🌐 Geodetic Codex V9.2

🔍 Objectives

• Quantify relationships between orbital cycles and ice-volume proxies.
• Characterize lead–lag structures between orbital forcing and cryosphere response.
• Identify pulse sequences that correlate with rift initiation and uplift counterweights.

🧠 Key Concepts

• Precession (≈19–23 kyr) – seasonal/hemispheric insolation swings; often drives monsoon–ice feedbacks.
• Obliquity (≈41 kyr) – high-latitude summer insolation; strong control on ice-sheet mass balance.
• Eccentricity (≈100/405 kyr) – amplitude modulator for precession; tied to late-Pleistocene pacing.
• Amplifiers – albedo, ocean heat transport, and freshwater routing that sharpen deglaciation pulses.

📦 Data Inputs (placeholders)

• Orbital solutions: Laskar La2004/La2010 (eccentricity, obliquity, precession indices).
• Ice-volume / δ¹⁸O stacks: LR04, benthic stacks; ice cores (EPICA, GISP2/NEEM) for high-res sections.
• Deglacial events: MWP-1A, MWP-1B, Younger Dryas termination markers.
• Codex layer: Rift–Cryosphere Timeline (epoch, cap dominance, anomaly pairings).

Replace with actual repository links/DOIs when you stage the analysis notebooks.

🧪 Methods (analysis plan)

1. Spectral diagnostics: multitaper/FFT on ice proxies; verify 23/41/100/405 kyr bands.
2. Cross-correlation: orbital indices vs. ice proxies to estimate lead–lag (regional & global).
3. Event alignment: align meltwater pulses to orbital phase; annotate cap dominance (N vs S).
4. Coupling to rifts: join pulse windows to Codex rift entries; test for clustering near anomaly pairings.
5. Robustness: bootstrap confidence intervals; shuffle tests against null (phase-scrambled indices).

🗺️ Figures (placeholders)

• Phase wheels: orbital phase → meltwater pulse timing → rift activation markers.
• Hemispheric pie/bar: cap dominance distribution per orbital band.
• Global map: pulses layered on anomaly pairings (from V3/V8 geodesic products).

✅ Outputs

• Lead–lag table for (eccentricity/obliquity/precession) vs. cryosphere response with CIs.
• Tagged pulse intervals usable as features for V9.3–V9.5 modeling.
• Reproducible notebook linking orbital pacing to Codex rift entries.

📚 References (to stage)

• Laskar et al., orbital solutions La2004/La2010 (obliquity/eccentricity/precession indices).
• LR04 benthic stack; EPICA Dome C; GISP2/NEEM ice-core chronologies.
• Deglacial pulse literature (MWP-1A/1B timing constraints).