The SAMI2-derived TEC at altitudes above 400 km at ~1300 LT and at 25° LAT. The starred values are for a quiet time interval with a peak diurnal electric field of 0.53 mV m⁻¹ at 13 LT. The open triangles represent the TEC for the case of an electric field of 4 mV m⁻¹ for a 2 h duration. In the storm case, the TEC increases until a peak value of ~270 TEC units is reached. This closely matches the peak EIA observed by CHAMP.