Original title: Solar Magnetic Configuration Control over Radiation Belt Electrons
Ahmad Lalti, Jonathan Rae, Clare Watt, Stephanie Yardley +1 · August 2026
Earth has two concentric rings of particle radiation around it. Its outer radiation belt changes in cycles: every eleven years or so across the solar cycle, across seasons, and every 27 days. Scientists used to think seasonal changes were caused only by local geometry shifting how the solar wind hits Earth's protective magnetic shield. Researchers investigated what drives these changes. They discovered that repeating solar wind coming from solar coronal holes, which are regions with open magnetic fields on the Sun, also drives the seasonal patterns. Specifically, the Alfvénic wave-like behavior of this solar wind boosts the electron flux in the outer belt. This links the Sun's magnetic structure directly to radiation belt changes across many different timescales.
Imagine you are trying to predict when a neighbor will water their garden. You notice it happens every day, every week, and every season. You thought the seasonal pattern was because of the changing angle of sunlight. But then you realize that the same neighbor who waters daily also waters seasonally, because they follow a schedule that repeats at all those intervals. In this paper, the coronal hole solar wind is that neighbor, and its recurring streams drive both the 27-day and seasonal changes in Earth's radiation belts, not the tilt of Earth's axis.
This changes how we predict space weather. Satellite operators and astronauts rely on knowing when radiation belts will intensify. By showing that coronal holes drive seasonal changes too, we can forecast dangerous electron fluxes months ahead instead of reacting after they happen.
The abstract doesn't say. It focuses on the outer radiation belt and coronal hole streams, without addressing other sources of variability or providing a quantitative model.
Ask anything about this paper. Answers come from its abstract, and say so when the abstract doesn't cover your question.
Solar Magnetic Configuration Control over Radiation Belt Electrons — Ahmad Lalti, Jonathan Rae, Clare Watt et al.
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.