The E region, also known as the E layer, is a part of the Earth's ionosphere, located approximately 90 to 150 kilometers above the Earth's surface. This region is characterized by the presence of ionized particles, which are created by solar radiation. The E layer plays a crucial role in radio wave propagation, as it can reflect certain frequencies back to the Earth's surface, allowing for long-distance communication. The E region is influenced by solar activity, such as solar flares and coronal mass ejections, which can enhance ionization levels. This variability can affect radio signals, making them stronger or weaker depending on the conditions in the E layer. Understanding the E region is important for fields like telecommunications and space weather forecasting.