HAMNET Report 2nd August 2020

The ARRL has reported that the Hurricane Watch Net (HWN) activated for Hurricane Hanna, the first hurricane of the Atlantic Hurricane season. The storm was poised to make landfall along the Gulf of Mexico. A Category 1 storm, Hanna had maximum sustained winds of 120 km/h. At the time of the report, the storm was about 90 miles east-northeast of Port Mansfield, Texas, and about 100 miles east-southeast of Corpus Christi, Texas.

WX4NHC at the NHC also activated for Hanna, and participated in the HWN on 14.325 MHz, as well as on the VoIP Weather Net .

Bobby Graves KB5HAV said “We are also available to provide back-up communication to official agencies such as emergency operations centres, Red Cross officials, and storm shelters in the affected area. We will also be interested to collect and report significant damage assessment and storm surge data back to the forecasters as well as to FEMA officials stationed in the National Hurricane Centre.”

Due to COVID-19 precautions, WX4NHC operators are operating from their homes.

Meanwhile, there is an orange alert for another Hurricane named Isaias-20, active in the Atlantic, and approaching the Caribbean, predicted to proceed up the East coast of Florida towards the Carolinas. With current maximum wind speeds of about 140 km/h, it is currently threatening all the Caribbean islands and Florida. It is to be expected, though not yet reported, that the National Hurricane Centre will remain on standby, monitoring the path of the storm, and activating WX4NHC if amateur radio is called upon for weather reports and message handling.

The ARRL Letter this week reports that the airship Dirigible Italia crashed on pack ice northeast of the Svalbard Islands on 25th May 1928, on the return leg of a trip to survey the North Pole with 16 passengers and crew on board. At impact, one person was killed, and the cabin carrying nine people separated from the hydrogen-filled airframe. Six crew members on the dirigible structure were never seen again, after the airship again became airborne. The survivors on the icepack turned to their 5 W wireless set, a one-tube Hartley oscillator, to put out a call for help, but it was only after 9 days of trying that they were able to get the attention of a radio amateur 1,900 kilometres away.

The recently published article, “The Shipwreck of the Airship Dirigibile Italia in the 1928 Polar Venture: A Retrospective Analysis of the Ionospheric and Geomagnetic Conditions,” provides the gripping historical context and tries to explain why it was so difficult to establish communication for a rescue. Drawing from sources of geophysical data collected at the time, and using modern theories of propagation — including some directly derived from amateur radio observations — the authors present data including sunspot count, magnetic flux, and F2 layer height, and take the reader through an analysis of the sky-wave and ground-wave paths.

Ultimately, the authors suggest, ground-wave path losses likely exceeded 100 dB, leaving only skywave as a potential link. In the first few days after the crash, the ionospheric path was impossible at the frequencies being used — 9.1 and 9.4 MHz — due to disturbed conditions. It was only after conditions had settled that communication became possible, and it only became reliable when a lower frequency was chosen.

Even after communication was established, 15 rescuers were lost in the search and recovery operations, including Roald Amundsen, Norway’s famed polar explorer. Finally, on July 12, 1928, 48 days after the initial crash, a Russian icebreaker was able to reach and rescue the survivors.

Propagation conditions really can become a matter of life or death.

Further, Tech Explorist tells us that Solar flares are an explosion of energy caused by tangling, crossing, or reorganizing of magnetic field lines near sunspots. Solar flares release a lot of radiation into space. If a solar flare is very intense, the radiation it releases can interfere with our radio communications here on Earth.

The X-ray light emitted by a flare, and the ejection of material from the Sun that often accompanies them can produce powerful space weather effects on Earth. These can pose hazards to astronauts, spacecraft, and technological systems on the ground, such as electric power grids and radio communications.

As global society turns out to be more dependent on these technologies, there is an increasing need for reliable techniques to anticipate imminent solar events and improve cautioning times when they happen. In spite of many years of study and near persistent monitoring of the sun’s magnetic activity, the specific conditions and mechanisms that produce flares remain unknown, making them especially difficult to gauge.

Kanya Kusano and colleagues presented a new model called ‘κ-scheme (kappa-scheme) to forecast large solar flares more reliably than previous methods. This physics-based scheme predicts when a large solar flare is imminent using routine magnetic observations of the Sun.

It derives critical thresholds of a magneto-hydrodynamic instability. It also identifies where the flare will occur and how much energy could be released.

Scientists tested the model by analysing data from NASA’s Solar Dynamics Observatory from 2008 to 2019, finding that the κ-scheme was able to identify the occurrence, location, and size of most large flares, up to 20 hours in advance.

Finally, Sue Kerr, writing in The Leader-Vindicator, says that as a senior citizen, she tends to stick close to home. She’s not a coward, far from it, but she just doesn’t feel like picking up the coronavirus and sharing it with her frail family members.

As a result, there’s more tinkering going on. She’d like to improve her soldering skills, she’d like to play around with amateur radio and there are all kinds of nifty and useful things that she (an average person) can make.

She says lifelong learning is not limited to the so-called smart people. It’s only a matter of scratching our curiosity itch. And it’s good for us.

She says COVID-19 has made us change the way we do some things. Before it hit, she’d never been in a Zoom teleconference. It sure works better for her than the out-of-date software she had to use for a freelancing gig back in 2013.

So, this creepy little virus has us doing things in new ways. If we’re wishing and praying for things to get back to normal, we should consider the possibility that the new normal might actually be better — simpler, more convenient, maybe even less expensive.

Thank you for the perspective, Sue!

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.