A Sign-Reversing Lunar-Solar Declination Gate in Ground and Swarm Magnetic Variability

This archive contains the reproducible data-and-code package for "A Sign-Reversing Lunar–Solar Declination Gate in Ground and Swarm Magnetic Variability." This study asks whether the previously reported lunar–solar declination gate on low–mid-latitude night-sector ground magnetic variability is stationary. Under the locked model of the prior studies, applied to a fixed nineteen-station long-record INTERMAGNET family, the era-evaluated gate effect reverses sign twice across 2000–2024 (weakly positive, then increasingly negative to a 2017–2019 extreme, then positive again), with every era separated from a per-station lunar circular-shift placebo and replicated across two independent panel halves. An out-of-sample test on 2025–2026 — data acquired after all covariate panels were frozen, spanning the 18.6-yr major lunar standstill at which the lunar declination envelope peaks — finds the positive gate at its strongest era value in the 26-year record, with the standstill year 2025 alone at more than three times the 2020–2024 era mean, leave-one-station-out unanimous, hemisphere-symmetric, and strengthened by storm removal. The same era sequence appears in the night-side magnetic residuals of the instrumentally independent Swarm constellation, consistently across its three (correlated) spacecraft, and the pre-registered spaceborne standstill-versus-trough contrast exceeds every replicate of a date-coherent placebo (p = 0.003). The sequence's phase is consistent with the lunar nodal cycle without tuning; because fewer than two nodal cycles have been observed, the paper closes by registering the 2026–2030 observations that discriminate a nodal oscillation from continued phase rotation, to be adjudicated under the same locked analysis. The archive includes the manuscript (docx and pdf), runnable numbered demos that reproduce every main numerical claim from the bundled derived tables alone (station-day ground outcome table 2000–2026, collapsed Swarm daily residual cells 2014–2026, forward-window geometry and F10.7 tables with calibration checks), the frozen result tables with seeds and placebo exceedance counts, figures, the native Word equation bank used by the manuscript build, the analysis scripts of record, and reference lists. Raw INTERMAGNET one-minute and Swarm 10-second provider data are not redistributed; derived tables and retrieval scripts are provided under the providers' terms, with acknowledgments to the observatory operators, INTERMAGNET, ESA/Swarm and the VirES service, NASA/GSFC OMNIWeb, and Natural Resources Canada. This record is the third archive of a series. Paper 1 (record 10.5281/zenodo.21082993) reported the original F10.7-conditioned lunar-declination gate and is accepted at JGR: Space Physics. Paper 2 (record 10.5281/zenodo.21175748) localized the gate to the transfer of solar-wind coupling into the ground vector and is under review. The present record adds the temporal dimension: the gate's sign is epoch-dependent, and its 2025 standstill behavior was confirmed out of sample. The prior archives are linked under Related works.