An Empirical Model of Vertical Plasma Drift Over the African Sector

Abstract

Daytime vertical E × B drift can be derived from difference of H-component magnetic field measurements (ΔH) using a pair of low-latitude and equatorial latitude magnetometer stations. Knowledge of E × B drift is of utmost importance in space weather-related predictions since it can significantly affect ionospheric density structures and dynamics. For the first time, we developed a quantitative relationship between equatorial electrojet (ΔH) and vertical E × B drift over the African region using magnetometer data and E × B drift observations from the Communication and Navigation Outage Forecasting System (C/NOFS) satellite during local daytime (0700–1800 LT) from 2008 to 2013 when magnetometer data were available. Additionally, we have constructed vertical E × B drift models over the African sector based on C/NOFS vertical E × B drift data and relevant physical and geophysical inputs. Validating using data not included in model development, our model estimated C/NOFS vertical E × B drift with correlation coefficient values of 0.85 and 0.56 during quiet and disturbed conditions, respectively. The daily pattern of the E × B drift velocity is consistent between the developed model based on C/NOFS data and the climatological Scherliess-Fejer model. However, the Scherliess-Fejer model generally overestimated C/NOFS vertical E × B drift (in most cases) with a correlation coefficient of 0.54 during quiet conditions.