A New Model for Ionospheric Total Electron Content: Longitudinal Variations in Model Performance and Response to Geomagnetic Activity

Abstract:

A high-resolution empirical model for total electron content (TEC) based on GNSS TEC data provided by the CEDAR Madrigal database is further developed by extension to all longitudes at 45 degrees North with a 3 degree longitudinal resolution. Longitudinal variation in the response to geomagnetic activity is identified by analyzing the response of TEC values compared to background for four significant geomagnetic disturbances during 2015. These storms are chosen to represent each of the four seasons, occurring on 17 March 2015, 22 June 2015, 8 October 2015, and 21 December 2015. The timing and magnitude of positive and negative storm effects depend on the local time onset, rate of change of geomagnetic activity, and magnitude of the storm in question. The dependence of the performance of the model on longitude is also evaluated using common error metrics. The longitudinal dependence of the response in TEC and performance of the model are compared to past studies.