(a) Time profile of dNe (blue) from Swarm C, dTEC_att (black dots) and corresponding spline fitting curve (red line) between 22:24:53 and 22:29:35 UT on January 15, 2022. (b) Map of dNe (blue line) from Swarm C on top of dTEC (with dTEC > 0:1 TECu) red and blue points in the same time interval of panel a. Deviations from dot-dashed line represent the reference (dNe = 0 cm⁻³) is proportional to the positive (right) and negative (left) dNe values.