Geomagnetic Storm Impacts on the Lower Atmosphere: Connections Between the Hale Cycle, Ap, Kp and ENSO

The Sun provides the energy required to sustain life on Earth and drive our planet’s atmosphere. However, establishing a solid physical connection between solar and tropospheric variability has posed a considerable challenge across the spectrum of Earth-system science. Over the past few years a new picture to describe solar variability has developed, based on observing, understanding and tracing the progression, interaction and intrinsic variability of the magnetized activity bands that belong to the Sun’s 22-year magnetic activity cycle. A solar cycle’s fiducial clock does not run from the canonical min or max, instead resetting when all old cycle polarity magnetic flux is cancelled at the equator, an event dubbed the “termination” of that solar cycle, or terminator.

In Phoenix, at the 32nd CVC, we demonstrated that solar cycle Terminators and major oceanic oscillations (primarily the El Niño-Southern Oscillation, ENSO, and the North Atlantic Oscillation, NAO) are correlated, going back to the 1960s (end of solar cycle 19), and that we predicted the end of solar cycle 24, and the associated swing to La Niña-like conditions to occur in 2020.

La Niña did indeed begin in mid-2020, as we reported at the Virtual 34th CVC, and endured into 2023 as a rare “triple dip” event, but some of the solar predictions made did not occur until late 2021. Here we examine what went right, what went wrong, the correlations between El Niño, La Niña and geomagnetic activity indices, and what might be expected for the general trends of large-scale global climate in the next decade. The headline prediction is that 2023-24 will not see a "Super El Niño"; rather we will argue that 2025-26, after solar maximum is more likely for the next big event.