The Earth's geomagnetic field - a key to radio propagation

[TACAIR]

Warning, this will be one of my long-winded posts involving Science and stuff.
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Today, we see, via measurements of multiple scientific instruments, that the Earth's total geomagnetic field is in a state of flux (change). It is growing weaker, with some spots now being quite noticeable (South Atlantic Geomagnetic Anomaly)

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This geomagnetic field interacts with the so-called solar wind in ways still being studied, but this field and the impacts of solar events (flares and CMEs) do produce notable changes in radio propagation. This cause and effect is studied on an hourly basis by multiple instruments - both on the ground and in orbit. (See D Region Absorption Predictions (D-RAP) | NOAA / NWS Space Weather Prediction Center and related products)
This study is owing to impacts to our technology society - from power outages to loss of communications via satellites.
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Part of this ongoing study is a look at past changes int he Geomagnetic field strength thru measurements via archaeointensity. By using known Human artifacts, these measurements can be fairly 'accurate' (used loosely) and provide a longer view of the geomagnetic field and known changes owing to the field variations.
(The strength of the Earth's magnetic field from Pre-Pottery to Pottery Neolithic, Jordan | PNAS)
Concurrent with this is the study of past solar impacts (flares and CMEs) and the level of these events as seen on Earth.
These Miyake Events (mentioned elsewhere) have shown impacts, but these are not well understood owing to the lack of measurements of the events vice the observed impacts (instrumentation vs tree ring carbon uptake).

"Nine such extreme solar storms – known as Miyake Events – have now been identified as having occurred over the last 15,000 years. The most recent confirmed Miyake Events occurred in 993 AD and 774 AD. This newly-identified 14,300-year-old storm is, however, the largest that has ever been found – roughly twice the size of these two.  " (bold added Ed)
(Researchers identify largest ever solar storm in tree rings   | University of Leeds)
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Related to the ~14,500 year mark ( the exact times cannot be certain owing to varieties in dating methods.)
NOAA National Environmental Satellite, Data, and Information Service: Drought and the Ancient Maya Civilization.
"About 14,500 years ago, Earth's climate began to shift from a cold glacial world to a warmer interglacial state. Partway through this transition, temperatures in the Northern Hemisphere suddenly returned to near-glacial conditions. This near-glacial period is called the Younger Dryas, named after a flower (Dryas octopetala) that grows in cold conditions and that became common in Europe during this time. The end of the Younger Dryas, about 11,500 years ago, was particularly abrupt. In Greenland, temperatures rose 10°C (18°F) in a decade (Alley 2000). Other proxy records, including varved lake sediments in Europe, also display these abrupt shifts (Brauer et al. 2008)"
Nearly at the same time, an event caused a massive 'Black Mat' to be deposited across much of Earth.
((PDF) Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling (researchgate.net)) The 'Clovis culture' also disappeared at nearly this exact timeframe. There is still some argument of asteroid strike vs massive solar flare/CME leading to this effect.
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Many ARS operators, can be or are puzzled as to the rapid changes in propagation owing to both geomagnetic field strength and solar impacts. Given that scientists, who have made it a life's work to sort this all out still have their puzzlements should relive any stress as to the cause/effects to propagation -- even the boffins are still working this out.
Since there is nothing that we can do about these planetary-wide effects of earth/solar interactions - perhaps it is best to just work with what we are presented for propagation and not worry over the rest.
That's because there is nothing for us to do for change there either.
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More to follow

[Ever (Zombiepreparation)]

oooo... delicious.

Will be waiting for Moar with excitement!

[TACAIR]

Found another fun article

The Solar Micronova: A Paradigm-Shifting Catastrophic Event | Futurism (vocal.media)
Has this little nuggest
"The galactic current sheet plays a crucial role in the solar micronova event. It delivers both known triggers of nova events—an electric field containing the magnetic reversal point (magnetic kick) and material (ENAs, IPUs, and dust) dumped onto the sun. The solar micronova explains the isotope findings, accounts for the buoyancy of the galactic current sheet, and aligns with ancient stories of the black sun and the solar flash."

This would go a long way to explain the so-called "Black Mat" isotopes found around the world.

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related
Solar 'Superflares' Rocked Earth Less Than 10,000 Years Ago--and Could Strike Again | Scientific American
"The first indication that solar storms could be even worse came in 2012, with the discovery of a mega storm some 10 to 100 times stronger than the Carrington Event that occurred around A.D. 775. "It was really, really astounding," says Nicolas Brehm of ETH Zurich. "We didn't think something of this magnitude could happen."

This article also mentions the Miyake Events (plural)
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Also related - 
Published March 5, 2024 and a news release on the anniversary of the Great Canadia Power Outage of 1989.
Transient Offset in 14C After the Carrington Event Recorded by Polar Tree Rings - Uusitalo - 2024 - Geophysical Research Letters - Wiley Online Library

"Plain Language Summary
Strong Earth-directed solar eruptions can cause 14C concentration spikes in the atmosphere. Large enough events may leave a signal in the annually grown tree-rings as they capture the isotopic carbon fingerprint through photosynthesis. Such rapid 14C increases have been detected, for instance, starting in years 774 and 993 CE. However, no increase has been observed following the Carrington event of 1859, despite it being the largest solar eruption of the modern era. Notably, all prior 14C measurements covering the Carrington event come from mid-latitude trees. To achieve a broader geographical coverage, we have measured the event from several high-latitude locations. After comparing the high- and mid-latitude measurements, we have found a statistically significant difference lasting for several years post-Carrington. To better understand the difference, we have adopted a 14C production and atmospheric transport model capable of simulating regional differences. Despite the improved model, we found it unable to reproduce the observational results, which suggests features beyond current understanding. Ultimately, the observation emphasizes the role of subtle 14C differences in tree-ring 14C studies, potentially opening new ways to study past solar phenomena and atmospheric dynamics."
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The bold-faced part really caught my attention. The 1859 event - the largest **observed** Miyake Event - and the Carbon 14 signature was weak to non-existent in the midlatitudes. Even at higher latitudes, the C14 'signature' lasted several years - something the current Miyake model cannot account for.
The paper highlights this as:
"As a summary, we report a robust observational result of a transient Δ14C offset after the Carrington event. The offset cannot be understood in the framework of the current paradigm, as demonstrated by the modeling results."
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I see many more Master thesis and Doctorial dissertations coming as folks poke at the Miyake-class solar events.
I've linked the entire monograph. While 17 'authors' are listed, this may well be an artifice of the peer review process and funding spread.

Posted for your edification on this interesting solar phenomena.
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From the same Journal:
A 21st Century View of the March 1989 Magnetic Storm - Boteler - 2019 - Space Weather - Wiley Online Library

"On 13 March 1989, the largest magnetic storm of the last century caused widespread effects on power systems including a blackout of the Hydro-Québec system. Since then this event has become the archetypal disturbance for examining the geomagnetic hazard to power systems. However, even 30 years on from 1989, the story of exactly what happened in March 1989 is far from complete. This paper reexamines the information available about the March 1989 event and uses this to construct a timeline and description of the space weather phenomena and how they caused the power system effects."

Happy Anniversary!

Both papers are fully accessible at the links I have provided.