Amateur Radio will be in the service of science on Monday, August 21, as a total solar eclipse causes the shadow of the moon to traverse the US from Oregon to South Carolina in a little more than 90 minutes, obscuring the sun completely for a few minutes at any given location along the way. The sudden absence of sunlight — and especially of solar ultra-violet and x-rays — is expected to change briefly the properties of the upper atmosphere. A few hundred radio amateurs already have registered as participants in the Solar Eclipse QSO Party (SEQP), a special operating event organized by the Ham Radio Science Citizen Investigation (HamSCI), which will contribute to the study of the eclipse’s impact on the ionosphere. HamSCI’s Nathaniel Frissell, W2NAF, said those taking part in the SEQP do not have to be in the path of totality to contribute to the research.
“It is very important for people outside of eclipse totality to participate, because one of the questions we have is how large is the effect on the ionosphere,” Frissell told ARRL. “So, we actually need people well outside of where totality is occurring to identify those boundaries.”
Frissell, an assistant research professor at the New Jersey Institute of Technology (NJIT), said it’s easy to be a citizen-scientist. Just getting on the air during the SEQP is a first step. Systems such as the Reverse Beacon Network (RBN), WSPRNet, and PSKReporter will automatically hear digital and CW transmissions and report back to their respective databases.
Despite more than 60 years of research, “open questions remain regarding eclipse-induced ionospheric impacts,” Frissell explained in a paper, “HamSCI and the 2017 Total Solar Eclipse,” that he’ll deliver at the ARRL-TAPR Digital Communications Conference this year. He feels that radio amateurs’ advanced technical skills and inherent interest in ionospheric science make them “ideal for contributing to — and participating — in large-scale ionospheric sounding experiments.”
Actually, three HamSci-coordinated Amateur Radio experiments have been designed to study the 2017 solar eclipse. In addition to the SEQP are the HF Wideband Recording Experiment and the Eclipse Frequency Measurement Test (FMT). According to research cited in the paper authored by Frissell and others, rapid changes in ionospheric electron density caused by the motion of an eclipse shadow “cause Doppler shifts on HF ray paths propagating through the eclipsed region.”
The HamSCI Wideband Recording Experiment Recording Experiment will aim to capture all Amateur Radio HF spectrum from locations across North America during the SEQP. The recordings, according to Frissell’s paper, “will allow for the study of eclipse-induced propagation changes use signals generated by the SEQP, as well as examine changes in noise floor measurements throughout the time of the eclipse.” The experiment was developed with input from the TAPR community.
The FMT experiment will provide information as to how much and how fast the ionosphere changes in height along a particular path. According to research cited in the paper authored by Frissell et al., rapid changes in ionospheric electron density caused by the motion of an eclipse shadow “cause Doppler shifts on HF ray paths propagating through the eclipsed region.”
“Joe Huba and Doug Drob at the Naval Research Laboratory have calculated a prediction of what the ionosphere will look like using their physics-based SAMI3 model.” Frissell pointed out.
ARRL Contributing Editor Ward Silver, N0AX — a contributor to “HamSCI and the 2017 Total Solar Eclipse” — said the SEQP is simply a great way to experience the magic of radio.
“If you’re a long-time HFer, you will hear the day-night cycle compressed and accelerated into a few hours, plus maybe some subtle things you’ve never heard before,” Silver said. “If you are new to HF, you can clearly experience the bands changing, opening, closing very quickly. You can literally hear the world turning during this eclipse. All you have to do is turn on the radio and make contacts. Listening or operating, it will be a thrill that you can only get through ham radio.”
It is not necessary to register for the SEQP in order to participate, Silver pointed out, and many more stations than those who have signed up are likely to be on the air on August 21. Multiple Amateur Radio special events also will be on the air along the path of totality on August 21.