Magnetic Topology and the CoronaHeliosphere Connection - PowerPoint PPT Presentation
Title:
Magnetic Topology and the CoronaHeliosphere Connection
Description:
Field defines smooth volume mapping, except at separatrix lines/points, even if J = 0. ... opening must extend to separatrix. Topology of Fully 3D Breakout ... – PowerPoint PPT presentation
Number of Views:34
Avg rating:3.0/5.0
Title: Magnetic Topology and the CoronaHeliosphere Connection
1
Magnetic Topology and the Corona-Heliosphere
Connection
Spiro K. Antiochos
Code 7675, Naval Research Lab, Washington DC
20375 antiochos_at_nrl.navy.mil
- Background
- Frozen-in flux (tD L2 / ? gtgt tL ) implies that
magnetic topology constrains plasma structure and
dynamics - Determines how photo/corona connects to
heliosphere - Importance
- Restricts possible topology of coronal holes (CH)
- Insight into 3D CME models breakout
- Predictions for LWS and especially SDO
2
Basic Assumptions
- Continuous polarity distribution at photosphere
- Structure given by neutral line geometry
- Neglect small-scale dipoles/structure
- No current singularities in closed field region
- Basically assuming quasi-static equilibrium
- Extension of source-surface model
- Field-line mapping smooth except at separatrices
3
- Canonical coronal magnetic topology
- Two large-scale neutral lines on photosphere
- Three separatix curves and two points on
photosphere - Field defines smooth volume mapping, except at
separatrix lines/points, even if J 0.
Field line equations dx/ds Bx/B dy/ds
By/B dz/ds Bz/B Singularity e.g., splitting,
only if, Bx, By, or Bz discontinuous or B
vanishes
4
Conjecture One CH per Polarity Region
- Consider simple polarity region with one CH
- Consider annulus of closed flux surrounding CH
- Cannot map to adjacent area,
- Requires line splitting, current singularity in
closed field region
5
- Must map to surrounding annulus
- But then, second CH would split closed lines
6
- Consider embedded polarity region
- If region closed, annulus maps over the top
- If region contains coronal hole?
- Problem with both CH and spine
7
- If polarity regions embedded, CHs are embedded
- Opening of CH in embedded region drives external
CH - Creates coronal hole corridor
- CH in embedded region must extend to spine CMEs?
8
- Interaction of AR with CH
- Begin with AR fully in closed region
- Apply photo motion that moves AR into CH
- Interchange reconnection opens spine
- Creates open field corridor surrounding spot
(movie)
9
- 3D interaction of active region and coronal hole
- Reconnection opens field surrounding AR
10
Topology of 3D Breakout Eruption
- Any long-lived opening must extend to separatrix
11
Topology of Fully 3D Breakout
- Minimize required energy by rearranging
separatrices (reconnection)
12
Global Plus Low-Latitude AR
? 20o
- AR field embedded in closed field region
- Topology of coronal hole essentially unchanged
13
Topology of Low-Latitude AR
? 20o
- Negative polarity AR flux encased by S-surface
(fan) and ?-lines (spine) - 3D null point in corona
- S-surface greatly distorted due to flux
distribution at photosphere
14
CONCLUSIONS
- Topology provides strong constraints on
corona-heliosphere connection - One CH per polarity region CH corridors
- Embedded polarities imply embedded CHs
- Topology plays critical role in 3D eruptions
- Mechanism underlying breakout
- Predicts spine movement, dimming areas,
- Fascinating field for Theory/SDO studies
Recommended
CrystalGraphics Presentations
