HAMNET Report 31st March 2024

When this report was being written, Tropical Cyclone GAMANE was crossing northern Madagascar and weakening, and on 28 March at 0.00 (UTC), its centre was located inland over the Andapa District area, Sava Region with maximum sustained winds of 45 km/h as a tropical depression.

According to media reports, heavy rainfall and floods had affected the regions of Sava, Diana Sofia, Analanjirofo, Alaotra Mangoro and Atsinanana and resulted in six fatalities, one person still missing and more than 2,600 people affected negatively. 

GAMANE was forecast to move southeast still inland and to go towards the sea, south of Masoala Peninsula on 28th March in the evening. 

For the following 24 hours, moderate to very heavy rainfall and strong winds were still forecast over northern, north-eastern and central-eastern Madagascar.

Last weekend’s level 4 geomagnetic storm as a result of two simultaneous solar flares and coronal mass ejections (CME) off the sun both aimed directly at us, must surely rank as one of the most severe we have experienced in the last 10-15 years. Your author cannot recall seeing a Planetary K index of 8, as it was last Sunday at 18h00 UTC, in the last 30 years, and it was definitely an evening to turn off the HF radio, because the bands were completely dead, and to go back to my knitting!

Luckily, the K index had settled down again within 24 hours, and the bands were open again by Tuesday. The two large offending sunspot regions are rotating off our side of the sun, but this kind of disruption is to be expected again as we close in on the peak of solar cycle 25.

In fact on Sunday 28th March, an M7.1 solar flare, followed later in the day by an X1.1 flare and a CME, were released from that sunspot group 3615, the origin of one of last Saturday’s 2 CME’s, but 3615 was far enough rotated to the west of the Sun’s face not to have any effect on our ionosphere.

I’m sure those people living at high latitudes, and who like looking at Auroras had nothing to complain about last Sunday and Monday nights. The geomagnetic storm must have put on a display worth watching.

NASA has added a dimension to the study of the ionosphere during next Monday’s eclipse of the sun, with a plan to launch three instrument-laden sounding rockets on April 8, with the goal of studying how the temporary blocking of sunlight affects part of the upper atmosphere.

The sounding rockets will each blast off from the space agency’s Wallops Flight Facility, one 45 minutes before, one during, and the last 45 minutes after the local peak eclipse.

The trio will soar into the ionosphere, a region 55 to 310 miles above the Earth’s surface where, in the day, particles are electrically charged, or “ionized,” by radiation from the sun.

“It’s an electrified region that reflects and refracts radio signals, and also impacts satellite communications as the signals pass through,” explained mission leader and engineering physicist professor Aroh Barjatya, of Florida’s Embry-Riddle Aeronautical University, in a statement.

At night, the ionosphere thins out as electrons and ions relax and recombine back into neutral atoms, only to separate again the next day.

A solar eclipse creates, in effect, a temporary, localized night—causing the local temperature and ionospheric density to drop and then rise again.

In this way, the passage of the moon’s shadow across the Earth triggers both large-scale atmospheric waves and smaller-scale disturbances that have the potential to interfere with radio communications passing through the ionosphere.

At the same time, the ionosphere can be disrupted by both regular weather and its space-based counterpart.

“Understanding the ionosphere and developing models to help us predict disturbances is crucial to making sure our increasingly communication-dependent world operates smoothly,” Barjatya added.

He told Newsweek: “Sounding rockets will help us study if, when, where, and why small-scale perturbations happen due to sudden reduction in solar radiation and/or due to meteorological changes brought on by the eclipse shadow.

Thank you to newsweek.com for this report.

Here is some interesting research. Writing in Phys.org, David Appell asks whether it could be that human existence depends on gravitational waves. Some key elements in our biological makeup may come from astrophysical events that occur because gravitational waves exist, a research team headed by John R. Ellis of Kings College London suggests.

In particular, Iodine and Bromine are found on Earth thanks to a particular nuclear process that happens when neutron stars collide. In turn, orbiting neutron star pairs spiral in and collide due to their emissions of energy in the form of gravitational waves. There may thus be a direct path from the existence of gravitational waves to the existence of mammals.

Humans are mostly made up of hydrogen, carbon and oxygen, with many additional trace elements. (There are in fact 20 elements essential to human life.) Those elements with an atomic number less than 35 are produced in supernovae, implosions of stars that have exhausted their nuclear fuel and collapsed inward. The implosion/collapse results in a [surface] explosion that spews their atoms all over the universe.

But two elements are provided by other means—Iodine, needed in key hormones produced by the thyroid, and Bromine, used to create collagen scaffolds in tissue development and architecture.

Thorium and uranium have been indirectly important for human life, as their radioactive decays in Earth’s interior heat the lithosphere and allow tectonic activity. The movement of tectonic plates removes and submerges carbon from the crust of the planet, which is itself removed from the atmosphere via water reacting with carbon dioxide and silicates, avoiding the possibility of a runaway greenhouse effect like has happened on Venus.

About half the heavy elemental atoms on Earth (heavier than iron) are produced by what’s known as the “r-process”—the rapid neutron-capture process [too technical to go into here]. The paper concludes that the iodine essential for human life was “probably produced by the r-process in the collisions of neutron stars that were induced by the emissions of gravitational waves, as well as other essential heavy elements.”

“Neutron star collisions occur because binary systems lose energy by emitting gravitational waves,” said Ellis, “so these fundamental physics phenomena may have made human life possible.”

Their paper, “Do we owe our existence to gravitational waves?” is available on the arXiv preprint server.

It appears that the deeper we research, and the more we learn, the more we realise we don’t know.

I’d like to end by wishing a very Happy Easter to all for whom this time is meaningful.

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