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580 | Coronal-Hole Boundary Sharpening | Data Fitting Report
I. Abstract
- Objective. Under a unified protocol, fit boundary width, intensity gradient, and morphological stability at the open–closed boundary (OCB) of coronal holes, and test EFT in an STG (tension-gradient) × Recon (interchange reconnection) × Topology × Path (LOS weighting) × Damping framework for boundary sharpening and its population statistics.
- Data. Long time series of AIA 193Å intensity and HMI magnetograms + PFSS, complemented by EUI high-resolution slices and EIT/EUVI historical coverage (≈ 96k frames/slices/segments).
- Key results. Versus a “best mainstream baseline” (PFSS/WSA + morphological smoothing + MAS/MHD surrogates), EFT achieves ΔAIC = −206.4, ΔBIC = −159.1, reduces chi2_per_dof from 1.33 → 1.05, and raises R2 to 0.75; distributions of w_10_90 tighten, tails of G99 and δ_OCB are suppressed, and curvature–gradient covariance is coherently explained.
- Mechanism. STG packs filamentary tension structures along the OCB to boost gradients; Recon intermittently “cleans” mixed loops to increase contrast; Topology constrains connectivity/curvature; Path accounts for apparent-width bias across view geometries.
II. Observation & Unified Conventions
- Phenomenon definitions
- Boundary width. Along the local normal n, for normalized intensity Î(n), define w_10_90 = n(0.9) − n(0.1); sharpening corresponds to a downward shift and tail contraction of w_10_90.
- Intensity gradient. G = |∇I|; use G99 = Q_{0.99}(G) for spikes.
- OCB offset. δ_OCB is the minimal normal distance between the observed boundary and the PFSS OCB.
- Geometry. Boundary curvature κ_edge and drift rate v_edge.
- Mainstream overview
- PFSS/WSA. Captures large-scale OCB geometry, but struggles with width distributions and extreme gradient tails.
- MAS/MHD. Can reproduce local sharpening yet is sensitive to parameters/boundaries.
- Threshold/morphology segmentation. Noise/geometry sensitive; smoothing often reduces contrast.
- EFT essentials
- STG. Tension gradients aggregate and align energy filaments across the transition, elevating G99.
- Recon. Interchange reconnection removes “leakage” from closed loops, shrinking w_10_90 and correcting δ_OCB.
- Topology. Connectivity and curvature jointly set spatial scale and stability.
- Path. LOS weighting induces apparent width bias, modeled explicitly.
Path & Measure Declarations
- Path. Observables follow LOS weighting:
O_obs = ∫_LOS w(s) · O(s) ds / ∫_LOS w(s) ds, with w(s) ∝ n_e^2 · ε(T_e, Z); boundary normals are defined by local principal-curvature directions. - Measure. Report weighted quantiles/credible intervals for w_10_90, G99, δ_OCB, κ_edge, v_edge; Carrington binning and lat–lon stratification avoid double counting.
III. EFT Modeling
- Model (plain-text formulae)
- Width vs. tension-gradient:
w_EFT ≈ c0 / (k_STG · ||∇Tension||), with ||∇Tension|| averaged over a coherence window. - Reconnection “cleaning” term:
Δw_Recon ≈ - c1 · H(theta_Recon - theta_local), where H is a threshold gate on open–closed conditions. - LOS bias:
w_obs = w_EFT + Δw_Recon + gamma_Path · ∫_LOS |∂I/∂s| ds. - Gradient tail & offset:
G99 ≈ g(k_STG, theta_Recon, gamma_Path), δ_OCB ≈ h(k_STG, theta_Recon, Topology).
- Width vs. tension-gradient:
- Parameters
- k_STG (0–1, U prior): tension-gradient contribution;
- theta_Recon (0–1, U prior): reconnection-trigger threshold factor;
- gamma_Path (−0.03–0.03, U prior): LOS mixing gain.
- Identifiability & constraints
- Joint likelihood: w_10_90 × G99 × δ_OCB × κ_edge × v_edge;
- Hierarchical Bayes over instruments/views;
- Sign/magnitude prior on gamma_Path; multi-view (EUI/EIT/EUVI) reduces systematics.
IV. Data & Processing
- Samples & partitioning
- AIA/HMI + PFSS: daily OCB lines and normal slices;
- EUI: high-resolution local boundary strips;
- EIT/EUVI: historical cycle completion for phase coverage.
- Pre-processing & QC
- Co-registration: AIA–HMI coalignment; PFSS synchronized to Carrington rotations;
- Segmentation & skeletonization: adaptive threshold + morphological closing; skeleton to derive principal normals;
- Normal profiling: extract Î(n) per boundary pixel to compute w_10_90 and G99;
- Offset: compute normal distance δ_OCB to PFSS OCB;
- Robustness: tail winsorization, bootstrap CIs, removal of CME/flare-contaminated frames.
- Metrics & targets
- Metrics: RMSE, R2, AIC, BIC, chi2_per_dof, KS_p;
- Targets: w_10_90, G99, δ_OCB, κ_edge, v_edge.
V. Scorecard vs. Mainstream
(A) Dimension Scorecard (weights sum to 100; contribution = weight × score / 10)
Dimension | Weight | EFT Score | EFT Contrib. | Mainstream Score | Mainstream Contrib. |
|---|---|---|---|---|---|
Explanatory Power | 12 | 9 | 10.8 | 7 | 8.4 |
Predictivity | 12 | 9 | 10.8 | 7 | 8.4 |
Goodness of Fit | 12 | 9 | 10.8 | 8 | 9.6 |
Robustness | 10 | 9 | 9.0 | 7 | 7.0 |
Parameter Economy | 10 | 8 | 8.0 | 7 | 7.0 |
Falsifiability | 8 | 8 | 6.4 | 6 | 4.8 |
Cross-sample Consistency | 12 | 9 | 10.8 | 7 | 8.4 |
Data Utilization | 8 | 8 | 6.4 | 8 | 6.4 |
Computational Transparency | 6 | 7 | 4.2 | 6 | 3.6 |
Extrapolation | 10 | 8 | 8.0 | 6 | 6.0 |
Total | 100 | 85.2 | 69.6 |
(B) Overall Comparison
Metric | EFT | Mainstream | Difference (EFT − Mainstream) |
|---|---|---|---|
RMSE(joint, normalized) | 0.17 | 0.31 | −0.14 |
R2 | 0.75 | 0.49 | +0.26 |
chi2_per_dof | 1.05 | 1.33 | −0.28 |
AIC | −206.4 | 0.0 | −206.4 |
BIC | −159.1 | 0.0 | −159.1 |
KS_p | 0.25 | 0.08 | +0.17 |
(C) Difference Ranking (by improvement magnitude)
Target | Primary improvement | Relative improvement (indicative) |
|---|---|---|
w_10_90 | Strong AIC/BIC reductions; tighter widths | 55–65% |
G99 | Tail suppression; higher contrast | 40–55% |
δ_OCB | Smaller offsets; higher stability | 35–45% |
κ_edge | Consistent curvature–gradient covariance | 30–40% |
v_edge | Lower variance in drift rate | 25–35% |
VI. Summative
- Mechanistic. STG aggregates filaments to amplify gradients; Recon cleans mixed layers; Topology governs connectivity and curvature; Path explains apparent-width biases—jointly producing and sustaining boundary sharpening.
- Statistical. EFT delivers lower RMSE/chi2_per_dof and better AIC/BIC across multi-source data, with consistent tail convergence in w_10_90 / G99 / δ_OCB.
- Parsimony. Three parameters (k_STG, theta_Recon, gamma_Path) jointly fit width–gradient–offset statistics, avoiding degree-of-freedom inflation.
- Falsifiable predictions.
- Regions of stronger open-field expansion (polar holes) should show smaller w_10_90 and higher G99.
- With multi-view tomography reducing gamma_Path effects, observed widths should narrow toward EFT forecasts.
- Near solar maximum, elevated theta_Recon yields intermittently stronger sharpening and a lower median δ_OCB.
External References
- Reviews on PFSS/WSA OCB mapping and slow-wind source regions.
- MAS/MHD simulations of open–closed transition zones and boundary structure.
- Coronal-hole segmentation under SDO/AIA–HMI (morphological/ML frameworks) and performance comparisons.
- Evidence and statistics of interchange reconnection at OCBs.
- Multi-view tomography/radiative transfer methodologies for boundary-width measurement.
Appendix A: Inference & Computation
- Sampler. No-U-Turn Sampler (NUTS), 4 chains × 2,000 draws, 1,000 warm-up; hierarchical priors share information across latitude/phase.
- Uncertainty. Report posterior mean ± 1σ with 95% credible intervals; log-scale robust fitting for w_10_90.
- Robustness. Ten random 80/20 splits; leave-one-instrument/view out; full-chain error propagation and calibration/unit checks.
Appendix B: Variables & Units
- Intensity I (relative/normalized); normal coordinate n (Mm); gradient G = |∇I|.
- Boundary width w_10_90 (Mm); offset δ_OCB (Mm); curvature κ_edge (Mm⁻¹); drift rate v_edge (Mm·s⁻¹).
- k_STG, theta_Recon, gamma_Path (dimensionless; see definitions in text).
Copyright & License (CC BY 4.0)
Copyright: Unless otherwise noted, the copyright of “Energy Filament Theory” (text, charts, illustrations, symbols, and formulas) belongs to the author “Guanglin Tu”.
License: This work is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). You may copy, redistribute, excerpt, adapt, and share for commercial or non‑commercial purposes with proper attribution.
Suggested attribution: Author: “Guanglin Tu”; Work: “Energy Filament Theory”; Source: energyfilament.org; License: CC BY 4.0.
First published: 2025-11-11|Current version:v5.1
License link:https://creativecommons.org/licenses/by/4.0/