The ionosphere is located between 46 and 621 miles above the Earth's surface and is composed of plasma, a state of matter that is a combination of free electrons and ionized atoms. The ionosphere contains the thermosphere and portions of the exosphere and the mesosphere.
The ionosphere is charged by radiation emanating from the sun. Ultraviolet solar radiation charges the particles, causing electrons to separate from atoms and electromagnetically mix with the remaining ions, creating the layer of plasma that surrounds the Earth.
This layer of plasma greatly influences atmospheric electricity, the electrical charges that are present in the Earth's atmosphere. The ionosphere is part of the global atmospheric electrical circuit. It plays an important role in propagating radio signals around the Earth. The radio signals bounce off of the ionosphere and ricochet to their intended recipient.
Geomagnetic solar storms, caused by solar flares and solar winds, can disrupt activity in the ionosphere. Disruptions in the ionosphere can cause difficulty with radio signal transmission and global positioning system signals.
The ionosphere is broken up into three different parts: the D-region, the E-region and the F-region. The existence of these regions is dependent on whether it's daytime or night time. The D-region ceases to exist at night, while the F-region is present during both day and night.