The Effect of South Atlantic Anomaly on Ring Current Electron Dynamics

The South Atlantic Anomaly (SAA) signicantly inuences particle dynamics and loss within the inner magnetosphere. Yet many inner magnetosphere models neglect the hemispheric magnetic‐eld asymmetry, leaving the impact of the SAA on ring current particles and the energy dependence of precipitation poorly constrained. Using the Storm‐Time Ring Current Model (STRIM), which incorporates the realistic SAA magnetic eld minimum, we simulate a storm event to quantify the SAA's eect on electron precipitation. Results reveal substantially enhanced electron precipitation ux near the SAA compared to other regions at L = 2–4. Furthermore, wave‐particle interactions signicantly accelerate the decay of high‐energy electrons (tens to hundreds of keV) within the SAA, driving increased precipitation into the ionosphere. Comparisons with in‐situ satellite observations demonstrate that simulations incorporating both the SAA eect and wave‐particle interactions capture the observed intensity and temporal variations of electron precipitation much more accurately than simulations that omit the SAA‐related magnetic‐eld asymmetry. This study highlights the necessity of incorporating realistic SAA eects and wave interactions in ring current models for a better interpretation of electron dynamics and precipitation asymmetries.