The Kennely Heaviside layer, also known as the ionosphere, is a region of the Earth's atmosphere that is ionized by solar radiation. Its spelling is unique due to the combination of the surnames of two scientists who discovered it independently. The correct pronunciation is kəˈnɛli ˈhevɪsaɪd ˌleɪər, with the stress on the first syllable of each name. The IPA phonetic transcription shows that the "k" is not silent, and the stress is on the first syllable of each name.
The Kennelly-Heaviside layer, also known as the E layer or the Heaviside layer, is a region within the Earth's ionosphere that is located at an altitude ranging from approximately 80 to 150 kilometers above the Earth's surface. It was named after two scientists, Arthur E. Kennelly and Oliver Heaviside, who independently discovered its existence in the early 20th century.
The Kennelly-Heaviside layer plays a crucial role in long-distance radio communication as it has the property of reflecting radio waves back to the Earth's surface, allowing for the transmission of radio signals over extended distances. This reflection occurs due to the presence of free electrons in the layer, which ionizes the surrounding atmosphere and causes it to become electrically conductive. As radio waves encounter the layer, they interact with the free electrons, leading to their reflection.
The thickness and density of the Kennelly-Heaviside layer can vary depending on various factors such as time of day, season, and solar activity. During the daytime, the layer typically becomes denser due to the increased ionization caused by solar radiation, while at nighttime, it thins out as the absence of the Sun reduces ionizing radiation.
This phenomenon is of particular interest and significance to the field of telecommunications as it enables long-range radio transmissions, including international broadcasts and long-distance radio communication. Understanding the properties and behavior of the Kennelly-Heaviside layer is essential for optimizing and improving the reliability of radio communication systems.