Estimating the Daytime Vertical E × B Drift From Magnetometer and C/NOFS Measurements and Comparison With Empirical Models Over the East African Sector

Abstract

AbstractThis paper introduces a new approach of estimating the daytime horizontal geomagnetic field (ΔH)‐induced variations of vertical E × B drift velocity and evaluates its performance using Communication/Navigation Outage Forecasting Systems (C/NOFS) over the East African sector. H field at AAE (Addis Ababa magnetometer station) and ETHI (Adigrat magnetometer station in Ethiopia) and their immediate difference alongside with C/NOFS E × B drift were used for periodic polynomial fitting (PPF) a periodic basis. Knowledge of E × B drift is of utmost importance in space weather‐related predictions since it can significantly affect ionospheric density structures and dynamics. The periodic fitting illustrates better agreement with C/NOFS observation during 16:00–19:00 LT than 10:00–16:00 LT whose root‐mean‐square error (RMSE) increased from 9.2 to 12.67 m/s, respectively. Comparison of PPF, recent regional E × B model made by Dubazane and Habarulema (2018, https://doi.org/10.1029/2018SW001820) (E × BDub) and E × BIRI (vertical E × B estimates of International Reference Ionosphere [IRI]) was carried out using C/NOFS observation. Independent model validation shows that C/NOFS E × B values are closer to PPF estimates than E × BDub and E × BIRI over the region. Besides, the least squares model with physical inputs including local time (LT), day of the year (DOY), extreme ultraviolet (EUV) flux, and ΔH provides lowest RMSEs of about 5.36 and 7.41 m/s using a method of neural networking during low solar activity (LSA) and high solar activity (HSA), respectively.