Fig. 4
From: Comparison of terrestrial and Martian TEC at dawn and dusk during solstices
Annual variations in Martian (red) and Terrestrial (blue) TEC (top panels), solar irradiance (middle panels) and heliocentric distance (bottom panel) as functions of solar longitude. The planetary aphelion and perhelion are marked by dashed and dotted lines, respectively. The period of time included in each solstice season is marked by grey boxes