Monday , June 14 2021

A strange change of the magnetic field of our planet is messing with navigation



To properly navigate the face of our planet, we need to use the orientation of its magnetic field. And for that, we need to keep an accurate record of what this field is doing.

With this in mind, every five years scientists update a standardized model of the detailed oscillations and twists of Earth's magnetic field. But recently, things have gone weird.

The current version of the World Magnetic Model (WMM) was released by the US National Geophysical Data Center on December 15, 2014. You do not think we need to worry about an update until December this year.

Not so. A news resource about Nature by Alexandra Witze, highlights the urgent need for an expedited version of this extremely important geophysical model of the Earth's magnetic sphere.

In September, NOAA released a quick pre-release version of WMM to keep everyone in action until this new release – called WMM2015v2 – is released, but missing calculator, maps, and technical notes that accompany the full updates.

A comprehensive and tight version of WMM was expected for this week, but thanks to the closure of the US federal government, we will need to wait until the end of the month to see it.

It's not too early – the current fix is ​​outdated.

The WMM is a global map of deviations in the magnetic field lines that we hope to point the way to the poles. The following is an example of 2010.

world magnetic model 2010(NOAA National Geophysical Data Center)

For your normal weekend camper, a general feeling that the magnetic field around our planet is perpendicular to the equator is all you really need to get the most out of your reliable compass.

But not everyone can be happy with an estimate estimate. Our high school textbooks can show the magnetic field as a series of pure vertical lines, but the chaotic swirls of molten rock beneath our feet make this bubble of magnetism anything but neat.

If you're in the transportation business, or run operations for, say, the government defense department, these swings – or magnetic declines – in the field can make a vital difference when you're trying to go from A to B.

This is where WMM comes in. The model provides an estimate of how the ever-changing magnetic field will be in the near future. Normally, the margins of error of their predictions only become problematic after about five years.

During an annual model check in early 2018, researchers from the National Oceanic and Atmospheric Administration (NOAA) and the British Geological Survey had problems.

Things were so out of tune, that room for maneuver was already at the limit, and they still had almost two years to upgrade.

Geomagnetists have been closely observing the field in recent years, so they know something is wrong.

Soon after the launch of the current model, researchers reported that an intense region of magnetism accelerates in the northern part of South America, a movement that planners did not see coming.

Meanwhile, a vast extension of the magnetic field stretching from Chile to Zimbabwe has become so weak that it risks leaving dangerous levels of radiation to escape and damage the delicate electronics of passing satellites.

Then there is the meander of the magnetic poles in what is referred to as excursions. The magnetic north pole is taking a break for Siberia, having recently crossed the international date line.

There is a debate about whether such events foreshadow a complete reversal or a long-term weakening of the whole field.

In short, no one is really so sure as to what is happening or how to predict these deviations. And some of these changes have a greater impact than others.

"The fact that the pole is accelerating makes this region more prone to big mistakes," said geomagnetist Arnaud Chulliat of the University of Colorado at Witze.

Researchers are feeding on several years of data to provide a short-term fix to take us through 2019, with the usual update still planned for the end of the year.

Whether these types of fixes will become a regular event, or if the five-year lifespan of each version of the model needs to be rethought, time will tell.

Geologists are working hard to find out what kinds of underground weather events are causing these signs and what that means for the future.

One thing is for sure – we are woefully unprepared if the field does something very crazy.

With your fingers crossed, we'll see the model adjusted online before February arrives.


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