WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

WG2 Topical Sessions

Origin and Evolution of the Solar Wind (Wed AM)

Magnetic Data Input into Global Models (Thu PM)

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

WG1/2 Session: Origin and Evolution of the Solar Wind

Invited Talks:

1. Phil Isenberg (UNH): “Kinetic Mechanisms for Generation of the Fast Solar Wind”

2. Uri Feldman (NRL): “The Source of the Solar Wind in Quiet and Coronal Hole Regions”

3. Scott McIntosh (SWRI): “Magneto–Convection Driven Spicules: Fast Solar Wind Origins and the Potential Impact on CME Propagation”

4. Tayeb Aiouaz (HAO): “The Supergranular Magnetic Network, its Expansion and Effects through the Solar Atmosphere”

Contributed Talk:

1. Jason Gilbert (UM): “Applications of the Diffusive Equilibrium Mapping Technique”

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Phil Isenberg (UNH): “Kinetic Mechanisms for Generation of the

Fast Solar Wind”Talk summary: Fast SW is produced by strong perpendicular ion heating (at

2–6 RS).

Specific heating mechanisms must be modeled kinetically to determine their feasibility.

Detailed heating mechanism is necessary to correctly model the microphysics in global simulations of solar wind and CME behavior.

Recent work has indicated the possibility of a parallel turbulent cascade to resonant frequencies.

Some possible kinetic mechanisms for ion heating include:Cyclotron resonant interaction of ions with oblique waves.

Proton heating by electrostatic waves – generated from electron beams and processed by ion cyclotron resonant scattering.

Preferential perpendicular heating of heavy ions by 2nd order Fermi acceleration.

Alpha particles are a major concern and will be a stringent test to any theoretical model!

Future UVCS observations will be important to constrain the models.

Solar Probe may also provide important in situ observations near the Sun to test the various models.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Uri Feldman (NRL): “The Source of the Solar Wind in Quiet and Coronal Hole

Regions”

Talk summary: SW composition and photospheric compositions are not always

the same. FIP Bias (coronal abundance / photospheric abundance) can be

used to distinguish between fast and slow SW:FIP Bias ~4 (Mg, Si, Fe) in slow SW; same for quiet Sun.

FIP Bias ~1 in fast SW.

Elemental settling in solar coronaFe is depleted in height in the corona relative to Mg and Si.

Recent theories by Fisk and colleagues may explain this behavior.

SW originates at ~106 K (solar upper atmosphere):Slow SW originates from the quiet Sun corona close to solar surface.

Fast SW is associated with coronal hole regions.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Uri Feldman (NRL): “The Source of the Solar Wind in Quiet and Coronal Hole

Regions”

Sun at 106 K Sun at 105 K

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Scott McIntosh (SWRI): “Magneto–Convection Driven Spicules: Fast Solar Wind Origins and the Potential Impact

on CME Propagation”

From Wang (1998) & Priest et al. (2002)

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Scott McIntosh (SWRI): “Magneto–Convection Driven Spicules: Fast Solar Wind Origins and the Potential Impact

on CME Propagation”Talk Summary: SUMER results have provoked a simple analysis of long-

duration (rare) SOHO/EIT 304Å data to test this hypothesis. Study showed that observed spectroscopic, imaging, and wave

signatures are all consistent with the ubiquitous driving of solar plasma by magneto-convection-driven reconnection.

The relentless emergence, advection, and eventual destruction of magnetic flux on supergranular scales is responsible for mass loading, heating and initial acceleration of plasma at the base of solar corona.

Local magnetic field conditions control the rate and scale of the energy release.

Global magnetic field topology controls how the energy is released and utilized by plasma: plasma heating versus bulk motions.

SW initiation and atmosphere plasma heating can be performed with one single process, where spicules are the basic building blocks of this process.

This model can explain a number of solar phenomena named differently because they are observed in different wavelengths.

SUMER Ne VIII

Intensity/Doppler Comparison

Quiet Sun: Bulk blue-shift (4% of pixels) located at network “vertices.”No apparent correlation of blue-shift with rest of network cell pattern.Coronal Hole:LOTS more blue-shifted regions (22% of pixels).Considerable drop (40%) in emission.Still no apparent correlation of blue-shift with network cell pattern, but appear mostly on interior-side of cell boundaries.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Tayeb Aiouaz (HAO): “The Supergranular Magnetic Network, its Expansion and Effects through the

Solar Atmosphere”Talk Summary: Unipolar vs. mixed

polarities:At low heights network loops affect expansion.

At higher heights cases converge.

BG vs. no BG case:Reduced amount of network flux.

Internetwork field does reach the corona.

Reconnection at network boundaries.

Network vs. single-funnel expansion:

“Single-funnel” like network is obsolete.

There is variety of structures (open & closed) in network.

Work in progress: 3D MHD simulations of QS.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Summary & Plans for Next SHINE

Modelers need additional observations to evaluate the significance of the existing mechanisms for the generation of fast SW (e.g., by turbulent heating, cyclotron resonant heating, etc.)?

Some observations, however, are unaccounted for in the models, or remain unexplained.

How do we fill the existing gaps to make further progress on this topic?

Another big questions is: Is SHINE community interested in having the same topical

session at the next meeting? If so, what should we focus on?

Origin of fast solar wind again?

Discuss the messy slow solar wind?

Ideas are always welcome!

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

WG2 Session: Magnetic Data Input into Global Models

Invited Talks:

1. Luca Bertello (UCLA): “Mt. Wilson Magnetic Field Observations: Methods and Calibration”

2. Leif Svalgaard (ETK): “How Good/Bad Are the Inner Boundary Conditions for Heliospheric Solar Wind Modeling?”

3. Carl Henney (NSO): “SOLIS-VSM Magnetic Synoptic Maps”

4. Yang Liu (Stanford): “Synoptic Maps of Magnetic Field from MDI and WSO Magnetograms”

5. Igor Sokolov (UM): “Semi-Empirical MHD Modeling of the Solar Corona and Solar Wind”

Contributed Slides:

1. K.D. Leka (CoRA): “With Two Hands on IVM Data”

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Luca Bertello (UCLA): “Mt. Wilson Magnetic Field Observations: Methods

and Calibration”

Talk summary: Calibration of observables,

center-to-limb correction, and saturation factor correction.

Observations in Fe I 5233Å provide reference magnetic field measurements unaffected by saturation effects.

Magnetic fields are compared point by point to get a saturation factor.

MWO data are used to fix the “zero point” in the calibration of MDI data.

There is no simple scaling factor, but a mask that needs to be applied.

Proper orientation of MDI m-gram is important.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Leif Svalgaard (ETK): “How Good/Bad Are the Inner Boundary Conditions for Heliospheric Solar Wind Modeling?”

Talk summary: No matter how sophisticated

a physics-based SW model is, it is no better than the quality of the magnetic map used.

WSO and SOLIS data show that the observed B field behaves as a simple projection of a radial field.

So are MWO data before the hardware upgrade in 1982.

To get the true magnetic flux, MWO data (collected after 1982) should be multiplied by:

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Carl Henney (NSO): “SOLIS-VSM Magnetic Synoptic Maps”

Talk summary: Transition from KPVT to

SOLIS.KPVT renamed to KP SOLIS Tower.KPVT & SOLIS-VSM have similar characteristics.

Beta-testers are needed to input data into their models!

SOLIS-VSM provides vector B-field measurements on the whole Sun.

SOLIS-VSM has detected SOLIS-VSM has detected several new cycle bipolar several new cycle bipolar magnetic regions starting in magnetic regions starting in June 2006!June 2006!

VSN status summary:VSN status summary:Transition from development phase to operations phase.Operating 7 day/week. Some VSM data processed in near real-time.Started VSM requested observing.

15 June 2006

(also observed

16th)

5 July 2006

(also observed

4th)

23 July 2006

(also observed

22nd)

New cycle

Old cycle

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Yang Liu (Stanford): “Synoptic Maps of Magnetic Field from MDI and WSO

Magnetograms”

Talk summary: Individual MDI magnetograms need:

Offset correction; andRescaling.

Remapping of individual MDI magnetograms yields a synoptic map.

Correction for differential rotation is needed.Polar field correction is needed (7 techniques exist, but 2 work best).

Modelers have began using MDI data in their models. How about WSO data?

High accuracy.Excellent determination of the magnetic “zero level.”Consistent 30-year time-series of low-resolution, large-scale B-field measurement without any significant instrumentation modification.

Community support needed to continue WSO operation!!!

16

WSO Data Applications

From Arge (2005)

PFSS

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Igor Sokolov (UM): “Semi-Empirical MHD Modeling of the Solar Corona and Solar

Wind”Talk summary: Global MHD model is driven by a

full-disk MDI magnetogram. Using the Bernoulli integral,

the semi-empirical values of the SW speed at 1 AU are related to the boundary condition for the “turbulent energy density” at the solar surface.

SW speed computed from WSA model.To bridge from this boundary condition to the SW model in the solar corona, the varied polytropic index is used.

Modeled SW parameters at 1AU in good overall agreement with observations.

Modeled IMF is 4 times weaker though.Scaling factor for MDI magnetogram needs to be applied.

WG2 Sessions

SHINE Workshop, July 31–August 4, 2006

Summary & Plans for Next SHINE

We have learned about the variety of existing magnetic data that are available to the community (MWO, SOLIS, MDI, IVM, WSO, etc.)

We have learned how grapes are collected from the vineyard, processed, fermented, bottled, and delivered to the store to satisfy our fine taste.

We also learned about the quality control. Now modelers are asked to do “wine tasting” and report on

the variations in taste. Observers are asked to supply cheese and crackers. This means:

Pick a Carrington Rotation for which magnetic data exists from various observatories, and are of good quality.Other data inputs are welcome (e.g., density maps).Use these data to drive your simulations.Report on the structure of the SW and IMF at 1AU, or at other locations for which in situ data exist.

Results of such investigation are very important. Will modelers take the challenge? Will observers provide cheese and crackers?