A pre-computed calendar of geophysical activity waves compared with the Sun, ocean, atmosphere and natural hazards, 2017–2026

We test a calendar of waves of increased geophysical activity that is computed from the calendar alone, following the “Geophysical Resonance” methodology of A. Zakharov. The waves last 2.5 to 5.5 months; for 2017–2026, sixteen waves (W1–W16) with start and end dates are available. We compare them with independent observations of the Sun, the geomagnetic field, the ocean, the atmosphere and natural hazards, and test every relationship against calendars in which the waves are randomly shifted by 30 to 180 days. Findings: at wave start the solar wind is faster than in the following inter-wave phase (−0.39 σ, p = 0.004; 14 of 16 waves), geomagnetic activity is higher, and more Forbush decreases of cosmic rays occur in the first third of a wave (10 versus 4.2 expected, p = 0.003). After wave end the Southern Oscillation Index rises (13 of 16 waves, p = 0.009); in the last third of a wave the North Atlantic Oscillation is positive. In Central Europe there is more lightning (+44 %, p = 0.003) and more radar-detected heavy rainfall (p = 0.0001) 30 to 10 days before wave start, and more vegetation fires after wave ends in the cold season. These three regional findings persist when the wave boundaries are shifted by up to five days. Globally the lightning pattern is regional: in a grid analysis more areas than expected show more lightning, most clearly Europe, eastern Australia and eastern China, while other areas show less. The eleven climate drivers taken together do not predict the wave state; the calendar therefore carries information not contained in them. The analysis is exploratory. The main relationships are pre-registered and are tested at each new wave, starting with W17.