Eclipses create a natural experiment for observing how the ionosphere responds to rapid changes in solar radiation. By listening to shortwave radio stations during an eclipse, researchers and radio enthusiasts can study how ionospheric properties affect radio signal strength, propagation, and fading. This helps improve understanding of radio communications critical for emergency responders, aviation, maritime navigation, and global communication. Specifically, the eclipse-induced "night-like" conditions temporarily reduce the ionospheric absorption of radio waves, enhancing the reception of distant shortwave broadcasts that are otherwise masked during daylight [1][2][3][4].
In summary, listening to shortwave radio during a moon or solar eclipse provides an opportunity to observe and study atmospheric and ionospheric changes that impact radio wave behavior and communication capabilities.
Citations:
[1] Audio eclipse may fill the sky - EurekAlert! https://www.eurekalert.org/news-releases/1021230
[2] “Observe” August's Eclipse with Your AM Radio - Sky & Telescope https://skyandtelescope.org/2017-total-solar-eclipse/how-to-hear-the-solar-eclipse/
[3] How Ham Radio Operators Do Eclipse Science https://www.sciencefriday.com/articles/ham-radio-eclipse-citizen-science/
[4] The Solar Eclipse and Ham Radio https://www.nutsvolts.com/magazine/article/the-solar-eclipse-and-ham-radio
[5] The odd way eclipses affect radio - BBC https://www.bbc.com/future/article/20231005-eclipses-do-odd-things-to-radio-waves-to-learn-more-an-army-of-american-amateurs-will-broadcast-during-the-next-ones
[6] Beyond DXing: Analyzing Medium Wave Propagation During the ... https://swling.com/blog/2025/02/beyond-dxing-analyzing-medium-wave-propagation-during-the-2023-annular-eclipse/
[7] Ride the Wave of Radio Astronomy During the Solar Eclipse https://science.nasa.gov/solar-system/skywatching/ride-the-wave-of-radio-astronomy-during-the-solar-eclipse/
[8] How is it like to use radio during an eclipse? : r/HamRadio - Reddit https://www.reddit.com/r/HamRadio/comments/1k15jvc/how_is_it_like_to_use_radio_during_an_eclipse/
[9] Ham Radios Crowdsourced Ionospheric Science During Eclipse - Eos https://eos.org/articles/ham-radios-crowdsourced-ionospheric-science-during-eclipse
[10] Eclipse Radio: Several NASA-Funded Science Projects https://swling.com/blog/2024/02/eclipse-radio-several-nasa-funded-science-projects/
[11] Ham Radio Operators, We Need Your Help During Solar Eclipses! https://science.nasa.gov/get-involved/citizen-science/ham-radio-operators-we-need-your-help-during-solar-eclipses/
[12] NASA-Funded Science Projects Tuning In to 'Eclipse Radio' https://science.nasa.gov/solar-system/skywatching/nasa-funded-science-projects-tuning-in-to-eclipse-radio/
[13] Sky and Telescope: “Observe” August's Eclipse with Your AM Radio https://swling.com/blog/2017/06/sky-and-telescope-observe-augusts-eclipse-with-your-am-radio/
[14] HamSCI Reminder: Contribute to ionospheric research during the ... https://swling.com/blog/2023/10/hamsci-reminder-contribute-to-ionospheric-research-during-the-october-14-2023-solar-eclipse/
[15] Eclipses do odd things to radio waves. An army of amateur ... https://www.reddit.com/r/amateurradio/comments/1716y1c/eclipses_do_odd_things_to_radio_waves_an_army_of/
[16] Monitoring radio reception during the eclipse https://www.ukssdc.ac.uk/ionosondes/eclipse/outline.html
[17] Effect of total lunar eclipse of 27th July 2018 on the D- ... https://www.sciencedirect.com/science/article/abs/pii/S0273117721007201
[18] Shortwave radio proves simple, powerful — and necessary - RedTech https://www.redtech.pro/shortwave-radio-proves-simple-powerful-and-necessary/
[19] Ham Radio Operators' Ionospheric Science During The ... https://hackaday.com/2023/10/31/ham-radio-operators-ionospheric-science-during-the-solar-eclipse/
