@conference {383, title = {Observations and Modeling Studies of the Effects of the 2017 Solar Eclipse on SuperDARN HF Propagation}, booktitle = {HamSCI Workshop 2020}, year = {2020}, month = {03/2020}, publisher = {HamSCI}, organization = {HamSCI}, address = {Scranton, PA}, abstract = {

The total solar eclipses offer a unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. Unique responses may be witnessed during eclipses, including changes in radio frequency (RF) propagation at high frequency (HF). Such changes in RF propagation were observed by the Super Dual Auroral Radar Network (SuperDARN) radars in Christmas Valley, Oregon and in Fort Hayes, Kansas during the 2017 solar eclipse. At each site, the westward looking radar observed an increase in slant range of the backscattered signal during the eclipse onset followed by a decrease after totality. In order to investigate the underlying processes governing the ionospheric response to the eclipse, we employed the HF propagation toolbox (PHaRLAP), created by Dr. Manuel Cervera, to simulate SuperDARN data for different models of the eclipsed ionosphere. By invoking different hypotheses and comparing simulated results to SuperDARN measurements we could study the underlying processes governing the ionosphere and improve our model of the F-Region responses to an eclipse. This method was used in three studies to: identify the cause of the increase in the distance radio waves traveled during the eclipse; evaluate different models of change in eclipse magnitude over time; and investigate the effect of the neutral wind velocity on the simulated eclipse data. This presentation will discuss observations made by SuperDARN during the 2017 eclipse, major results from our raytrace studies, and unanswered questions that may be useful to consider when planning HamSCI{\textquoteright}s campaign and/or similar ionospheric studies for the next eclipse over the United States in 2024.

}, author = {M. Moses and L. Kordella and G. D. Earle and D. Drob and J. Huba and J. M. Ruohoniemi} } @conference {236, title = {Initial Results of HamSCI Ham Radio 21 August 2017 Eclipse Ionospheric Experiments}, booktitle = {American Meteorological Society Annual Meeting}, year = {2018}, month = {01/2018}, publisher = {American Meteorological Society}, organization = {American Meteorological Society}, address = {Austin, TX}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. Despite more than 60 years of research, questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. We present initial results from three amateur radio experiments designed to study the 2017 total solar eclipse: the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT). These experiments are coordinated by HamSCI, the Ham Radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://ams.confex.com/ams/98Annual/webprogram/Paper337094.html}, author = {N. A. Frissell and J. R. Ackermann and D. Bern and F. Ceglia and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. Gerzoff and P. Gladstone and S. W. Gunning and J. D. Huba and J. D. Katz and E. S. Miller and M. L. Moses and S. E. Reyer and S. W. Rose and A. Shovkoplyas and H. W. Silver and P. Smith and J. S. Vega and M. L. West and R. Williams} } @article {248, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, journal = {Geophysical Research Letters}, volume = {45}, year = {2018}, month = {05/2018}, type = {Research Letter}, abstract = {

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 {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}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{\textdegree}, while 14 MHz signals refracted at\ h \< 125 km with elevation angles\ θ \< 10{\textdegree}.

}, issn = {1944-8007}, doi = {https://doi.org/10.1029/2018GL077324}, url = {https://doi.org/10.1029/2018GL077324}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and G. D. Earle and M. L. Moses and M. L. West and J. D. Huba and P. J. Erickson and E. S. Miller and R. B. Gerzoff and W. Liles and H. W. Silver} } @conference {172, title = {Analysis of the August 2017 Eclipse{\textquoteright}s Effect on Radio Wave Propagation Employing a Raytrace Algorithm}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, abstract = {

The upcoming total solar eclipse over the continental United States on August 21 offers an unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. There are significant differences between the conditions during a solar eclipse and the conditions normally experienced at sunset and sunrise, including the west-to-east motion of the eclipse terminator, the duration of the event, the solar zenith angle, and the continued visibility of the corona. Taken together, these factors imply that unique ionospheric responses may be witnessed during eclipses, as measured by changes in radio frequency (RF) propagation. High Frequency (HF) propagation varies greatly depending on ionospheric conditions. Hence, our analysis will include data collected during the eclipse by several HF systems shown in Figure 1 including SuperDARN, temporary radio transceiver sites, and amateur radio networks such as the Reverse Beacon Network (RBN) and Weak Signal Propagation Reporter Network (WSPRNet). The data analysis will be guided by raytrace models of HF propagation through an eclipsed ionosphere employing the HF propagation toolbox, PHaRLAP (created by Dr. Manuel Cervera).

}, author = {M. L. Moses and S. Burujupali and K. Brosie and S. Dixit and G. D. Earle and L. Kordella and N. A. Frissell and C. Chitale} } @conference {175, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppller and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {226, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {2017 Annual Meeting of the APS Mid-Atlantic Section}, year = {2017}, month = {11/2017}, publisher = {American Physical Society}, organization = {American Physical Society}, address = {Newark, NJ}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and M. L. West and G. D. Earle and M. L. Moses and H. W. Silver} } @conference {230, title = {HamSCI and the 2017 Total Solar Eclipse}, booktitle = {American Geophysical Union Fall Meeting}, year = {2017}, month = {12/2017}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {New Orleans, LA}, author = {N. A. Frissell and J. D. Katz and S. W. Gunning and J. S. Vega and A. J. Gerrard and M. L. Moses and G. D. Earle and M. L. West and P. J. Erickson and E. S. Miller and R. Gerzoff and H. Ward Silver} } @conference {207, title = {HamSCI and the 2017 Total Solar Eclipse (Experiment Description)}, booktitle = {ARRL and TAPR Digital Communications Conference}, year = {2017}, month = {09/2017}, address = {St. Louis, MO}, abstract = {

On 21 August 2017, a total solar eclipse will cause the shadow of the moon to traverse the United States from Oregon to South Carolina in just over 90 minutes. The sudden absence of sunlight due to the eclipse, especially solar UV and x-rays, provides an impulse function to the upper atmosphere that modifies the neutral dynamics, plasma concentrations, and related properties. In spite of more than 60 years of research, open questions remain regarding eclipse-induced ionospheric impacts. Ham radio operators{\textquoteright} advanced technical skills and inherent interest in ionospheric science make the amateur radio community ideal for contributing to and and participating in large-scale ionospheric sounding experiments. This pa- per describes the Solar Eclipse QSO Party (SEQP), the HF Wideband Recording Experiment, and the Eclipse Frequency Measurement Test (FMT), three amateur radio experiments designed to study the 2017 total solar eclipse. These experi- ments are coordinated by HamSCI, the Ham radio Science Citizen Investigation, a citizen science organization that connects the amateur radio community to the professional space science research community for mutual benefit.

}, url = {https://www.tapr.org/pub_dcc.html}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and S. W. Gunning and A. J. Gerrard and M. L. Moses and G. D. Earle and E. S. Miller and J. D. Huba and M. Hirsch and H. W. Silver and S. E. Reyer and J. R. Ackermann and M. D. Suhar and D. Bern} } @conference {174, title = {HamSCI: The Ham Radio Science Citizen Investigation (Banquet Presentation)}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. R. Ackermann and J. Dzekevich and G. D. Earle and P. J. Erickson and A. J. Gerrard and R. B. Gerzoff and S. W. Gunning and M. Hirsch and J. D. Katz and S. R. Kaeppler and R. W. McGwier and E. S. Miller and M. L. Moses and G. Perry and S. E. Reyer and A. Shovkoplyas and H. W. Silver and J. S. Vega and RBN Team} } @conference {173, title = {Ionospheric Simulations of the 2017 Solar Eclipse QSO Party}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {N. A. Frissell and J. S. Vega and J. D. Katz and M. L. Moses and G. D. Earle and S. W. Gunning and A. J. Gerrard and E. S. Miller and M. L. West and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas and H. W. Silver} }