"Earth’s magnetic field is acting up"

[AKar]

Interesting article by Nature.

According to the article, the rate at which the Earth's magnetic field is changing has recently been higher than in near history - and much higher than expected by the magnetic field's mathematical model that is now pending an update ahead of schedule to account for this. This includes not only the traveling of the magnetic poles but other changes as well which do affect the strength and direction of the local magnetic field at a given point on Earth.

For us flight simmers, this means that the Earth's magnetic field has changed since the epox 2009, from where the FSX/P3D magnetic model dates, so much that it may very well be noticeable. The free update to magnetic variation by Hervé Sors has recently been updated to new epoch January 1st, 2019.

Because aviation is referring to magnetic directions, procedures, runway numbers, and VOR stations - all of which are obviously inherently true-pointing - require occasional adjustments so that the difference due to changing magnetic variation remains small enough to not make a meaningful difference. Also, larger airplanes that navigate using inertial and GNSS fed flight management systems live in true-referring system and the magnetic heading as displayed to the pilot is fetched from a lookup table - one more thing that needs a periodic update! The same, of course, applies to GPS gadgets in modern day GA airplanes.

-Esa

[Hook]

so much that it may very well be noticeable

It was already noticeable if you used skyvector.com to plan flights and weren't using VORs. Magnetic headings were often off. I got an update for the variation and it helps, but VORs are still off by a few degrees. They were already off before the update though.

I could be flippant and ask if this is related to global warming.

Hook

[AKar]

Whether the changes over ten years (2009 to 2019) are noticeable or not depend rather directly of where one is flying in the simulator. Some areas have had fairly little changes and using the outdated default magvar file modeled after the 2009 epoch most likely won't cause differences that are navigationally significant. On the other hand, in some other areas the change has been worth of several degrees and easily making difference.

Anyways, the point is that it turns out the last ten years since the FSX/P3D default magnetic variation data was compiled have seen extraordinarily fast changes in Earth's magnetic field - and the next ten years seem to have some as well.

VORs may be few degrees off in real life. That's why plotting a magnetic course from a station does not, in general case, necessarily result in one flying the exact same radial that the magnetic heading would imply.

-Esa

[Hook]

I discovered early on that if you plotted a course in airnav or skyvecor from a VOR you would get the proper VOR radial, but if you moved the point a bit along the same line you would get a magnetic heading which could be different.

Are they using the word epox now instead of epoch? A google search does not turn up anything useful for epox.

Hook

[AKar]

No, 'epoch' is proper English, not sure where 'epox' stuck from.

-Esa

[Buffy Foster]

I guess we'll need updated compass correction cards, too.

[ilya1502]

I guess we'll need updated compass correction cards, too.

No, why? A compass correction card has to deal with how a compass is affected by the aircraft structure and equipment, not by the Earth magnetic field.

[Buffy Foster]

Oh yeah sorry I got confused. :\

No posting before coffee.

[Killratio]

I could be flippant and ask if this is related to global warming.

Hook

Of course not!!! It is related to all those fly spray cans I used in the 70's

[aonyn]

I could be flippant and ask if this is related to global warming.

Hook

Of course not!!! It is related to all those fly spray cans I used in the 70's

Nah! Too many flatulent cows, not enough Beano.

[Paughco]

Didn't I just see something about that on SecureTeam10? https://www.youtube.com/user/secureteam10

Seeya
ATB

[AerialShorts]

The variation in the earth's magnetic field is really interesting and signals we are heading into a pole flip where magnetic north becomes south and vice versa. They happen every few hundred thousand years but we won’t get to see it (geologic time scales) but the earth is due. The magnetic field will get weaker and more chaotic into the flip and auroras will be visible all over the globe because we won’t have the stable magnetic field to funnel solar winds into the poles. Lots more cosmic rays too as the solar wind smashes directly into the planet broadside. And some of the atmosphere gets ripped away as well.

Nothing at all to do with global climate change which is happening way faster than geologic time scales.