W2NAF Gets NSF Grant to Study Grayline and Solar Eclipses

HamSCI founder and University of Scranton professor Nathaniel Frissell, W2NAF, has been awarded a nearly $400,000 grant from the National Science Foundation to study changes in the ionosphere at dawn and dusk (a period we hams know as “grayline”) and during solar eclipses. According to the university, Frissell will work with students there and at Case Western Reserve University, as well as amateurs around the country, to gather data using so-called “Grape” receivers designed using another NSF grant for the HamSCI Personal Space Weather Station project.

Grape receiver circuit board (from HamSCI.org
website)

Frissell says there will be an annular solar eclipse visible in the continental U.S. next year, as well as a total eclipse in 2024, noting that these will be the last solar eclipses to traverse the country until 2044. The grant will fund an additional 30 Grape receivers that will be provided to HamSCI volunteers across North America. The stations will run continuously at least through 2025, the end of the project period, monitoring WWV and CHU to collect data daily at sunrise and sunset as well as during the two solar eclipses.

In a post to the HamSCI e-mail group, Frissell says the project will have five main areas of study:

1. How do dawn and dusk ionospheric variability as observed by HF Doppler shift measurements vary with local time, season, latitude, longitude, frequency, distance, and direction from the transmitter?
2. Is eclipse ionospheric response symmetric with regard to onset and recovery timing?
3. How similar is the eclipse to daily dawn and dusk terminator passage?
4. Do we observe multipath HF mode-splitting in the post-eclipse interval that is similar to dawn events?
5. How is the response different for the southward annular eclipse in 2023 compared to the northward total eclipse of 2024?

According to Frissell, the grant will also provide support for a Ph.D. student at Case Western and a masters candidate at Scranton.