Climatology + Perturbation Approach for Modelling Equatorial Vertical ExB Drift Velocity Using Ground-Based Magnetometers

The equatorial vertical ExB plasma drift velocity is one of the primary drivers of the equatorial ionisation anomaly during both quiet and disturbed geomagnetic conditions.Currently, the only incoherent scatter radar (ISR) capable of measuring F-region plasma drifts at the equator is located at the Jicamarca Radio Observatory, Peru.A technique first developed by [1], then refined by [2], has enabled the F-region vertical plasma drifts to be inferred from a pair of appropriately located ground-based magnetometers and a modelled relationship between the magnetometer and ISR drift velocity measurements.In this paper we describe a new approach to this technique which makes use of larger datasets, predicts the perturbation away from the climatological vertical ExB drift velocity modelled by [3], and is valid in any longitude sector and under any geomagnetic condition.