Earth's magnetic field is not about to reverse

[beecee]

Earth's magnetic field is not about to reverse, study finds

April 30, 2018, University of Liverpool

A study of the most recent near-reversals of the Earth's magnetic field by an international team of researchers, including the University of Liverpool, has found it is unlikely that such an event will take place anytime soon.

There has been speculation that the Earth's geomagnetic fields may be about to reverse , with substantial implications, due to a weakening of the magnetic field over at least the last two hundred years, combined with the expansion of an identified weak area in the Earth's magnetic field called the South Atlantic Anomaly, which stretches from Chile to Zimbabwe.

Read more at: https://phys.org/news/2018-04-earth-magnetic-field-reverse.html#jCp

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the paper:

http://www.pnas.org/content/early/2018/04/24/1722110115

Abstract

The geomagnetic field has been decaying at a rate of ∼∼5% per century from at least 1840, with indirect observations suggesting a decay since 1600 or even earlier. This has led to the assertion that the geomagnetic field may be undergoing a reversal or an excursion. We have derived a model of the geomagnetic field spanning 30–50 ka, constructed to study the behavior of the two most recent excursions: the Laschamp and Mono Lake, centered at 41 and 34 ka, respectively. Here, we show that neither excursion demonstrates field evolution similar to current changes in the geomagnetic field. At earlier times, centered at 49 and 46 ka, the field is comparable to today’s field, with an intensity structure similar to today’s South Atlantic Anomaly (SAA); however, neither of these SAA-like fields develop into an excursion or reversal. This suggests that the current weakened field will also recover without an extreme event such as an excursion or reversal. The SAA-like field structure at 46 ka appears to be coeval with published increases in geomagnetically modulated beryllium and chlorine nuclide production, despite the global dipole field not weakening significantly in our model during this time. This agreement suggests a greater complexity in the relationship between cosmogenic nuclide production and the geomagnetic field than is commonly assumed.

[T. McGrath]

That is good news for the current generation.  At least we will be spared being further irradiated by a weakening magnetic field (assuming a Carrington Event is not in our immediate future).  Magnetic north is continuing to migrate across northern Canada towards Siberia at a rate of between 55 and 60 km per year, but nobody uses compasses any more.  Compasses are so last century technology.  With GPS who cares where magnetic north is located or where it goes?

[Velocity_Boy]

Here's a cool, accessible, light hearted even slightly humorous article telling you everything you need to know our magnetic poles and the real ramifications when they flip.

Turns out to be not such a big deal after all.

 

https://news.nationalgeographic.com/2018/01/earth-magnetic-field-flip-north-south-poles-science/

[Janus]

12 hours ago, T. McGrath said:

That is good news for the current generation.  At least we will be spared being further irradiated by a weakening magnetic field (assuming a Carrington Event is not in our immediate future).  Magnetic north is continuing to migrate across northern Canada towards Siberia at a rate of between 55 and 60 km per year, but nobody uses compasses any more.  Compasses are so last century technology.  With GPS who cares where magnetic north is located or where it goes?

Private pilots most likely still care.   If something were to go amiss with the GPS in flight, you might need to rely on your compass. 

[LaurieAG]

19 hours ago, Janus said:

Private pilots most likely still care.   If something were to go amiss with the GPS in flight, you might need to rely on your compass. 

You said it Janus and others who note UTC time (based on GPS) discrepancies know how unreliable it has been recently,

I noticed that one of our Bureau of Meteorology radars, a relatively new high tech dual polarisation radar, had its UTC timer out by 4 hours from April 2 to April 6 between at least 6:00 am and 11:00 am AEST this year. I stayed up the next morning on April 7 and noticed that the radars UTC time was correct at 3:00 am AEST, was out by 30 mins by 3:30 am AEST and was correct again at 3:35 am AEST. I also noticed further weird UTC discrepancies in the mornings from March 25 while following the Tiangong 1 reentry on satview.org and they receive data from radars all around the world. 

The current GPS Block IIF Satellites have reprogrammable processors that can receive software update uploads so that's about the only way GPS could possibly be out by exactly 4 hours for a fixed time period over many consecutive days for many different radars around the world. https://en.wikipedia.org/wiki/GPS_Block_IIF#New_characteristics

That's probably why Europe, Russia, China and even Elon Musk either have or are currently setting up their own GPS type systems.

Edited May 11, 2018 by LaurieAG
add link

[swansont]

1 hour ago, LaurieAG said:

You said it Janus and others who note UTC time (based on GPS) discrepancies know how unreliable it has been recently,

The wording seems a little ambiguous here, but if you meant to imply that UTC is based on GPS, that's sort of backwards. GPS time is based on UTC(USNO), which is the Naval Observatory's realization of UTC, and the latter is a (large) contribution to UTC as realized by the BIPM, which sets UTC based on contributions by many labs/organizations from many countries. All contributing countries steer their clocks to UTC. GPS is often used as a method of transferring the timing information (but is done in such a way that the GPS clock ends up being subtracted out of the equation)

1 hour ago, LaurieAG said:

I noticed that one of our Bureau of Meteorology radars, a relatively new high tech dual polarisation radar, had its UTC timer out by 4 hours from April 2 to April 6 between at least 6:00 am and 11:00 am AEST this year. I stayed up the next morning on April 7 and noticed that the radars UTC time was correct at 3:00 am AEST, was out by 30 mins by 3:30 am AEST and was correct again at 3:35 am AEST. I also noticed further weird UTC discrepancies in the mornings from March 25 while following the Tiangong 1 reentry on satview.org and they receive data from radars all around the world. 

The current GPS Block IIF Satellites have reprogrammable processors that can receive software update uploads so that's about the only way GPS could possibly be out by exactly 4 hours for a fixed time period over many consecutive days for many different radars around the world. https://en.wikipedia.org/wiki/GPS_Block_IIF#New_characteristics

That's a problem with dissemination or reception, not UTC itself.

1 hour ago, LaurieAG said:

That's probably why Europe, Russia, China and even Elon Musk either have or are currently setting up their own GPS type systems.

Also that GPS is military hardware, and belongs to the US. Both of those facts are part of these decisions.

[Janus]

2 hours ago, LaurieAG said:

You said it Janus and others who note UTC time (based on GPS) discrepancies know how unreliable it has been recently,

I was referring to failure of the GPS unit in the plane itself, not a failure of the whole GPS system.  There is also the fact that not all private pilots have GPS systems installed in their planes.

[Raider5678]

2 hours ago, swansont said:

Also that GPS is military hardware, and belongs to the US. Both of those facts are part of these decisions.

2

Also, that GPS system is from the 1970s-1990s.

We have a few upgrades we could make to it. Just a few.

[StringJunky]

5 minutes ago, Janus said:

I was referring to failure of the GPS unit in the plane itself, not a failure of the whole GPS system.  There is also the fact that not all private pilots have GPS systems installed in their planes.

"There's the  church , now fly to that yellow thing over there"

"Ok Buddy"

Edited May 11, 2018 by StringJunky

[swansont]

15 minutes ago, Raider5678 said:

Also, that GPS system is from the 1970s-1990s.

We have a few upgrades we could make to it. Just a few.

GPS became operational in 1993. There were precursors, but they were not GPS. And we have made upgrades to it, and are planning more.

[NimrodTheGoat]

No worries about GPS failure, we will revert to using giant arrows on the ground for means of direction. 

https://savingplaces.org/stories/the-true-story-behind-those-giant-concrete-arrows/#.WvXgaWinHrc

Edited May 11, 2018 by NimrodTheGoat

[LaurieAG]

20 hours ago, Raider5678 said:

Also, that GPS system is from the 1970s-1990s.

We have a few upgrades we could make to it. Just a few.

If you looked at the link I posted, on GPS Block IIF satellites,  you'll see that the latest satellites, GPS Block IIIA, are due to start being launched around now. 

 https://en.wikipedia.org/wiki/GPS_Block_IIIA

The first GPS Block I satellite was launched in 1978 and was called NAVSTAR GPS and was used for concept verification while the first GPS Block II satellite was launched in October 1989 and the last in October 1990. During the first gulf war (1990/91) GPS had this thing called Selective Availability which was retired in 2000. https://www.gps.gov/systems/gps/modernization/sa/ 

https://en.wikipedia.org/wiki/Global_Positioning_System

Quote

The Gulf War from 1990 to 1991 was the first conflict in which the military widely used GPS.^[47]

https://en.wikipedia.org/wiki/GPS_satellite_blocks

Quote

A GPS satellite is a satellite used by the NAVSTAR Global Positioning System (GPS). The first satellite in the system, Navstar 1, was launched February 22, 1978.^[1] 

 

 

Edited May 12, 2018 by LaurieAG
typo