Ionosfääris

Ionosfääris is a layer of Earth’s upper atmosphere, consisting primarily of ionised gases. It extends from about 60 km to 1000 km above the planet’s surface and is typically divided into several sub‑layers: D, E, F1 and F2. Ionisation in the ionosfääris is mainly caused by solar ultraviolet and X‑ray radiation, which strip electrons from neutral atoms and molecules, creating free electrons and positively charged ions. Because of this high concentration of charged particles, the ionosfääris can reflect, refract or absorb radio waves, making it crucial for long‑distance radio communications and navigation systems. The density and composition of the ionosfääris vary with time of day, season, solar activity and geographic location. During daytime the layers are more pronounced, whereas at night the D layer largely disappears, resulting in a reduction of radio wave absorption. Solar flares and geomagnetic storms can enhance ionisation, leading to disruptions in radio transmission and GPS accuracy. The ionosfääris is also a key region for space weather studies, as its interactions with Earth’s magnetic field and solar wind influence satellite drag, auroral formations and the behavior of high‑altitude instruments. Scientists monitor the ionosfääris using ground‑based ionosondes, satellite missions and radio occultation techniques to better understand its dynamics and mitigate its effects on communication and navigation infrastructure.