Plain Language Summary: Radio communications using the high‐frequency (HF) bands (3–30 MHz) is important for emergency communications because it is the only form of electronic communications that can travel over the horizon without relying on man‐made infrastructure such as the Internet, satellite systems, or phone networks. This is possible because HF rays can be bent back to Earth by the ionosphere, an electrically charged layer of the upper atmosphere. Space weather events such as X‐ray flares from the Sun and geomagnetic storms can alter the ionosphere to disrupt these communications. During September 2017, a significant number of solar flares and geomagnetic activity occurred. Simultaneously, major hurricanes, including Hurricane Irma and Hurricane Jose, caused situations in the Caribbean region requiring the use of emergency HF communications, often provided by ham (amateur) radio operators. This paper shows the impacts of these space weather disturbances on HF communications as observed by multiple ham radio monitoring systems.
SEQP logs and data submitted to hamsci.org are now available for download from the Zenodo Data Repository HamSCI Community. This archive contains the locations, logs, and station descriptions submitted by operators to hamsci.org following the SEQP, as well as an aggregated, geolocated archive in CSV format of all Reverse Beacon Network (RBN), WSPRNet, PSKReporter, DXCluster, and SEQP log QSOs. The final rules of the SEQP have also been archived here. More information about the SEQP can be found at http://hamsci.org/seqp, and a published analysis of RBN observations over the United States by Frissell et al. (2018) may be found at https://doi.org/10.1029/2018GL077324.
This week, many HamSCI members are presenting their research at the American Geophysical Union (AGU) Fall Meeting in Washington, D.C. The AGU Fall meeting is one of the largest geoscience meetings in the world, and consists of about 24,000 attendees. The scientific program includes sessions pertaining to all areas of geophysics, including space weather, the solar wind, auroral activity, the ionosphere, and the neutral atmosphere. Below is a list of selected presentations and sessions being given by HamSCI members, or of general interest to ham radio operators. The complete scientific program is available here.
In his recent QEX article, “Ionospheric Disturbances at Dawn, Dusk, and During the 2017 Eclipse,” Steve Cerwin, WA5FRF published his analysis of observations of WWV (5 MHz) and WWVB (60 kHz) transmitters in Ft. Collins, CO as received at his home in San Antonio, TX. Cerwin reports that during the August 21, 2017 eclipse, a definite and measurable enhancement of low frequency (LF) and high frequency (HF) signals from his station. In addition to eclipse observations, Cerwin also examined the dawn and dusk transitions on both frequencies. Notable findings include a propagation null on WWVB that is correlated in time with dusk and dawn, and is consistent with destructive interference from a combination of ionospheric skip and ground-wave multipath propagation. Cerwin also reports on increased frequency jitter at 5 MHz during these times, as well a radical positive frequency swing at dawn and a negative swing at dusk.
The results of the 2015 CASSIOPE ePOP - Field Day experiments have been published in the peer-reviewed American Geophysical Union journal Radio Science as "Citizen radio science: an analysis of Amateur Radio transmissions with e‐POP RRI" by Dr. Gareth Perry et al. From the plain language summary:
We report the results of an experiment in which we used a satellite‐based radio receiver to eavesdrop on Ham radio communications as the satellite passed over the United States. We identified 14 Ham radio users by their call signs, and used this information to determine their location during the experiment. We were able to identify unique signatures in the Hams' signals that are directly related to the nature of the how the Hams' radio waves traveled through the Earth's ionosphere up to the satellite. Furthermore, we used our knowledge of the position of the spacecraft, and the location of the Hams and their broadcast frequencies to deduce the structure of the Earth's ionosphere over the United States during the experiment. This experiment and its results show that Ham radio transmissions and Hams (amateur radio operators) can be valuable assets in determining the structure of the ionosphere over large geographic regions.
The Canadian CAScade, Smallsat and Ionospheric Polar Explorer (CASSIOPE) spacecraft once again eavesdropped in on the 2018 ARRL Field Day. Onboard CASSIOPE is the Enhanced Polar Outflow Probe (e-POP), a suite of eight science instruments studying spaceweather. The Radio Receiver Instrument (RRI), one of e-POP’s eight instruments, was tuned to 7.005 MHz (40 m), during 6 passes over the North American continent during the Field Day activities. “We’re really happy with our results this year” remarked Dr.