All panels show slices of electron density profiles from the ground up to 20.000 km. They are referred to the maps at 0 hours UT of DOY 073.

Left parts of the graphs are correspondent to the daytime. Right sides of the graphs are related to the nighttime.

y-axis is related to the Earth's rotation axis, named Z axis in the cartesian coordinate frame.

x-axis is related to the geographical X axis in the cartesian coordinate frame.

Top-left panel is related to the longitude meridians cutting the Earth in -180° and 0°.

Top-right panel is related to the longitude meridians cutting the Earth in -160° and 20°.

Bottom-left panel is related to the longitude meridians cutting the Earth in -140° and 40°.

Bottom-right panel is related to the longitude meridians cutting the Earth in -120° and 60°.

The color is giving in log scale.