On 21 August 2017, a total solar eclipse traversed the continental United States and caused large‐scale changes in ionospheric densities. These were detected as changes in medium and high frequency radio propagation by the Solar Eclipse QSO Party (SEQP) citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse‐ionospheric study to make use of measurements from a citizen‐operated, global‐scale HF propagation network and develop tools for comparison to a physics‐based model ionosphere. Eclipse effects were observed ±0.3 hr on 1.8 MHz, ±0.75 hr on 3.5 and 7 MHz, and ±1 hr on 14 MHz and are consistent with eclipse‐induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h ≥ 125 km altitude with elevation angles θ ≥ 22°, while 14 MHz signals refracted at h < 125 km with elevation angles θ < 10°.
BT - Geophysical Research Letters DA - 05/2018 DO - https://doi.org/10.1029/2018GL077324 LA - eng M3 - Research Letter N2 -On 21 August 2017, a total solar eclipse traversed the continental United States and caused large‐scale changes in ionospheric densities. These were detected as changes in medium and high frequency radio propagation by the Solar Eclipse QSO Party (SEQP) citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse‐ionospheric study to make use of measurements from a citizen‐operated, global‐scale HF propagation network and develop tools for comparison to a physics‐based model ionosphere. Eclipse effects were observed ±0.3 hr on 1.8 MHz, ±0.75 hr on 3.5 and 7 MHz, and ±1 hr on 14 MHz and are consistent with eclipse‐induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h ≥ 125 km altitude with elevation angles θ ≥ 22°, while 14 MHz signals refracted at h < 125 km with elevation angles θ < 10°.
PY - 2018 T2 - Geophysical Research Letters TI - Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse UR - https://doi.org/10.1029/2018GL077324 VL - 45 SN - 1944-8007 ER -