The latitudinal variation of geoelectromagnetic disturbances during large (Dst≤−100 nT) geomagnetic storms

Geoelectromagnetic disturbances (GMDs) are an important consequence of space weather that can directly impact many types of terrestrial infrastructure. In this paper, we analyze 30 years of SuperMAG magnetometer data from the range of magnetic latitudes 20°≤λ≤75° to derive characteristic latitudinal profiles for median GMD amplitudes. Based on this data, we obtain a parameterization of these latitudinal profiles of different types of GMDs, providing an analytical fit with Dst‐dependent parameters. We also obtain probabilistic estimates for the magnitudes of “100 year” GMDs, finding that Ḃ = 6.9 (3.60–12.9) nT/s should be expected at 45°≤λ < 50°, exceeding the 5 nT/s threshold for dangerous inductive heating. Key Points Latitudinal distribution of GMDs varies with Dst GMD magnitudes can vary strongly at fixed latitude Statistical likelihood of large GMDs is nearly independent of storm strength at high latitudes