South Atlantic Anomaly

[KW2P]

The South Atlantic Anomaly is an interesting oddity about Earth's magnetic field. I don't see any mention of it on the forum so I thought I'd bring it up.

There are many articles about it on the Internet. Here's one from Science Alert. (Note that Science Alert tries to phrase their stuff in the most alarming / click-bait manner they can. But the factual content of the article is accurate.)

https://www.sciencealert.com/nasa-is-tracking-the-mysterious-evolving-anomaly-in-earth-s-magnetic-field

Mysterious?  It's not that mysterious but it is interesting.

[hamateur 1953]

Click bait?  yes the non russian satellite Iryna42 did show up twice during my reading of the article..  nuff said, mike 

Edited March 25, 2023 by hamateur 1953
punctuation

[KW2P]

It's certainly not click bait. It's been known for a long time.  Here, educate yourself: https://en.wikipedia.org/wiki/South_Atlantic_Anomaly

Also: https://svs.gsfc.nasa.gov/4840

Also: https://www.space.com/south-atlantic-anomaly-11-million-years.html

[Christopher S.]

5 hours ago, hamateur 1953 said:

Click bait?  yes the non russian satellite Iryna42 did show up twice during my reading of the article..  nuff said, mike 

That seems rather rude. There are certainly more polite(and coherent) ways to communicate than this.

 

15 hours ago, KW2P said:

The South Atlantic Anomaly is an interesting oddity about Earth's magnetic field. I don't see any mention of it on the forum so I thought I'd bring it up.

There are many articles about it on the Internet. Here's one from Science Alert. (Note that Science Alert tries to phrase their stuff in the most alarming / click-bait manner they can. But the factual content of the article is accurate.)

https://www.sciencealert.com/nasa-is-tracking-the-mysterious-evolving-anomaly-in-earth-s-magnetic-field

Mysterious?  It's not that mysterious but it is interesting.

Do you have a question about the SAA or this article?

I ask because you've opened and shut the discussion yourself by sharing a clickbait article and concluding its contents to be accurate. That is not a discussion topic, that's just a conclusion you might come to after reading and checking sources. I'd rather not see links to sensationalized blogs in place of pertinent source material for specific aspects of the SAA; moreover, it is unclear what about the SAA interests you, making it a bit of a challenge to come up with relevant responses.

Hopefully, you will remember why you created this topic, and then we'll actually have a premise for discussion. Otherwise, your post doesn't seem to solicit a dialogue nor share new information. We're here for the science and education all the same, but there needs to be opportunity for either to take place.

[Paulo Scaldaferri]

I feel kindda odd how we take some information...

Acually I´ve been pretty worried by some things and not sure if this is the right place to discuss, but taking into consideration that:

- The South Atlantic Anomaly is growing and splitting;

- The Magnetic Pole is shifting faster than before;

- Earth´s core is slowing rotation;

- The Sun has been surprising us with a pretty active cycle that is quite far from expected.

Things are looking just too strange to me overall, with so many signs that big things could happen...

Taking into consideration dendrochronological studies we are due to big solar hits.

Taking paleomagnetic records we are due to a magnetic flip.

I don´t know if everything seems just right to scientists but I feel evidences show big changes are possible and we are experimenting some accelerated processes that we could be denying...

I have to say that I´m no expert in any of those areas, but as a physician I do read a lot, articles, books, and love good science, but I really feel like an outsider here (hope to not look like an intruder and sorry if this is too off-topic).

[Tormentius]

50 minutes ago, Paulo Scaldaferri said:

I feel kindda odd how we take some information...

Acually I´ve been pretty worried by some things and not sure if this is the right place to discuss, but taking into consideration that:

- The South Atlantic Anomaly is growing and splitting;

- The Magnetic Pole is shifting faster than before;

- Earth´s core is slowing rotation;

- The Sun has been surprising us with a pretty active cycle that is quite far from expected.

Things are looking just too strange to me overall, with so many signs that big things could happen...

Taking into consideration dendrochronological studies we are due to big solar hits.

Taking paleomagnetic records we are due to a magnetic flip.

I don´t know if everything seems just right to scientists but I feel evidences show big changes are possible and we are experimenting some accelerated processes that we could be denying...

I have to say that I´m no expert in any of those areas, but as a physician I do read a lot, articles, books, and love good science, but I really feel like an outsider here (hope to not look like an intruder and sorry if this is too off-topic).

Thanks for sharing these thoughts. As far as the South Atlantic Anomaly goes, it is not settled and there is evidence to suggest that it has been around for centuries so many scientists believe that it’s not related to the magnetic fields.

In regards to the magnetic field, it has been moving faster but that in and of itself doesn’t mean anything. The magnetic field is unpredictable, is actually stronger than it’s historical average and could very well move in the opposite direction, there’s no way to tell if that’s the case.

There are some who claim that we’re overdue for a magnetic reversal because it has been 90,000 years, but that is not completely accurate. The field has apparently gone for millions of years without having a shift. The term overdue with natural calamities is misleading because these events don’t operate on a schedule. They are just estimates and we are not 100 percent sure whether they are accurate.

As for the Earth’s rotation slowing, that is something that’s been taken completely out of context. This is based on a single study from a Chinese university that has not been peer reviewed which suggests that the Earth’s core shifts rotation every couple of decades, so it’s just a natural phenomenon.

So a bunch of clickbait articles ran with it and took it way out of context. First of all, it hasn’t been peer reviewed so we don’t know if it’s true. Second of all, if it is true, it’s just a natural phenomenon that happens every couple of decades, not an apocalyptic event.

In regards to the Sun being very active, it’s not that much more active than expected. Even Dr McIntosh, the one who most famously pushed the idea of a large cycle thinks that it’s going to be around the historical average so hardly anything we haven’t seen.

As far as us being due for big solar storms, again you have to remember that these events don’t have a schedule, they’re just estimates. San Francisco has been ‘overdue’ for a large earthquake for decades and nothing has happened yet. These estimates help us have an idea of how frequent these events are but they have to be taken with a grain of salt because just because something is thought to happen once a century doesn’t mean that it will.

There are some scientists who think that we’ve had our big flare for the cycle because of the recent far side event. Now we don’t know for sure but there are some who think that is very likely.

So hope that helped alleviate your fears. Most heliophysicists are far more worried about terrestrial disasters than ones from the Sun. To quote Dr Erika Palmerio in regards to the Sun ‘We have to monitor the Sun and we have to be prepared but we do not need to lose sleep over it.’

[Paulo Scaldaferri]

Thank you a lot for those explanations!

[hamateur 1953]

22 hours ago, KW2P said:

It's certainly not click bait. It's been known for a long time.  Here, educate yourself: https://en.wikipedia.org/wiki/South_Atlantic_Anomaly

Also: https://svs.gsfc.nasa.gov/4840

Also: https://www.space.com/south-atlantic-anomaly-11-million-years.html

definitely not. I was only referring to an unfortunate ad that accompanied the posting.  Misunderstood your admonition I guess. apologies OM.  However it was instructive to me in that from now on when I joke about something, I must add jk at the end of it!   Perhaps at least one individual clearly “ didn’t get it”. perhaps you as well.  You have my sincere apologies.  Mike.   And as far as education, I’ve learned more here in the last two some years than in my prior 68 some.  Always continue to learn.  Love this site btw    By all means KW2P please feel free to pm me directly for a clarification as it really doesn’t belong on public display I feel. 73. 

Edited March 26, 2023 by hamateur 1953
addendum

[Philalethes]

3 hours ago, Paulo Scaldaferri said:

Things are looking just too strange to me overall, with so many signs that big things could happen...

Well, the thing is, the amount of time we have reliable recorded measurements of any of those variables is extremely small compared to the scales of time they tend to vary significantly over.

For example, this study found evidence suggesting that there's been anomalous geomagnetic behavior in that region (that we now know as the SAA) for at least as long as 8-11 million years, spanning numerous geomagnetic field reversals, and so is unlikely to be a harbinger of such.

And as for the magnetic field of Earth weakening, that's also typically often taken out of context (I was bamboozled by this myself before looking more into it), typically neglecting to mention some of the facts presented in this article, such as that the field is rather back to where it was 4000 years ago after having had a rapid increase, and stronger than it was for the 8000 years preceding that, as well as generally being in the upper range of what it's assumed to have been for the past 2 million years.

Then when it comes to current Solar cycle, it's really just relatively more active compared to predictions of almost historical lows (apart from grand minima), but still not very active overall compared to some of the cycles we've seen in even recent times; and even if it had somehow ended up matching those cycles, that in itself wouldn't really make it possible to conclude that anything extraordinary was going on, again given the short time we've actually recorded Solar activity in a reliable manner, because for all we know that could have been what one would expect on the longer timescales we don't have a good overview of.

So in my view there definitely doesn't seem to be anything out of the ordinary in terms of those activities at all, and there'd have to be far more movement much more abruptly in those variables for there to be any concern about any accelerating trends; that's not to say it couldn't happen, but so far I would not say there is any sign of it.

[KW2P]

4 hours ago, hamateur 1953 said:

definitely not. I was only referring to an unfortunate ad that accompanied the posting.  Misunderstood your admonition I guess. apologies OM.  However it was instructive to me in that from now on when I joke about something, I must add jk at the end of it!   Perhaps at least one individual clearly “ didn’t get it”. perhaps you as well.  You have my sincere apologies.  Mike.   And as far as education, I’ve learned more here in the last two some years than in my prior 68 some.  Always continue to learn.  Love this site btw    By all means KW2P please feel free to pm me directly for a clarification as it really doesn’t belong on public display I feel. 73. 

Christopher is quite right. I was in a hurry and framed my response in a rude manner, for which I'm sorry.

And sorry for the delay in responding. I just got home from working consecutive 12 hour shifts. I tend to disappear Fridays and Saturdays.

23 hours ago, Christopher S. said:

That seems rather rude. There are certainly more polite(and coherent) ways to communicate than this.

 

Do you have a question about the SAA or this article?

I ask because you've opened and shut the discussion yourself by sharing a clickbait article and concluding its contents to be accurate. That is not a discussion topic, that's just a conclusion you might come to after reading and checking sources. I'd rather not see links to sensationalized blogs in place of pertinent source material for specific aspects of the SAA; moreover, it is unclear what about the SAA interests you, making it a bit of a challenge to come up with relevant responses.

Hopefully, you will remember why you created this topic, and then we'll actually have a premise for discussion. Otherwise, your post doesn't seem to solicit a dialogue nor share new information. We're here for the science and education all the same, but there needs to be opportunity for either to take place.

Hello Christopher. My intention was to stimulate discussion about an interesting topic I've never seen discussed on the forum.

The article I chose to get things going isn't click bait. Nothing in the article is factually wrong or off-topic but it is worded in a sensationalist manner. Click bait would be a misleading title that leads to an article that's off-topic or which contradicts the title. The article I chose sounds like click bait but then one finds an article that's on topic and factually correct. It's just written in a sensationalist manner.

[hamateur 1953]

Thanks for clarifying that. I was going to mention that as you were formerly stationed along with Yeager  as I recall. I unfortunately have some bad news to relay. EX Air Force  WW passed away two weeks ago following a protracted illness.  Don’t know if you had heard yet but enough time has passed people  are likely to begin to wonder,.  73  Mike N7ORL

Edited March 26, 2023 by hamateur 1953

[Paulo Scaldaferri]

7 hours ago, Tormentius said:

In regards to the magnetic field, it has been moving faster but that in and of itself doesn’t mean anything.

This article authors (Robert Coe and Pierre Camps) believe the latest shift could have happened over a faster period of time:

https://www.researchgate.net/publication/236622936_New_evidence_for_extraordinary_rapid_change_of_the_geomagnetic_field_during_a_reversal

[Newbie]

On 3/26/2023 at 6:18 PM, hamateur 1953 said:

Thanks for clarifying that. I was going to mention that as you were formerly stationed along with Yeager  as I recall. I unfortunately have some bad news to relay. EX Air Force  WW passed away two weeks ago following a protracted illness.  Don’t know if you had heard yet but enough time has passed people  are likely to begin to wonder,.  73  Mike N7ORL

Vale WildWill,

May you rest in Peace!

Suffering no longer!

Newbie

[KW2P]

On 3/25/2023 at 9:35 PM, hamateur 1953 said:

definitely not. I was only referring to an unfortunate ad that accompanied the posting.  Misunderstood your admonition I guess. apologies OM.  However it was instructive to me in that from now on when I joke about something, I must add jk at the end of it!   Perhaps at least one individual clearly “ didn’t get it”. perhaps you as well.  You have my sincere apologies.  Mike.   And as far as education, I’ve learned more here in the last two some years than in my prior 68 some.  Always continue to learn.  Love this site btw    By all means KW2P please feel free to pm me directly for a clarification as it really doesn’t belong on public display I feel. 73. 

Understood.  It sounded like you were dissing the whole subject.  And I admit there was a bit of a trick there. The article sounds like click-bait but isn't.

As far as ads, well, I don't look at ads. My brain learned long ago to follow the text only and ignore/skip all ads. I have no idea what ads are on that article or even if there are ads. I would expect bad and deceptive ads on that page since they intentionally sensationalize science.

[hamateur 1953]

A clickbait reference by myself six months ago may very well have offended @MinYoongi cuz she posted CME on the boards!  pulling me immediately off of solarham. No sweat guy!  My point being that I was a bit irritated and acted hastily without thinking of the impact that it might have upon the recipient ( victim) 

Edited March 27, 2023 by hamateur 1953
clarity

[Paulo Scaldaferri]

On 3/25/2023 at 10:05 PM, Tormentius said:

these events don’t operate on a schedule.

I read some articles that claim they may occur pretty regularly, but in a centenary scale… eg for SAP events:

https://www.aanda.org/articles/aa/pdf/2018/07/aa31892-17.pdf

Edited March 28, 2023 by Paulo Scaldaferri
Added info

[Sam Warfel]

On 3/25/2023 at 11:12 PM, Philalethes Bythos said:

For example, this study found evidence suggesting that there's been anomalous geomagnetic behavior in that region (that we now know as the SAA) for at least as long as 8-11 million years, spanning numerous geomagnetic field reversals, and so is unlikely to be a harbinger of such

Thanks for posting that, I’m familiar with the SAA but hadn’t heard that particular detail about how it may be a very long lived feature.

[Paulo Scaldaferri]

12 hours ago, Sam Warfel said:

Thanks for posting that, I’m familiar with the SAA but hadn’t heard that particular detail about how it may be a very long lived feature.

It seems to me that the simple presence of the SAA and the conclusion that it does not interfere with magnetic excursions is questionable. This study by Nilsson et al (it even cites the previous one) considers that the western movement of the SAA seems to be associated with dipole movement. In a centenary scenario it could even strengthen the dipole after all…

“Our results suggest that there are millennial-scale periodicities in the variation of the DM over the past 9,000 y and that these are related to a recurrent pattern of field asymmetries, similar to the present-day SAA.”

[Philalethes]

19 minutes ago, Paulo Scaldaferri said:

It seems to me that the simple presence of the SAA and the conclusion that it does not interfere with magnetic excursions is questionable. This study by Nilsson et al (it even cites the previous one) considers that the western movement of the SAA seems to be associated with dipole movement. In a centenary scenario it could even strengthen the dipole after all…

“Our results suggest that there are millennial-scale periodicities in the variation of the DM over the past 9,000 y and that these are related to a recurrent pattern of field asymmetries, similar to the present-day SAA.”

As per their own paper, i.e. the one you just posted, that doesn't have anything to do with excursions, which are much rarer events (the current amount of polar drift and geomagnetic weakening is nowhere close to being considered an excursion), and certainly not anything to do with full-blown reversals, which are even rarer. In fact, there's nothing about what they write that seems incompatible with what I posted above as far as I can see; to the contrary, it seems to echo exactly that sentiment, namely that it's a recurring anomaly (and has been for at least 8-11 million years). As you just said yourself, and as they write in the article, it is likely to disappear again along with the field strengthening (and to then reappear again in the future):

Quote

The analogy implies that the South Atlantic Anomaly will likely disappear in next few hundred years, accompanied by a return to a more symmetric field configuration and possibly, a strengthening of the axial dipole field.

Perhaps I'm missing what you're arguing here, but what Tormentius was talking about earlier when talking about such events not being on schedule was geomagnetic field reversals. This is also readily seen in the geologic record as e.g. presented in the article I linked to above (this), where you can see how irregular the pattern of reversals is:

[Paulo Scaldaferri]

21 minutes ago, Philalethes Bythos said:

As per their own paper, i.e. the one you just posted, that doesn't have anything to do with excursions, which are much rarer events (the current amount of polar drift and geomagnetic weakening is nowhere close to being considered an excursion), and certainly not anything to do with full-blown reversals, which are even rarer. In fact, there's nothing about what they write that seems incompatible with what I posted above as far as I can see; to the contrary, it seems to echo exactly that sentiment, namely that it's a recurring anomaly (and has been for at least 8-11 million years). As you just said yourself, and as they write in the article, it is likely to disappear again along with the field strengthening (and to then reappear again in the future):

Perhaps I'm missing what you're arguing here, but what Tormentius was talking about earlier when talking about such events not being on schedule was geomagnetic field reversals. This is also readily seen in the geologic record as e.g. presented in the article I linked to above (this), where you can see how irregular the pattern of reversals is:

My point is just the fact that it seems they may influence (or be influenced by) dipole movement. For inversions, excursions, we do not actually know how it behaved (instead of we know it did not change). 

[Philalethes]

45 minutes ago, Paulo Scaldaferri said:

My point is just the fact that it seems they may influence (or be influenced by) dipole movement.

I'm not sure if that's really the correct conceptualization, as far as I understand it at least. The way I understand it the SAA seems to be not so much influenced by the dipole moment variation as it seems to be a regular part of that variation itself. That is what the paper you referred to was arguing, i.e. that this is a periodic variation within the overall variation, and that when this internal period is at its minimum, the SAA appears.

52 minutes ago, Paulo Scaldaferri said:

For inversions, excursions, we do not actually know how it behaved (instead of we know it did not change). 

But the evidence suggests, as per that very article, that the variation is regular and occurs over a much smaller period of time than excursions and reversals; and as per the paper I referenced earlier this seems to have been occurring for millions of years.

In other words it seems to me that no matter how you square it there's no way of construing the appearance of the SAA as somehow heralding "big changes" and "accelerating processes" as you suggested earlier; the evidence, including what you yourself are posting, is indicating the exact opposite.

[David Silver]

I mean, it says very clearly, not in our lifetime:

Quote

the field seems to have been stronger, on average, since the last reversal, which might explain why this current polarity interval has lasted longer than the preceding ones.
The other interesting thing about this record is that the field has behaved in quite a consistent way during every reversal. In the figure below, Valet et al. plot the changes in field intensity across each individual change in polarity atop one another, with time decreasing from right to left. In each case, the reversal is preceded by at least 20,000-40,000 years of fairly continuous decay in field strength to about the same (very low) value, with a much more rapid recovery in field strength following the transition. In this context, a couple of centuries’ worth of field decay is not particularly significant, especially since the present field strength (about 8 on the scale in this figure) is still a lot higher than the value reached during all of these reversals