What are Miyake events ?

[Mogh, Lord of Blood]

All i know about it's somehow related to Solar storm, i seek an little explanation, thank you in advance for your time 

[Vancanneyt Sander]

A bit of Googling brought this article up that explains what it is: https://www.sciencetimes.com/articles/40702/20221026/miyake-event-tree-rings-tell-next-solar-storm.htm

[Archmonoth]

15 hours ago, Mogh, Lord of Blood said:

All i know about it's somehow related to Solar storm, i seek an little explanation, thank you in advance for your time 

You might enjoy reading about multiple solar storms here: List of solar storms - Wikipedia

 

The event is 1 of many events in the cosmic history of our neighborhood. What exactly would you like explained?

 

 

[Trestan]

Miyake events are short-term, global variations in radioisotope production rates that have been identified in cosmogenic-isotope records.

On 11/29/2022 at 11:11 AM, Vancanneyt Sander said:

A bit of Googling brought this article up that explains what it is: https://www.sciencetimes.com/articles/40702/20221026/miyake-event-tree-rings-tell-next-solar-storm.htm

This article (and by extension, this article from the AAAS that is cited) is somewhat misleading in my opinion. It is common consensus that Miyake events are the result of extreme SEPs, not solar flares as is stated.

[Vancanneyt Sander]

1 uur terug, Trestan zei:

It is common consensus that Miyake events are the result of extreme SEPs, not solar flares as is stated.

Strong SEP events originate from solar flares. Strong long duration solar flares can initiate these solar proton events. For example the X17 in October 2003 was a very strong SEP event. 

[Trestan]

20 minutes ago, Vancanneyt Sander said:

Strong SEP events originate from solar flares. Strong long duration solar flares can initiate these solar proton events. For example the X17 in October 2003 was a very strong SEP event. 

SEP events do not originate from solar flares. They can originate from magnetic reconnection during solar jets (impulsive SEP events) and from CME/IP shocks (gradual SEP events). The latter produce much stronger, longer-duration events.

Historically, flares were thought to be the origin of SEP events, however, consensus changed in the 90s. This view that SEP events result from flares was known as the "solar flare myth". I would like to share a relevant quote about this from D. V. Reames:

Quote

[T]he term "flare" evokes the idea of limited spatial and temporal extent. Historically, the idea of flares as point sources of large SEP events led to a profound misunderstanding of the physics of particle acceleration and transport that persisted for 30 years. Flares last for hours, at most, but large SEP events last for days. Flares are also confined to a few degrees on the Sun but large SEP events (and interplanetary shocks) are seen over a span of ~180°, sometimes more. Early workers proposed that the unseen hand of "coronal diffusion" somehow transported particles uniformly across magnetic field lines to distant longitudes where slow "leakage" from the corona and intense scattering on interplanetary turbulence trapped them for days (often until just after the time of shock passage). Only recently have we understood that the shocks from CMEs cross field lines to accelerate the particles locally over vast regions of space and for long intervals of time in the largest SEP events [see Reames 1993, 1994, 1995].

[Archmonoth]

16 hours ago, Trestan said:

SEP events do not originate from solar flares. They can originate from magnetic reconnection during solar jets (impulsive SEP events) and from CME/IP shocks (gradual SEP events). The latter produce much stronger, longer-duration events.

Historically, flares were thought to be the origin of SEP events, however, consensus changed in the 90s. This view that SEP events result from flares was known as the "solar flare myth". I would like to share a relevant quote about this from D. V. Reames:

I don't disagree that SEPs can come from non-flares, but flares do produce Solar Particle Events. The energy from the flare is released into the surrounding particles and energizes them. Where does the energy go from the flares? 

 

I disagree with the linked article, I don't think "...the idea of flares as point sources of large SEP events led to a profound misunderstanding of the physics of particle acceleration and transport that persisted for 30 years. "

 

How are flares as a point of solar events a "profound misunderstanding"?

[Trestan]

5 hours ago, Archmonoth said:

I don't disagree that SEPs can come from non-flares, but flares do produce Solar Particle Events. The energy from the flare is released into the surrounding particles and energizes them. Where does the energy go from the flares?

You have it backwards. SEPs--that is, solar energetic particles--cause solar flares. The SEPs in this case are particles that have been accelerated, or "energized" as you put it, by magnetic reconnection and confined within closed magnetic loops. These trapped SEPs dissipate their energy through heating and expansion of the loop. The resultant emission of electromagnetic radiation is a solar flare. The SEPs, however, are confined to the loop and do not escape into interplanetary space where they would be able to cause an SEP event.

(Impulsive) SEP events, on the other hand, are caused by SEPs that are accelerated by magnetic reconnection along open magnetic field lines, such as those in solar jets. The SEPs can then escape into interplanetary space where they would be capable of causing an (impulsive) SEP event.

4 hours ago, Archmonoth said:

I disagree with the linked article, I don't think "...the idea of flares as point sources of large SEP events led to a profound misunderstanding of the physics of particle acceleration and transport that persisted for 30 years. "

 

How are flares as a point of solar events a "profound misunderstanding"?

Why do you disagree? I think the author of the article explains why this was a "profound misunderstanding" clearly.

[David Silver]

We discussed this to a similar degree. The answer is that we don’t know yet why it seems that gigantic radiation storms hit the Earth every 1000 years or so. But scientists have been studying it for decades, so it’s better to read their research, data and insight, rather than ‘internet-guy’ opinions:

 

[Archmonoth]

18 hours ago, Trestan said:

You have it backwards. SEPs--that is, solar energetic particles--cause solar flares. The SEPs in this case are particles that have been accelerated, or "energized" as you put it, by magnetic reconnection and confined within closed magnetic loops.

I don't discount multiple causes of flares, but flares are not solely caused by SEPs. There are internal dynamics of the Sun which result in pressures and buildup of magnetic forces. 

 

Solar flares occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles into the surrounding plasma. This isn't my opinion; this is a basic description of flares. 

 

18 hours ago, Trestan said:

These trapped SEPs dissipate their energy through heating and expansion of the loop. The resultant emission of electromagnetic radiation is a solar flare. The SEPs, however, are confined to the loop and do not escape into interplanetary space where they would be able to cause an SEP event. 

So how does the SEP cause flares? 

18 hours ago, Trestan said:

Why do you disagree? I think the author of the article explains why this was a "profound misunderstanding" clearly.

Because learning about addition causes and details of a system doesn't mean there was a "profound misunderstanding" when the previous information is still accurate. (Flares are also caused by internal solar dynamics.)

 

6 hours ago, David Silver said:

We discussed this to a similar degree. The answer is that we don’t know yet why it seems that gigantic radiation storms hit the Earth every 1000 years or so.

Sometimes considerably more often and sometimes considerably less often. 

 

There were 4 carbon-14 spikes from 700-1200 CE, and none from 7176-5410 BCE and none from 5295 BCE to 660 BCE. (4600 years without any event)

 

6 hours ago, David Silver said:

But scientists have been studying it for decades, so it’s better to read their research, data and insight, rather than ‘internet-guy’ opinions:

It's a conversation about an article. Does is bother you to see someone disagree with an article? 

Edited December 5, 2022 by Archmonoth

[David Silver]

Articles are helpful for a “pop science” overview, but I personally seek the source data for this sort of thing. SOMEthing significant happened, and I hope to read further updates on the science.
Royal Society of London:

Quote

 

The wide consensus of the literature is that these events have a solar origin, beginning with Melott & Thomas [43]; Usoskin et al. [44]. For example, the events could represent a solar magnetic collapse, a very brief grand solar minimum, with the reduced heliospheric shielding exposing the Earth to an increase in galactic cosmic rays [45]. Alternatively, and more popular in the literature, the Miyake events could represent the extreme tail of a distribution of solar flares continuous with those that are observed astrophysically on the modern Sun and other solar-like stars. We are fortunate that 14C 14C is not the only cosmogenic isotope that can trace these events: we see evidence of the 774 CE and 993 CE events in time series of 10Be 10Beand 36Cl 36Cl from ice cores [46,47], and because the production of these isotopes depends on input particle energy, they can be used to infer a particle energy spectrumsimilar to solar energetic protons [48]. Only the most energetic particles produce 10Be 10Be , but 36Cl 36Cl isexpected to be produced at comparatively low energies and may therefore shed light on other events as well [49].

 

Edited December 6, 2022 by David Silver

[Trestan]

6 hours ago, Archmonoth said:

I don't discount multiple causes of flares, but flares are not solely caused by SEPs. There are internal dynamics of the Sun which result in pressures and buildup of magnetic forces. 

 

Solar flares occur when stored magnetic energy in the Sun's atmosphere accelerates charged particles into the surrounding plasma. This isn't my opinion; this is a basic description of flares.

I agree entirely here. SEPs are not the sole cause of flares; however, they are a necessary part of the process. The stressed magnetic field alone does not emit electromagnetic (EM) radiation. (When I use the term "flare", I am referring to this emission of EM radiation.)

6 hours ago, Archmonoth said:

So how does the SEP cause flares?

Energy is transferred from the stressed magnetic field to the particles in the loop via magnetic reconnection. These high-energy particles--SEPs--collide with and heat the loop plasma, which results in the emission of EM radiation from both the decelerated SEPs and heated plasma. This EM radiation is what we see as a flare. (The process I am describing here are in reality much more complex.)

7 hours ago, Archmonoth said:

Because learning about addition causes and details of a system doesn't mean there was a "profound misunderstanding" when the previous information is still accurate. (Flares are also caused by internal solar dynamics.)

The misunderstanding is more so about the source of SEP events. Large (gradual) SEP events were misinterpreted as originating in solar flares when they can be better described as having originated in CME/IP shocks. It is profound because this interpretation was held onto for around 30 years.