Time dependence of multiple geomagnetic surface intensity minima

We present a topological algorithm designed to calculate the time-dependent areas and centers of complex geomagnetic field configurations characterized by multiple local surface intensity minima enclosed within a common threshold value. The algorithm is based on the identification of saddle points, which allows the subdivision of the South Atlantic Anomaly (SAA) into distinct sub-regions associated with individual local minima. All codes required to reproduce the results presented in Yue et al. (submitted to Journal of Geophysical Research: Solid Earth) are provided. The functions used to compute the sub-areas are included in the corresponding code files. The geomagnetic field models referenced in this work include the CHAOS-8.2 model (Kloss et al., 2025), the COV-OBS.x2 model (Huder et al., 2020), and the HistKalmag model (Schanner et al., 2023). The associated Gauss coefficients are obtained from the following sources: CHAOS-8.2: https://www.spacecenter.dk/files/magnetic-models/CHAOS-8/archive.html COV-OBS.x2: https://www.spacecenter.dk/files/magnetic-models/COV-OBSx2/ HistKalmag: https://ionocovar.agnld.uni-potsdam.de/Kalmag/Histo/ For further data sharing or inquiries, please contact: ychyue@iggcas.ac.cn.