Ionosfääriä

The ionosphere is a region of Earth's upper atmosphere, approximately 60 to 1,000 kilometers above the surface, where atmospheric gases are ionized by solar radiation. This ionization creates a layer of charged particles, including free electrons and ions. The density of ionization varies significantly with altitude, time of day, season, and solar activity. During the day, the ionosphere is much more ionized due to direct exposure to ultraviolet and X-ray radiation from the sun. At night, recombination of electrons and ions reduces the ionization levels.

The ionosphere plays a crucial role in radio wave propagation. Its charged layers can reflect and refract radio waves, allowing for long-distance communication beyond the line of sight. Different layers within the ionosphere, such as the D, E, and F layers, have distinct ionization densities and affect radio wave propagation differently across various frequencies. The D layer absorbs most radio waves, while the E and F layers are responsible for reflection.

The ionosphere is also responsible for phenomena like auroras, which occur when charged particles from the sun interact with the Earth's magnetic field and atmosphere in this region. Understanding the ionosphere is vital for technologies such as satellite communication, GPS, and radar systems, as its conditions can impact their performance.