solar eruption onset: where does the action begin?

A. Sterling, Feb 03 1

Solar Eruption Onset: Where Does the Action Begin?

Alphonse C. Sterling

UAT/NASA/MSFC/NSSTC/ISAS

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Introduction• Eruptions on the Sun involve the sudden release of large

amounts of energy. • Where does the main energy release occur, and where are

the key regions that are involved? Two possibilities:– Core region only, e.g., Moore & LaBonte, Moore et al. (“tether

cutting); Chen; etc.– Far from the core also: Uchida (“quadruple model”); Antiochos

et al. (“Breakout model”).

• Objective: Compare Yohkoh and SOHO observations with predictions from Tether Cutting and Breakout models.

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Two Theories:• Tether cutting. Moore & Labonte (1980); Sturrock (1989);

Moore et al. (1997; 2001). Fundamentally bipolar. Energy release via reconnection deep inside the “core

field.”

• Breakout model. Antiochos (1998); Antiochos et al. (1999).

Fundamentally multi-polar, with bipole core fields and restraining overlying fields.

Earliest energy release via slow reconnection at interface.

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(Moore et al. 2001)

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Antiochoset al. (1999)

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Data: A Slow, Large-Filament Eruption

• Large-scale, quiet region eruption.

• Slow evolution (weak fields); can observe eruption in “slow motion.”

• Test theories using timing studies.

• Sterling, Moore, & Thompson (2001).

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A. Sterling, Feb 03 9Sterling, Moore, Thompson (2001)

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Sterling, Moore, Thompson (2001)

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What about Breakout? Look for earlyfar-away activity with dimming images.

No evidence for tether cutting prior to filament launch (at least, very low EM in EUV).

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Summary for This Event

• Quadruple, or quadrupole, structure

• Tether Cutting seems to not work.

• Might be consistent with Breakout.

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General Summary (Solar-B)

• In at least some cases, the action begins far away from core.

• Some observations with pointing offset from flare center could be important for understanding eruption onset.