@proceedings {925, title = {Software Development for the Grape Personal Space Weather Station v2}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The Grape 2 is a three-channel radio receiver and an integral component of the broader Personal Space Weather Station (PSWS) project. The PSWS network is a distributed array of radio receivers designed to continuously monitor changes in the Earth{\textquoteright}s ionosphere. It achieves this by tracking frequency standard stations, such as WWV, WWVH, and CHU, on a 24/7 basis. The system includes software tools for control and monitoring. Each Grape station transmits daily data to a centralized, publicly accessible database hosted by the University of Alabama, where automated processing generates spectrograms. These visualizations provide researchers with rapid insights into ionospheric conditions and enable long-term studies of space weather phenomena.\ 

}, author = {Cuong Nguyen and Nathaniel Frissell and John Gibbons and Bill Blackwell and Bill Engelke} } @proceedings {930, title = {The Solar Eclipse Inverse Problem}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

The HamSCI Personal Space Weather Station (PSWS) is a distributed network that includes magnetometers and high frequency receivers. The Great Radio Amateur Propagation Experiment (GRAPE) is a collection of PSWS receivers that record Doppler shift from national time standard signals. The Grape project includes Grape 1 receivers recording Doppler and spectral data as well as the upgraded Grape 2 three channel receivers and the multi-channel WSPR (Weak Signal Propagation Reporter) Grapes. The network collected data during the 2023 and 2024 solar eclipses on frequencies ranging from 2.5 to 20 MHz. The recorded Doppler shift indicates a change in signal path caused when the signal passes through the ionospheric layers in the Earth{\textquoteright}s atmosphere. Due to the scale and variability of the ionosphere, these measurements are sparse and are not accompanied by a known forward model. The reconstruction of eclipse period ionospheric behavior can therefore be viewed as a mathematical inverse problem. We explore various mathematical techniques and algorithms that could be used to solve the inverse problem and model the real time ionospheric behavior.

}, author = {Rachel Boedicker and Nathaniel Frissell and John Gibbons and Kristina Collins and David Kazdan} } @proceedings {970, title = {Southern Hemisphere MSTID response to a Sudden Stratospheric Warming Observed by the Falkland Islands SuperDARN Radar}, year = {2025}, month = {03/2025}, publisher = {HamSCI}, address = {Newark, NJ}, abstract = {

We present a study of Medium Scale Traveling Ionospheric Disturbances (MSTIDs) observed by the Falkland Islands Radar (FIR) in the Southern Hemisphere in response to a sudden stratospheric warming (SSW) event. MSTIDs are quasi-periodic variations in the upper atmospheric (~250 km altitude) plasma with phase speeds of ~100-250 m/s, periods from ~15-60 minutes, and horizontal wavelengths of several hundred kilometers. Daytime MSTIDs are known to be associated with gravity waves (GWs) that originate in the lower and middle atmosphere and propagate upward into the F-region. Neutral wind filtering of these GWs creates a strong dependence of GW-associated MSTIDs on stratospheric and mesospheric zonal wind direction and speed, which is tied to polar vortex strength during fall, winter, and spring months. This dependence manifests as both seasonal and sub-seasonal variability of MSTID amplitudes. Most existing SuperDARN MSTID studies have focused on observations from the Northern Hemisphere. This work uses an automated spectral approach previously used to study Northern Hemisphere winter daytime SuperDARN MSTIDs and applied it to all radars in both hemispheres for all times of day and all seasons for the years 2010-2021. This helped us identify the Southern Hemisphere radars with the highest quality data. One radar for which the retrievals worked particularly well was FIR which illustrates suppressed MSTID activity following the minor SSW beginning on 6 September 2019. This suggests that Southern Hemisphere MSTIDs, like their Northern Hemisphere counterparts, have GW sources in the lower/middle neutral atmosphere and are modulated by the polar vortex jet.\ 

}, author = {James Fox and Nicholas Guerra and Thomas Pisano and Michael Molzen and Nathaniel Frissell and Lynn Harvey and Joseph Klobusicky and Mark Fenner and Joseph Baker and Michael Ruohoniemi} }