Tag Archives: geomagnetic storm

Northern Lights.

Solar storm expected to bring northern lights to the U.S. tonight

There’s more bad weather forecasted for today, but this is the kind that we’ll all be thankful for — a minor solar storm will hit our planet on Wednesday, March 14. The event could amp up Earth’s auroras, making them visible from the northernmost parts of the U.S.

Northern Lights.

Image credits Svetlana Nesterova.

“Northern tier” states, such as Michigan or Maine, could be in for a treat as amped-up auroras (northern lights) could dance across the sky tonight, a product of a solar storm inbound towards Earth. The same storm could also induce some fluctuations in weaker power grids, and should only have a minor effect on our satellites, according to an alert issued from the Space Weather Prediction Center (SWPC), part of the National Oceanic and Atmospheric Administration (NOAA), in Boulder, Colorado.

Researchers at the SWPC predict that the storm originates from a coronal hole in the sun, a region of lower energy and with a weaker magnetic field in the Sun’s outer layer. The particular conditions in this area allow high-speed, charged particles to shoot out into space, eventually finding their way to Earth. The storm will be a G1 class — making it a relatively minor event — and should last from Wednesday to Thursday, March 15.

Light it up

Auroras (known as ‘borealis’ over the North Pole and ‘australis’ over the South Pole) form from the interaction of these particles with the Earth’s magnetic field. Because they are charged, they are directly affected by the magnetic field when trying to pass through; similarly to how a pane of glass would ‘interact’ with you, should you try to pass through it.

We don’t fully understand the mechanisms behind aurora formation, but, in broad lines, the pretty colors are the result of ionization in the upper atmosphere. This, in turn, is produced by successive collisions of high-speed charged particles with atoms in the Earth’s upper atmosphere, causing them to shed electrons and protons (to ionize). Auroras can form on other planets with an atmosphere, through a similar process.

Particularly strong solar storms can trigger geomagnetic storms. Depending on its intensity, this could mean radio blackouts, fluctuations in power grids, maybe even with satellites in orbit.

Auroras or polar lights typically form near the (magnetic) poles, where the geomagnetic field is thinnest, and these charged particles can force their way through. Events such as solar storms widen the area on which auroras form because they put out more charged particles than usual — the deluge compresses Earth’s magnetic field, so some particles can push through at lower latitudes. In 1989, for example, a similar event made auroras form all the way down to Texas.

So fingers crossed, and you might get to enjoy one superb light show later today — nature’s treat.

How northern lights and stranded whales might strangely be connected

Researchers found an unlikely connection between stranded whales and the Northern Lights.

The northern lights might be a brilliant spectacle for some, but they might have spelled doom for some unfortunate sperm whales. Credits: NASA.

In early 2016, the stranding of 29 sperm whales in the North Sea left researchers surprised, since these whales are not normally found in that part of the world. None of them survived. Autopsies revealed that the whales were all in pretty good health, so the exact reason why they became stranded in shallow waters remained a mystery. Now, researchers proposed an unexpected culprit: geomagnetic storms.

Sperm whales live in temperate to warm waters all year long. They tend to migrate between the warmer equatorial waters and the colder but squid-rich waters of the Norwegian sea. The North Sea isn’t really on their list, and neither is it on the list of Gonatus fabricii squid — their preferred food — so it doesn’t make much sense to venture that far. They normally stick to the western side of Great Britain, whereas the North Sea is more to the east. That fatal mistake might be explained through magnetic fields.

The magnetic map of where the Norwegian and North Seas join. The whales should have traveled along the white arrow, but instead traveled along the red arrow. Credit: Vanselow et al.

The Earth’s magnetic field is not uniform — it has numerous anomalies, both positive and negative, big and small. It’s thought that some creatures use this field to navigate through their migration, but this technique can be severely disturbed by solar storms, which produce huge differences that totally confuse the animals. This is a relatively new concept, but it has been previously documented in both birds and bees. Dolphins also seem to use the magnetic field, so it would make sense for whales to do it too.

Dr Klaus Vanselow from the University of Kiel, Germany, believes this is also what happened to the whales. He and his team claim a large solar storm distorted the magnetic field, causing the unfortunate mammals to lose their way in the sea. The same solar storm produced spectacular northern lights, visible from the Arctic down to Scotland.

Specifically, they identified two such storms occurring on December 20/21, 2015, and December 31 and January 1, 2015/2016. They found that the anomalies caused by these storms stretched down to the Shetland Islands, where the whales would have turned right (east) instead of left (west). Normally, the whales would sense a magnetic barrier in front of the North Sea and avoid diving into it, kind of like a magnetic mountain. However, the storms “leveled” these magnetic mountains, rendering them invisible for the whales.

This misstep was all it took.

“Sperm whales are very huge animals and swim in the free ocean so if they are disrupted by this effect, they can swim in the wrong direction for days and then correct it,” says Vanselow. “But in the area between Scotland and Norway, if the whales swim in the wrong direction for one or two days, then it is too late for them to go back, they are trapped.”

This seems to fit very well with the timeline of the whales but of course, correlation does not imply causation. We still don’t know exactly how the whales detect and operate based on this magnetic field, and just because this seems to fit doesn’t mean it is indeed what happened.

“It would be difficult to say that ‘yes this was the cause’, we would be cautious in saying that,” said Abbo Van Neer from the University of Hannover who carried out the autopsies on the 16 whales that stranded in Germany. “But it is a valid hypothesis and a potential reason for the stranding.”

In other words, it’s a properly designed study that offers a solid hypothesis, but it doesn’t really prove anything. Dr Antti Pulkkinen, who is leading a NASA effort to investigate the link between strandings in Cape Cod and geomagnetic storms, says there’s just not enough data to draw a definite conclusion.

“Having looked at this problem from a data analysis point of view, it is not a single factor that contributes to this. Things need to line up from multiple different perspectives for these events to take place.”

Journal Reference: Klaus Heinrich Vanselow, Sven Jacobsen, Chris Hall and Stefan Garthe. Solar storms may trigger sperm whale strandings: explanation approaches for multiple strandings in the North Sea in 2016. DOI: https://doi.org/10.1017/S147355041700026X

 

A solar flare accompanied by a coronal mass ejection (CME) erupted from the sun on January 23rd 2012. Credit: NASA/SDO

Strongest geomagnetic storm this solar cycle sparks dazzling Northern Lights

A pair of coronal mass ejections (CMEs) emitted by the sun last Sunday have now triggered a severe geomagnetic storm around the globe. At first, only a mild geomagnetic storm was registered after the first wave hit our planet’s magnetosphere. Quickly, however, the storm has intensified to G4 status, or only one notch below  the highest level solar storm, according to the NOAA’s Space Weather Prediction Center. This is the most severe solar storm of the current solar cycle.

A solar flare accompanied by a coronal mass ejection (CME) erupted from the sun on January 23rd 2012. Credit: NASA/SDO

A solar flare accompanied by a coronal mass ejection (CME) erupted from the sun on January 23rd 2012. Credit: NASA/SDO

The amount of magnetic flux that rises up to the Sun’s surface varies with time in a cycle called the solar cycle. This cycle lasts 11 years on average, and during its maximum peak  major flares and CMEs are commonplace. This peak was predicted to have occurred in 2013, but this most recent event suggests that the solar cycle #24 is not over yet.

Coronal mass ejections are powerful eruptions near the surface of the sun driven by kinks in the solar magnetic field. When the sun burps, it does so with the strength of 20 million nuclear bombs, ejecting more than a billion tonnes of superheated gas. The resulting shocks ripple through the solar system and can interrupt satellites and power grids on Earth.

We’ve yet to receive any word from NOAA whether or not this G4 storm has caused any outage or satellite malfunction, but I wouldn’t be surprised if any is reported. It’s not all doom and gloom with geomagnetic storms. In fact, we have to thank for some of the most intense and beautiful weather spectacles on Earth: the aurora. Before sunrise, bright auroras were sighted over several northern-tier U.S. states, including Minnesota, Wisconsin, Montana, the Dakotas and Washington. According to Space Weather branch chief Brent Gordon, if the storm is to continue well until Tuesday afternoon, than Northern Lights could be sighted  as far south as the middle United States, even Tennessee and Oklahoma. That also means much of Russia and northern Europe, as far south as central Germany and Poland.