NASA printed this original article by McKenzie Denton (KO4GLN) – a member of the Williamsburg Space Newbie Radio Membership and the Lengthy Island CW membership – on September 25, 2023. Edits by EarthSky.
Do solar eclipses have an effect on Earth’s ambiance?
Solar eclipses can have a noticeable influence on the construction and dynamics of Earth’s higher ambiance, the ionosphere. That is primarily as a result of sudden drop in solar radiation reaching the Earth’s ambiance in the course of the eclipse. For the reason that ionosphere incorporates charged particles (ions and electrons) and is answerable for reflecting and refracting radio waves, adjustments to the ionosphere may also have an effect on radio communications and navigation methods.
Read: Annular solar eclipse of October 14, 2023
Impacts on the ionosphere
Right here’s how solar eclipses have an effect on the construction and dynamics of Earth’s ionosphere:
Ionization adjustments: Within the ionosphere, solar radiation is a major supply of ionization. Ionization is when an atom or molecule turns into charged whereas gaining or dropping electrons. Throughout a solar eclipse, much less solar radiation results in much less ionization, particularly 37 to 56 miles (60-90 km) up within the ambiance. This lower in ionization may cause a short lived drop within the density of electrons within the ionosphere.
Temperature adjustments: The drop in solar radiation throughout an eclipse may also result in cooling of the higher ambiance. This cooling can doubtlessly trigger adjustments in ionospheric densities and altitudes.
Electron density variations: The discount in ionization and cooling throughout an eclipse can result in a lower within the electron density within the ionosphere. This will have an effect on the propagation of radio waves, significantly within the excessive frequency, or HF, vary. Radio waves use ionospheric reflection for long-distance communication.
Ionospheric anomalies: The sudden adjustments in ionospheric circumstances throughout an eclipse can result in the formation of ionospheric anomalies, similar to holes or depletions. These anomalies can disrupt radio alerts and GPS navigation methods, affecting communication and navigation over the affected areas.
Propagation results: The altered ionospheric circumstances throughout an eclipse can change how radio waves propagate via the ionosphere. This will trigger sign fading, absorption and refraction, affecting shortwave and satellite communication methods.
What does this imply in layman’s phrases?
Principally, the ionosphere – excessive up in Earth’s ambiance – will get much less daylight and due to this fact cools throughout a total solar eclipse. This cooling can deplete a few of the particles there, inflicting holes. Lengthy-distance radio waves might not be capable of bounce off the ionosphere in these areas to return their alerts to Earth. As well as, different waves that go via the ionosphere, like these utilized by GPS and communication satellites, are affected by the density change, which could trigger disruptions.
However all these results are solely short-term and within the area the place the eclipse is passing.
Photo voltaic eclipses are a chance for analysis
Photo voltaic eclipses present a novel alternative for researchers to review the ionosphere and its response to sudden adjustments in solar radiation. Scientists can use varied devices, similar to ionosondes, GPS receivers and radar methods, to measure and monitor ionospheric variations throughout an eclipse. These research will assist enhance our understanding of the ionosphere.
Whereas solar eclipses can have noticeable results on the ionosphere, they’re usually short-term and localized to the area experiencing the eclipse. The ionosphere usually returns to its regular state after the eclipse occasion is over, and solar radiation ranges return to regular.
Should you’re focused on studying extra about this matter, go to our web site at https://hamsci.org/. HamSCI – the Ham Radio Science Citizen Investigation – furthers radio science with the assistance of beginner radio operators. HamSCI will host the Festivals of Eclipse Ionospheric Science in 2023 and 2024 to collect information for space physics analysis and assist scientists perceive how eclipses influence the ionosphere’s construction and dynamics.
Participation is open to volunteer beginner radio operators, brief wave listeners, and scientific researchers.
Backside line: Hear from a ham radio operator about how solar eclipses briefly have an effect on Earth’s higher ambiance, or ionosphere. Eclipses can disrupt radio alerts and GPS within the area the place the eclipse is passing.
Read more: Total solar eclipse in North America April 8, 2024
