(A–D) Comparison of the TEC, f _o F₂, f _o E and slab thickness behaviour during the eclipses of 3 October 2005 (left side) and 20 March 2015 (right side). The instantaneous measurements are denoted with black dots, the (approximated) daytime trend is plotted with a dashed grey curve and the (approximated) median behaviour with a solid grey curve. The shading covers the time period of the eclipse over Brussels and the measurements during the eclipse are highlighted with a solid black curve.