SHINE 2011 Sessions

Click on links to view session descriptions below.

1. Bridging the Great Divide: Linking the Solar Dynamo to the Dynamic Heliosphere
2. Comparing and Validating Models of the Corona and Inner Heliosphere
3. The Role of Magnetic Geometry and Reconnection in the Origin of the Slow Solar Wind
4. Coronal mass ejections without photospheric/chromospheric signatures
5. Multi-viewpoint observations of Solar Energetic Particle (SEP) events
6. Assessing the Contribution of Heliospheric Imaging in Improving Space Weather Prediction
7. The Nature of Coronal Mass Ejections: Heliospheric properties from remote-sensing observations and their relationship to in situ signatures.
8. Particle Acceleration and Transport in Flares and their Relation to SEP events
9. Coronal Magnetic Fields: What are we learning from CoMP observations?
10. What IS a coronal hole?
11. The Dissipation of Solar Wind Turbulence
12. The rise of solar cycle 24: Magnetic fields from the dynamo through the photosphere and corona and connecting to the Heliosphere
13. Flare Classification in the Era of Global Coverage of the Sun


1. Bridging the Great Divide: Linking the Solar Dynamo to the Dynamic Heliosphere
Mark Miesch & Ofer Cohen

Session Description

Both sub-sessions will emphasize outstanding problems with current paradigms and what steps are needed to make progress, both from an observational and a theory/modeling perspective.

Sub-Session 1: Origins and Manifestations of the Solar Cycle Monday, July 11, 2:00-5:00pm
Discussion leaders: Mike Thompson and Andres Munoz-Jaramillo

This sub-session will focus on the fundamental physical processes that give rise to the solar activity cycle and how these processes are manifested in the solar interior and atmosphere. Questions to be addressed include:

1) How is the solar cycle established? What are the triumphs and tribulations of current solar dynamo models? What observations are needed to provide new insights?

2) How does the meridional flow regulate the transport of photospheric and sub-photospheric magnetic flux and what role does this play in the operation of the global dynamo?

3) How do magnetic activity patterns observed in the photosphere and corona reflect the inner workings of the dynamo? Conversely, how are dynamical processes in the deep solar interior as exhibited by dynamo models manifested in the photosphere and corona? What observational constraints does helioseismology provide on the operation of the dynamo and how might these improve in the future?

4) How and why might one solar minimum be different from another? What might observations of the recent minimum between Cycles 23-24 tell us about the underlying dynamo mechanisms?

5) How might observations of stellar magnetic activity provide new constraints on the solar dynamo?

Sub-Session 2: From the Convection Zone to the Heliosphere Tuesday, July 12, 9:45am-12:45pm
Discussion leaders: George Fisher and Janet Luhmann

This sub-session focuses on how magnetic activity in the solar interior and photosphere is conveyed to the overlying atmosphere and ultimately to the heliosphere. Questions to be addressed include:

1) How are magnetic flux, energy, and helicity transported through the photosphere, chromosphere, transition region, and corona? What implications does this transport have with regard to magnetic topology, magnetic connectivity, and energtics (dissipation, transmission, mode conversion)?

2) How does the time-varying structure of the heliosphere reflect the global-scale internal field? Is there a systematic time delay between the evolution of the internal and external field?

3) Do flux emergence and CMEs play a critical role in the dynamo by providing a release mechanism for magnetic energy and helicity? Might the dynamics of the corona influence the dynamo in other ways?

4) Does the Sun have a "ground" activity state? How do small-scale and large-scale magnetic field components interact and how does each influence the structure and evolution of the transition region, corona, heliosphere, and solar wind?

5) How do long-term variations in solar activity influence the structure of the heliosphere and the space environment of the Earth?

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2. Comparing and Validating Models of the Corona and Inner Heliosphere
Peter MacNiece & Gilbert

Session Description

Discussion leaders (subject to additions) : Peter MacNeice, Pete Riley.

The goal of our session is to set up a community-wide two year validation study of models of the ambient corona and inner heliosphere. Each model developer has published test results and validation studies of their own model, and the CCMC has begun a program of independent validation and definition of metrics from a Space Weather forecasting perspective.

In this session we wish to take the next step - pose a set of common problems, designed with the insights of the developers and interested users, that will enable all models in this class to be compared and will provide a clear picture of the relative strengths and weaknesses of different model approximations and algorithms. Experience suggests that as modeling communities mature, they benefit greatly by going through the exercise of direct comparison of competing models. Our community has yet to do this.

The modeling landscape in this area is likely to be transformed over the next few years for two reasons, the delivery to the community of new Strategic Capability models funded through the LWS TR&T program, and the deluge of new magnetogram data which is expected from SDO. For these reasons we believe it is timely to begin to put in place the next generation of validation procedures for these models.

At last years SHINE, we held an informal session to sound out the model developers who were in attendance on the value of this session, and the suggestion met with general approval. At this summer's meeting we are ready to begin in earnest.

Our specific goals for this summer's session will be to 1. Discuss the selection of a set of problems to be run by the participating models 2. Establish a timeline for the study milestones 3. Discuss the study logistics

  • posting/dissemination of results
  • achieving uniform presentation
  • telecon schedules and setup
  • ideas for eventual publication of results.

Our session is a half-day session on Wednesday, July 13.

We hope to encourage you to participate in this session and in the subsequent validation effort. Even if you are not planning to attend SHINE this year, we would welcome any input you might have to our discussion, and if you are a model developer, would invite you to participate in the validation study as it progresses.

We plan to follow the SHINE philosophy of encouraging the maximum possible discussion. Our hope is that after some brief (10 minutes or less) remarks by the discussion leaders, the session will be open for general discussion. You are invited and encouraged to bring along a slide or two to support any discussion points that you would like to raise.

If you would like us to reserve a 5 minute slot for you to voice your opinions please let us know and we will make sure that it happens.

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3. The Role of Magnetic Geometry and Reconnection in the Origin of the Slow Solar Wind
Justin Edmondson, Ben Chandran

Sessions Description

The physical mechanisms that generate the solar wind, and in particular the slow solar wind, are not well known. Processes that may play an important role include the emergence of new magnetic flux from the solar interior, reconnection at low altitudes in the solar atmosphere, and reconnection within a coronal magnetic field with a highly complex topology. This session will critically assess the relevance of flux emergence, reconnection, and magnetic geometry to the generation of the slow solar wind, with a focus on the following scientific questions:

1) How much power is associated with reconnection throughout the corona, and is this energy release sufficient to power the solar wind?

2) What fraction of the free magnetic energy released by reconnection in the corona goes into heat, and what fraction goes into waves?

3) How much of the energy released by reconnection in the solar atmosphere escapes along open field lines into interplanetary space?

4) What is the role of metrics of coronal magnetic geometry and topology, such as the "squashing factor", in determining the energy state and potential release of free magnetic energy in the low corona?

The invited discussion leaders for this session will be John Linker, Nathan Schwadron, Marco Velli, and Thomas Zurbuchen.

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4. Coronal mass ejections without photospheric/chromospheric signatures
Alexei Pevtsov, Vasyl Yurchyshyn, & Vourlidas

Session Description:

Typical CMEs are clearly associated with flares and/or filament eruptions. Although the exact trigger of a CME eruption may be debatable, there is always some noticeable evolution in the photosphere (e.g., new flux emerging or build-up of magnetic shear etc.), chromosphere (e.g., slow rise of a filament), or corona that heralds the CME eruption. And there are always notable changes in the corona and the chromosphere immediately after the CME eruption, such as, for example, post-flare loops, arcade brightening, cusps, and/or coronal Moreton/EIT waves indicating a coronal/chromospheric response on a CME eruption.

Recent period of low solar activity had revealed a new type of coronal mass ejections (CMEs), when no flare or filament eruption is observed. Furthermore, these CMEs, christened as "stealth CMEs" or "CMEs from nowhere", do not exhibit a clear post-eruptive signatures typical for "regular" CMEs.

For example, Robbrecht, Patsourakos, and Vourlidas (2009) reported STEREO observation of a CME without a clear signature of solar source region in the photosphere, chromosphere, or low corona. Stealth CMEs may not be uncommon. Recent study by Ma et al (2010) suggests that about one third of CMEs do not exhibit any coronal signatures, and thus, can be classified as "stealth". Pevtsov, Panasenco, and Martin (2010) have suggested that such CMEs may be associated with eruption of empty filament channels.

The goal of this half-a-day session is to discuss the physics of stealth CMEs and their importance for the Space Weather. What is the origin of stealth CMEs? Do they have a different magnetic topology as compared with the regular CMEs? Can these CMEs help in understanding the regular CMEs? Are there distinct (albeit hard to observe) chromospheric/coronal settings that may indicate stealth CME eruption? Should one expect a different geomagnetic response from such CMEs as compared with the "typical" CMEs? These or any other relevant questions are opened for discussion.

The session will start with brief (10 minutes) opening remarks by the discussion leaders followed by a general discussion. If desired, you will be able to support your points with one or two slides. If you would like to make a longer (5 minutes) presentation please let the organizers know, and we will set aside time for your presentation. One of possible outcomes of this session could be a selection of events for followed-up case study. You are encouraged to think about possible candidate events for such case study.

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5. Multi-viewpoint observations of Solar Energetic Particle (SEP) events
Eric Christian & Georgia de Nolfo & Dennis Haggerty

Session Description

STEREO has given us a new tool to look at SEP events, a multi-viewpoint tool. This session will be divided into three half-days, each of which will have a different focus. The first period will focus on the composition of the SEPs, the second will focus on what we have learned from the combination of in-situ and remote sensing of CMEs and SEP events, and the third will focus on why some SEP events are observed over a wider longitudinal extent than expected.

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6. Assessing the Contribution of Heliospheric Imaging in Improving Space Weather Prediction
Doug Biesecker & Simon Plunkett

Session Description

An array of imagers (SMEI, SECCHI) has been monitoring the inner heliosphere over the last 4 years. Many Earth-directed Coronal Mass Ejection (CME) events have now been observed from a variety of viewpoints both along and away the Sun-Earth line. The heliospheric imagers allow us to directly trace the propagation of a given CME all the way from near the Sun to the Earth. The multi-viewpoint observations have led to the development and testing of various methods for deriving the propagation direction, speed, size and time of arrival of the CMEs at Earth. The results can be compared directly to in-situ detections to assess their validity. In this session, we propose to discuss these results in order to assess the improvements in Space Weather forecasting brought about by heliospheric and multi-viewpoint imaging and identify the areas where open issues remain. We propose to format the session as a discussion focused on the following questions:

1. What are the improvements in predicting the CME arrival time and speed using SECCHI and SMEI? - How can we assess the degree of improvement?

2. What is the optimum CME shape for input to operational models such as ENLIL? Cone, fluxrope model, something else?

3. What is the best distance range for a successful Time-of-Arrival prediction? When the CME reaches the edge of the coronagraph field of view (~15Rs), or the inner heliosphere (say 60 Rs)? a. What constitutes a successful prediction?

4. How does the ambient environment affect the predictions (e.g., through drag, solar wind interactions, multiple interacting CMEs)?
a. Are there conditions existing models do not or cannot account for?

5. For operational purposes, is imaging from a platform away from the Sun-Earth line (e.g., from L5) sufficient or do we still need imagers along the Sun-Earth line?

6. Is an empirical approach, based on elongation-time measurements, sufficient for operational prediction or do we still need to deploy MHD modeling?

We invite brief contributions (ideally < 3 slides) on any of these topics for presentation and discussion during the session. Please send your proposed contributions to Simon Plunkett (simon.plunkett@nrl.navy.mil) or Doug Biesecker (doug.biesecker@noaa.gov).

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7. The Nature of Coronal Mass Ejections: Heliospheric properties from remote-sensing observations and their relationship to in situ signatures.
NoƩ Lugaz (UHI), Ying Liu, & Mark Popecki

Session Description

The aim of this session is to explore ways to improve our understanding of CME properties and propagation from the Sun to the Earth by combining remote-sensing observations with in situ measurements. We will focus on how the CME properties can be determined from various remote-sensing observations and how those properties compare to in situ measurements. Following last year's session, we will continue to focus on the 2010 April 3 CME and on more recent events from 2010 August and 2011 February. However, general contributions are invited on any events which have contributed to advance our understanding of CMEs. The questions we plan to address are:

1) How can we best combine different remote-sensing observations to study CME properties and propagation from the Sun to 1 AU?

2) What more can we learn by combining remote-sensing observations and in situ measurements?

3) How do these observations compare with global MHD simulations?

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8. Particle Acceleration and Transport in Flares and their Relation to SEP events
Antoun Daou & David Alexander

Session Description

This session is intended to discuss the inter-relationship between particle acceleration, injection, and transport in solar flares, as well as the possibly correlated SEP events observed at Earth. The basic objective of this session is to refine our physical description of particle kinematics in such events, and explore the possible correlations between solar energetic particle populations in both directions, away from the Sun and into the Chromosphere. Key discussion topics include particle acceleration models, magnetic reconnection, particle transport in flare loops and in the Heliosphere, spatial and temporal evolution of particle spectra, etc.

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9. Coronal Magnetic Fields: What are we learning from CoMP observations?
Joan Burkepile, Steve Tomczyk, Scott McIntosh, David Alexander

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10. What IS a coronal hole?
Phil Judge & Scott McIntosh & David Alexander

Session Description

If you ask this question of a random selection of solar/ heliospheric physicists, a variety of answers will be forthcoming. The cautious ones will ask if this is a "loaded question". While different definitions naturally arise depending on what kinds of observations are favored, it is more disturbing that there is no real concensus as to the physical origin(s) of coronal holes. At stage center is the magnetic field, since the properties of accompanying coronal plasma, whence the name, result from this field. In a Biot-Savart (potential field) sense, one might ask, are there deep-seated electrical current systems which lead to the magnetic fields in coronal holes? But if, as many hold, coronal hole magnetic field is generated and organized by hydromagnetic transport processes at/near the solar surface, then there is no need to invoke deep-seated current systems.

These seemingly different origins of coronal holes are not just a mere curiosity. Some dynamo models rely on the advection of polar coronal hole magnetic field into the solar interior by large meridional flow cells. If the coronal hole field has its origin in currents deep in the solar interior, then the solar dynamo can be entirely an interior process with no need to invoke Babcock-Leighton flux transport.

We hope to explore the physical origins of coronal holes, polar or otherwise, short or long-lived. We hope to find out why, according to the laws of physics, the Sun is obliged to form a "coronal hole" at all. A new understanding of the origins of coronal holes has obvious consequences for their influences throughout the heliosphere.

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11. The Dissipation of Solar Wind Turbulence
John Podesta, Bill Matthaeus, and Greg Howes

Session Description

This session will focus on the following questions:

  • To what extent is the dissipation range of solar wind turbulence dominated by
    Kinetic-Alfven-Wave (KAW) fluctuations, and to what extent can these
    fluctuations be described by gyrokinetic theory?
  • How much of the turbulence cascade power is dissipated on ions and how much
    on electrons?
  • How important is cyclotron damping in the dissipation of solar wind
    turbulence?
  • What is the role of current sheets in the dissipation of solar wind
    turbulence?

Download a more extensive session description in PDF format HERE.

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12. The rise of solar cycle 24: Magnetic fields from the dynamo through the photosphere and corona and connecting to the Heliosphere
Joan Burkepile, Giuliana de Toma, Juan Fontenla, Chuck Smith(UNH)

Session Description

Cycle 24 follows the longest and deepest solar minimum of the Space Age. The first spot of cycle 24 appeared in Jan 2008 but the new cycle showed a very slow start, especially in the southern hemisphere where activity has been lagging by about a year relative to the north. Only in recent months have we seen an increase in the number and complexity of active regions, but overall activity remains low, in spite of the fact that active regions are already emerging at relatively low latitudes. Questions we would like to address in this session are:

What can observations from the solar interior, and in particular the meridional flow and torsional oscillation, tell us about the dynamo action during the early rising phase of cycle 24?

How is magnetic flux emerging in cycle 24 and how does it compare to previous cycles?

What is the significance of the hemispheric asymmetry for the development of the new cycle and for our understanding of the solar dynamo?

Will the two hemispheres reach maximum at different times?

What are the levels and properties of solar activity (e.g. CMEs and flares) in cycle 24 as compared with previous cycles and how has the corona and heliosphere responded?

How have coronal holes, EUV and X-ray fluxes evolved since solar minimum?

What is effect of the weak polar magnetic field on the polar coronal holes and the distribution of open flux in general?

What are the changes in the heliospheric morphology, and plasma and magnetic field properties since solar minimum?

How have these been impacted by current activity properties (e.g. CME and flare rates and energetics)?

What are the open flux levels detected at the Sun and in the heliosphere and how do they compare?

What do current conditions tell us about the location of the alfven critical point (alfven radius)?

How well do PFSS and MHD models reproduce solar and heliospheric conditions in the rising phase?

How can models help us understand solar cycle changes in the heliosphere?

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13. Flare Classification in the Era of Global Coverage of the Sun
A. Vourlidas, C. Cohen

Session Description

Over the last two solar cycles, we have grown accustomed to the GOES Soft X-ray (SXR) characterization of solar flares (the well-known A-X classification). But what is the flare class when there is no SXR instrument to observe it? This is not just a theoretical question. The STEREO in-situ instruments have been recorded SEP events associated with flares from the far side of the Sun. Those solar events are observed very well by the EUV imagers aboard STEREO but there are no SXR measurements. How can we relate those observations to events on the front side or to previous work?

It is clear that we need to develop and agree on a proxy (most likely EUV?) since the 360 deg coverage of the Sun will extend over the rest of Cycle 24 (until 2019 or so). This session is a first attempt to deal with this issue and we invite discussion on the following aspects:

  • Are EUV imaging observations a suitable proxy for the GOES SXR classification?
    • Should we use total irradiance or flux integrated over the event only?
    • Are other quantities (i.e., total emission measure, DEM) better proxies?
  • Preliminary work indicates significant differences in the SXR and EUV light profiles of flares.
    • Why is that?
    • Are certain event types (e.g., large flares, SEP-associated, radio-loud or quiet) better correlated in their EUV/SXR profiles?
  • What quantity (flare SXR class, rise-to-peak, total duration, etc) is more useful for in-situ and other studies?

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