@proceedings {841, title = {On Final Approach To Solar Maximum: Testing A Hypothesis In Real Time (Keynote)}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, abstract = {

A bit more than ten years ago we made a discovery. We identified, and then archaeologically re-identified, a relationship between magnetic objects on the Sun at a range of spatial scales and the Sun{\textquoteright}s 22 year Magnetic (or Hale) Cycle. That pattern (unfortunately) is called the "extended solar cycle". Further, that investigation identified a specific event that occurs at the very end of Hale Cycles, the {\textquoteright}terminator,{\textquoteright} as being a critical component NECESSARY to explain how the Hale Cycle shapes the Sun{\textquoteright}s 11(-ish) year activity cycle. Fast forward a decade and we have successfully identified the terminator events going back beyond the earliest photography of the Sun (1860) to the mid-eighteenth century. Those 24 events permitted a forecast of Sunspot Cycle 25 to be made. That forecast became a {\textquoteright}litmus test{\textquoteright} for what we understand about the solar activity cycle and the mechanism that generates and sustains the Sun{\textquoteright}s large-scale magnetic field. Why? Because the forecast we arrived at was 100\% greater than that resulting from an assessment of the spectrum of models and forecasts in the community. We have been testing our hypothesis of the Sun{\textquoteright}s magnetism in real time since 2019. In this presentation we{\textquoteright}ll discuss the present status and talk about where things could go from here.

}, author = {Scott W. McIntosh} } @proceedings {821, title = {Five Years of prop.kc2g.com: Evolution of an HF Forecasting Tool}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, abstract = {

prop.kc2g.com first went online in January 2019. Let{\textquoteright}s take a look at the workings of the model, see how it{\textquoteright}s evolved over the years, and where it might go in the future. Source code for prop.kc2g.com is available at https://github.com/arodland/prop.

}, author = {Andrew Rodland} } @proceedings {837, title = {Forum: How Ham Radio Can Further Help Ionospheric Research}, year = {2024}, month = {03/2024}, publisher = {HamSCI}, address = {Cleveland, OH}, author = {Nathaniel A. Frissell} } @proceedings {754, title = {Father Joseph Murgas {\textquotedblleft}The Radio Priest{\textquotedblright}: Scientist, Inventor, Artist, and Naturalist}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, author = {Elaine Kollar} } @proceedings {744, title = {FDTD for Geophysical Applications}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

The finite-difference time-domain (FDTD) method [Yee, IEEE TAP, 14:3, 1966] is a robust method that solves Maxwell{\textquoteright}s equations in time and over a spatial grid.\  It can account for arbitrary source time-waveforms as could occur from man-made antennas as well as naturally occurring ionospheric currents or lightning strikes, etc.\  The FDTD method can also account for complex 3-D geometries, including for example a variable ground topography and 3-D lithosphere/ionosphere compositions.\  By coupling Maxwell{\textquoteright}s equations to the plasma momentum equation, FDTD models may also be constructed to account for the physics of electromagnetic wave propagation through magnetized ionospheric plasma.

Over the years, our research group has developed FDTD models of electromagnetic waves propagating globally around the world in the Earth-ionosphere waveguide [Simpson, Surveys in Geophysics, 30:2, 2009].\  Three generations of models have been developed:\  (1) a latitude-longitude grid; (2) a geodesic (hexagonal-pentagonal) grid; and (3) a Cartesian-based grid.\  These models have been applied to remote-sensing of localized ionospheric anomalies, remote-sensing of oil fields, geolocation, Schumann resonances, space weather effects on the operation of electric power grids, scintillation in the ionosphere, etc.\ \ 

In this presentation, we will provide an overview of our modeling capabilities, and we will also highlight a recent research activity relating to power line emissions (PLE) and power line harmonic radiation (PLHR) propagating into and through the ionosphere. For this project, the FDTD models are solve the full-vector Maxwell{\textquoteright}s equations coupled with the plasma momentum equation over a fully 3-D grid while considering the complex inhomogeneities of the ionospheric magnetized plasma (ducts, plasma bubbles, etc.). Our algorithm is highly efficient, allowing us to study the long timespans of the very low-frequency waveforms of interest as well as their long propagation paths from the ground to satellite altitudes.

Although we have not collaborated with Ham radio operators yet, we are very interested in doing so.\  Our models are ideally suited for investigating a number of interesting problems.\ 

}, author = {Apoorva Pedgaonkar and Jamesina Simpson} } @proceedings {693, title = {A Few Science Questions that HamSCI Can Help Address During the 2023 and 2024 Eclipses}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Solar eclipses are an exciting celestial event which can be used to study the terrestrial atmosphere and ionosphere systems. Locally, during a total solar eclipse, totality may only last a few minutes{\textemdash}and the times scales on which solar illumination decreases and then increases is much shorter that what is normally observed during sunrise and sunset. Additionally, on a larger, continental scale, the moon{\textquoteright}s umbra moves at supersonic velocities, tracing out the path of totality. These properties serve to act as an impulse in energy on the atmosphere and ionosphere, generating a wide variety of yet to be specified (or identified) responses in those systems.\ 

As an example of some compelling response effects, the fast depletion-replenishment of the bottomside ionosphere (the portion of the ionosphere that is below the F-region peak) often appears asymmetric{\textemdash}an observation that is not well understood. Therefore, one science question which can be addressed is: will the different geometries of the 2023 and 2024 eclipses as well as the fact that they are an annular and total eclipse, respectively, have a significant effect on the asymmetry of the bottomside evolution during the eclipse? Furthermore, efforts to model and replicate the observed effects of eclipses have significantly improved in recent years; however, observations of the atmosphere and ionosphere are still required to constrain, validate, and ultimately improve our theoretical understanding of these systems. Another eclipse science question which can be addressed is: how well will these models perform for the 2023 and 2024 eclipse and how can we quantify the response of the ionosphere during these events?\ 

Over the past few years, HamSCI has emerged at the forefront of passive remote sensing techniques in solar-terrestrial physics. This is evidenced by HamSCI{\textquoteright}s work using with HF timing signals and HF QSOs, show that both can be used to monitor the bottomside ionosphere on both regional and continental scales. The SEQP during the 2017 total solar eclipse was a resounding success, delivering high-impact and influential science results. Building upon that success, this technique may very well be a gamechanger for identifying and characterizing eclipse generated effects and phenomena during the upcoming 2023 and 2024 eclipses. The purpose of this presentation is to detail a few outstanding eclipse related science questions, and propose how HamSCI can lead the way in addressing them.

}, author = {Gareth W. Perry and Nathaniel A. Frissell and Joseph D. Huba} } @proceedings {724, title = {Field-Aligned Potential Drops in an Ionospheric Streamer}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Field-aligned potential drops occur primarily in regions of strong upward field-aligned currents, where they can decouple the ionospheric and magnetospheric dynamics. They have been a challenge to incorporate into global magnetosphere modeling efforts. Low-entropy bubbles can form ionospheric streamers in the context of field-aligned potential drops. We have made a simple zeroth-order analytic model with order-of-magnitude reasonable field values. The model{\textquoteright}s parameter space comprises resistivity, bubble asymmetry, conductivity enhancement, and an additional parameter which can be used to adjust the entropy profiles across the bubble. We are currently exploring this parameter space and examining the resulting differences between the resulting ionospheric and magnetospheric electric fields (including electric field-reversals).\  An examination of whether bursty bulk flows or flow bursts are more likely to be responsible for streamers is ongoing.\  Both previous runs of the Rice Convection Model and data are being used to fit parameters and examine reasonable parameter regimes.

}, author = {Jason Derr and Sina Sadegzadeh and Richard Wolf and Frank Toffoletto and Jian Yang and Weiqin Sun} } @article {798, title = {Forging Amateur-Professional Bonds: An Overview of the HamSCI 2023 Workshop and the Upcoming Solar Eclipses}, volume = {79}, year = {2023}, month = {07/2023}, pages = {32-26}, type = {General Interest}, abstract = {

HamSCI {\textendash} the Ham Radio Science Citizen Investigation, a collaboration between the amateur radio and space science communities - held its sixth annual workshop this spring at The University of Scranton in Scranton, Pennsylvania.

}, issn = {0007-893X}, url = {https://cq-amateur-radio.com}, author = {Wilcox, R} } @proceedings {704, title = {Forging Amateur-Professional Bonds (Keynote Address)}, year = {2023}, month = {03/2023}, publisher = {HamSCI}, address = {Scranton, PA}, abstract = {

Amateurs have played an important role in scientific research for many centuries. Up until the time of automated computerized telescope searches, virtually all comets were discovered by amateurs. As David Levy (of comet Shoemaker-Levy fame) said, "Amateurs have time to observe and enjoy the sky. Professionals have to submit proposals, take data, and write papers." Amateurs have long held associations with professional scientists in the realms of botany, ornithology, and even fossil and meteorite hunting. Ham Radio operators have worked closely with meteorologists as stormspotters and to provide communication in times of severe weather or other emergencies. It is a very natural outgrowth that Ham Radio amateurs team up with space physicists and aeronomers who study the ionosphere and its dependences on solar disturbances, in the general term of "space weather". Stanford first created VHF SID ionospheric monitors for amateurs and schools, and the "Radio Jove" program from Goddard has enlisted amateurs in monitoring solar and Jovian radio emissions. Ham beacons using Joe Taylor{\textquoteright}s compression algorithms now are used to track amateur balloons that have sailed four more times around the Earth. Amateurs team up with college students to provide communication with Cubesats. We are entering a new era of amateur radio providing important information on the structure and variability of the ionosphere, especially during eclipses. Several HamSCI talks and posters were shown at the recent Chicago AGU meeting, and we look to this group to lead the way for future uses of ham radio in "real" scientific research. talks and posters were shown at the recent Chicago AGU meeting, and we look to this group to lead the way for future uses of ham radio in "real" scientific research.

}, author = {Reiff, Patricia} } @proceedings {608, title = {Forecasting Spread F at Jicamarca}, year = {2022}, month = {03/2022}, publisher = {HamSCI}, address = {Huntsville, AL}, abstract = {

Spread F is a phenomenon that occurs in the F layer of the Ionosphere and is characterized by plasma depletions. It can have a negative impact on radio communication systems and because of this, it is of interest to develop a model that can predict its occurrence. Radars like digisondes and JULIA (Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere) have observed the Ionosphere at Jicamarca for decades. The datasets that resulted from a collection of these observations joined with geophysical parameters measurements were harnessed to train a Machine Learning model that predicts Spread F. In addition, we compared our model to FIRST (Forecasting Ionospheric Real-time Scintillation Tool) and obtained promising results. Although our model has only been validated with Jicamarca{\textquoteright}s dataset it may be used for other longitudes. Furthermore, since the only local measurements used during training were Spread F occurrences and the virtual height of the F layer, the retraining process can easily be done on a single station with an ionosonde receiver.

}, author = {Reynaldo O. Rojas and Enrique L. Rojas and Jhassmin A. Aricoch{\'e} and Marco A. Milla} } @article {670, title = {Fostering Collaborations with the Amateur Radio Community}, journal = {White Paper Submitted to the National Academy of Sciences Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033}, year = {2022}, doi = {10.3847/25c2cfeb.09fe22b4}, author = {Nathaniel A. Frissell and Laura Brandt and Stephen A. Cerwin and Kristina V. Collins and Timothy J. Duffy and David Kazdan and John Gibbons and William D. Engelke and Rachel M. Frissell and Robert B. Gerzoff and Stephen R. Kaeppler and Vincent Ledvina and William Liles and Elizabeth MacDonald and Gareth W. Perry and Jonathan D. Rizzo and Diego F. Sanchez and H. Lawrence Serra and H. Ward Silver and Tamitha Mulligan Skov and Mary Lou West} } @proceedings {434, title = {Frequency Estimation Techniques}, year = {2020}, month = {09/2020}, publisher = {ARRL-TAPR}, address = {Virtual}, url = {https://www.youtube.com/watch?v=n9p0FpZkxE4}, author = {Kazdan, David} } @conference {312, title = {FPGA-based HF transceiver running on an RPi with a MW loop antenna that works well indoors (Demonstration)}, booktitle = {HamSCI Workshop 2019}, year = {2019}, month = {03/2019}, publisher = {HamSCI}, organization = {HamSCI}, address = {Cleveland, OH}, author = {Cowling, Scotty} } @article {231, title = {Faraday Rotation of Automatic Dependent Surveillance-Broadcast (ADS-B) Signals as a Method of Ionospheric Characterization}, journal = {Radio Sci.}, volume = {52}, year = {2017}, month = {2017}, pages = {1293 - 1300}, abstract = {

Radio waves propagating through plasma in the Earth{\textquoteright}s ambient magnetic field experience Faraday rotation; the plane of the electric field of a linearly polarized wave changes as a function of the distance travelled through a plasma. Linearly polarized radio waves at 1090 MHz frequency are emitted by Automatic Dependent Surveillance Broadcast (ADS-B) devices that are installed on most commercial aircraft. These radio waves can be detected by satellites in low Earth orbits, and the change of the polarization angle caused by propagation through the terrestrial ionosphere can be measured. In this manuscript we discuss how these measurements can be used to characterize the ionospheric conditions. In the present study, we compute the amount of Faraday rotation from a prescribed total electron content value and two of the profile parameters of the NeQuick ionospheric model.

}, keywords = {2443 Midlatitude ionosphere, 2447 Modeling and forecasting, 2467 Plasma temperature and density, 2494 Instruments and techniques, Automatic Dependent Surveillance-Broadcst (ADS-B), electron density, Faraday rotation, ionosphere, total electron content (TEC)}, isbn = {1944-799X}, doi = {10.1002/2017RS006319}, url = {http://dx.doi.org/10.1002/2017RS006319}, author = {Cushley, A. C. and Kabin, K. and No{\"e}l, J.-M.} } @conference {176, title = {Fitting Ionospheric Models Using Real-Time HF Amateur Radio Observations}, booktitle = {NSF CEDAR (Coupling, Energetics, and Dynamics of Atmospheric Regions)}, year = {2017}, month = {06/2017}, address = {Keystone, CO}, author = {J. D. Katz and N. A. Frissell and J. S. Vega and A. J. Gerrard and R. B. Gerzoff and P. J. Erickson and E. S. Miller and M. L. Moses and F. Ceglia and D. Pascoe and N. Sinanis and P. Smith and R. Williams and A. Shovkoplyas} }