the prime focus of the SHINE community:
- model the eruption, propagation, and evolution of the CME and its shock through the interplanetary medium
- specify key properties such as mass, speed, and kinetic energy of the CME and the interplanetary shock near the Sun and at Earth
- characterize the ambient solar wind plasma, the magnetic field turbulence, and the interplanetary suprathermal ion population through which the CME and its shock propagate en route to Earth
- model the injection and acceleration of SEPs at the CME-driven shock and their subsequent transport to 1 AU.
The session will bring together remote observations of the solar magnetic field, coronagraph observations of CMEs with in-situ measurements of the solar wind plasma and magnetic field and SEPs, and use these to drive, constrain, and validate a variety of end-to-end CME and shock acceleration models. In particular, this session solicits broad input from the SHINE community while discussing recent results obtained by NASA’s Living With a Star TR&T SEP Team with particular emphasis on the April 21, 2002 SEP SHINE campaign event.
Towards Community Models (Jon Linker)
Models and simulations offer important tools for furthering our understanding of the space environment. This is particularly true for the SHINE community, where present and future solar/heliospheric missions provide diverse observations, and models are necessary for placing these measurements in context and obtaining a coherent picture. Traditionally in our community, the users of models/simulations have primarily been the model developers. Sophisticated models that are widely available and used by the community as a whole can have far more impact on the advancement of our science. This has been recognized by our funding agencies in the establishment of the Community Coordinated Modeling Center (CCMC), and in recent model development programs (DOD MURI, NSF CISM, and NASA Strategic Capabilities). The purpose of this session is to generate discussion on how to more widely disseminate models in the community, and to guide future model development so it is more responsive to community needs.
Electron-rich and/or He3-rich impulsive events (Dennis Haggerty, Gang Li)
- To understand the relative timings and sequence of various phenomena (injections of ions and electron, as well as the initiation of radio bursts, etc).
- What does the over abundance of He3 tell us about the acceleration process? How can one use He3 observations to promote or debunk certain acceleration mechanisms.
- Are there some solar surface observations (such as jet features at the boundary of active region) can be useful in deciphering the underlying process. Is there any observational evidence (one way or another) that there is always a CME involved when a impulsive He3 event is observed?
- What are the relationship between He3 and electrons? Statistically, how many electron-rich events are He3 deplete? For those events without He3 but electrons, is the acceleration similar to those having He3?
- Do we understand the relationship between electrons and type-III radio bursts, what population of electrons cause type-III radio bursts?
- Do we understand the role of open magnetic field lines in the eventual observation of electrons and He3 at 1 AU?