Tonga’s 2022 eruption created a very rare ‘plasma superbubble’ in the ionosphere: ScienceAlert

With technology becoming more and more embedded in our daily lives, understanding space weather and its effects on technology is becoming more important.

when we hearspace climateOne usually thinks of massive eruptions on the Sun — coronal mass ejections that hurtle toward Earth, creating Beautiful twilight shows.

However, not all space weather begins at the sun.

the Volcanic eruption in Tonga In January 2022, it was so big it created waves in the upper atmosphere that formed its own form of space weather.

It was one of the largest eruptions in modern history and affected GPS across Australia and Southeast Asia. As we describe in our new study in the journal space climatethe volcanic eruption created a super “plasma bubble” over northern Australia that lasted for hours.

Truly a global positioning system

While most people have GPS (Global Positioning System) receiver on their devices (such as satellites and smartphones), not many know how GPS actually works.

In essence, our devices listen for radio signals sent by satellites orbiting the earth. Using these signals, they calculate their position relative to the satellites, allowing us to orient ourselves and find the nearby bar or coffee shop.

The radio signals that our devices receive are affected by the Earth’s atmosphere (especially the layer called the Earth’s atmosphere). ionosphere), which reduces location accuracy. Common devices are only accurate to within tens of metres.

However, newer and improved satellite positioning systems, used in the mining, agricultural and construction industries, can be accurate to within ten centimeters. The only problem is that these systems need time to install on their sites, and this can take thirty minutes or more.

this Precise satellite positioning It works by accurately modeling faults caused by the Earth’s ionosphere. But whenever a perturbation occurs in the ionosphere, it becomes complex and difficult to model.

For example, when a file Geomagnetic storm (a disturbance in the solar wind affecting Earth’s magnetic field) occurs, the ionosphere becomes turbulent, and the radio waves traveling through it get scattered – like visible light bending and scattering when looking at a lake in choppy conditions.

volcanic disturbance

recent studies It showed that the eruption of Hongga Tonga-Hong Haapei volcano caused erratic conditions in the ionosphere that lasted a few days. The waves they generated in the ionosphere were similar in size to those generated by geomagnetic storms.

While these waves affected GPS data around the world for days after the eruption, their impact on positioning was somewhat limited compared to another type of perturbation in the ionosphere – the “plasma superbubble” that formed in the aftermath of the eruption.

The ionosphere is a layer of Earth’s atmosphere at altitudes of approximately 80–800 km (50–500 mi). It consists of a gas with lots of electrically charged particles, which makes it “plasma“.

In turn, equatorial plasma bubbles are plasma disturbances in the ionosphere that occur naturally at night over low latitudes.

These plasma bubbles occur regularly. They are formed due to a phenomenon called “generalized Rayleigh-Taylor instability”. It’s similar to what happens when a heavy liquid sits on top of a less heavy liquid, and the bubbles of that lighter liquid bubble up into the heavy liquid as “bubbles” (see video below).

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When it comes to disturbances in the ionosphere, the plasma is also controlled by magnetic and electric fields.

As they rise, the plasma bubbles form oddly shaped structures resembling cacti or upside down tree roots. Because of Earth’s magnetic field, these structures spread out as the bubble grows over the equator.

The result is that higher altitude bubbles reach higher latitudes as well. Typically, plasma bubbles reach a few hundred kilometers above the equator, reaching latitudes between 15 and 20 degrees north and south.

Rare bubble over Australia

Scientists find out a Super plasma bubble Over Southeast Asia shortly after the eruption of the Tonga volcano. Its size is estimated to be similar to that previously reported Super rare bubbles.

Earth’s magnetic field carried the disturbance southward, where it lingered for a few hours over Townsville in northeastern Australia.

To date, this is the southernmost a plasma bubble has been observed over Australia. Although these superbubbles are rare, they are known to have occurred in northern Australia, but they had not been directly observed prior to this event.

The recent proliferation of GPS stations across northern Australia has made this type of monitoring possible.

It is understood that waves from the eruption disturbed winds in the upper atmosphere, altering the flow of plasma in the ionosphere and causing the plasma superbubble to appear.

Our study found that the bubble caused significant delays in the use of accurate GPS across northern Australia and Southeast Asia. In some cases, it took more than five hours to get a lock on a GPS location because of the plasma bubble.

While we understand a great deal about the ionosphere, our ability to predict its perturbations is still limited. Having more GPS stations is not only useful for improving positioning and navigation, but it also fills in gaps in ionospheric monitoring.

The eruption of the Tonga volcano was far from a typical “space weather” event caused by the sun. But its impact on the upper atmosphere and GPS highlights the importance of understanding how the environment affects the technologies we rely on.

Brett CarterAssociate Professor, RMIT University; Rize Pradiptasenior researcher in science, Boston CollegeAnd Sulin ChoiMr

This article has been republished from Conversation Under Creative Commons Licence. Read the The original article.