Biggest solar explosion in 6 years causes radio blackout – 12/16/2023 – Science

NASA’s Solar Dynamics Observatory, the United States space agency, reported that last Thursday afternoon (14) the largest solar eruption since 2017 occurred, which caused telecommunications failures in parts of South, Central and American America. of the North, due to the enormous amount of radiation emitted.

According to the observatory, the explosion was category X2.8. Solar flares are classified according to their intensity and range from class B (weakest) to C, M and X (strongest). Each change in letter rank represents a tenfold energy increase. And within each letter the scale is subdivided into numbers from 1 to 9, with 1 being the weakest in the class and 9 being the strongest.

The last major eruption occurred in September 2017: an X8.2.

During these explosions, or solar flares, energetic particles are emitted and travel at speeds very close to that of light. Therefore, they reach Earth in around eight minutes, increasing the level of radiation. They are detected by Goes, the NASA satellite used to study the Sun and space weather.

In addition to energetic particles, solar eruptions release coronal mass ejections (CME), which are plasma clouds that travel longer in space and take around 2 to 3 days to reach Earth. Therefore, the expectation is that this CME could arrive on Earth this Sunday (17), causing a geomagnetic storm.

“CMEs are plasma clouds that have an intense magnetic field and are usually dozens of times larger than the Earth. When they interact with the Earth’s magnetic field, they cause geomagnetic storms”, explains Marcel Nogueira de Oliveira, professor at the Institute of Physics from UFF (Fluminense Federal University).

Oliveira highlights that these events, although rare, are usually part of the 11-year solar cycle, mainly at the peak of the star’s activity, known as solar maximum, which should occur in 2024. “The difficulty in predicting them is precisely which makes the study of solar physics and space weather so important and essential today.”

Scientists at the Space Weather Prediction Center of the United States Oceanic and Atmospheric Agency (NOAA) are still analyzing whether the CMEs from Thursday’s solar flare (14) were directed towards Earth. If they are, the effects will only be known when they reach our planet.

The regions most susceptible to the effects of these solar storms are the poles, where the Earth’s magnetic field is smaller. The most visible form of these phenomena is the aurora borealis, colorful and bright clouds that appear when the magnetic field receives the storm. However, experts say there is no need to worry, because the storm generated is expected to be at level G1 or G2, the lowest on the NOAA scale that goes up to G5.

“I believe it is possible that an X2 solar flare, under certain conditions, can produce a CME that in turn is capable of triggering a G5 geomagnetic storm on the NOAA scale. But the levels of problems that a G5 storm can cause is very particular and depends of several factors”, says Oliveira, emphasizing two important points:

1) larger solar flares, like an X9, are events that release more energy and, consequently, have a greater chance of producing a larger and faster CME. Therefore, larger magnitude solar flares, such as an X9 flare, are more likely to cause malfunctions and outages in our electrical systems and satellite communications systems than an X2.8 type event.

2) G5 level geomagnetic storms tend to be very rare, so much so that they have not yet occurred in the current solar cycle 25 and also did not occur in the last solar cycle, cycle 24. The last storm of this type was observed in solar cycle 23, when there were around 13 storms of this size.

When the geomagnetic storm is strong enough, it can cause major disruptions to radio communications, power grids, satellites or spacecraft. In the largest on record, in 1859, electricity surges paralyzed the world’s telegraph systems, interrupting messages.

“The more we know about the Sun and how the structures of CMEs propagate through the interplanetary medium, the more we will be able to predict the occurrence of an extreme event of this type with a good margin in advance and we will be able to mitigate its impacts. Better understand our mother star is essential for our modern lifestyle, which is highly dependent on satellites and means of communication”, concludes the physicist.

---

Check out the impacts of geomagnetic storms on Earth:

G1 (MINOR) – FREQUENCY OF 1,700 CASES PER 11-YEAR CYCLE OF THE SUN

• power systems: Weak fluctuations in the power grid may occur.
• Space operations: Possible minor impact on satellite operations.
• Other systems: Migratory animals are affected at these levels and above; Aurora is commonly visible at high latitudes (close to the north pole).

G2 (MODERATE) – FREQUENCY OF 600 PER CYCLE

• power systems: Power systems in high latitudes can experience voltage alarms and long-lasting storms can cause damage to transformers.
• Spacecraft operations: corrective actions in guidance may be necessary by ground control; possible changes in drag resistance affect orbit predictions.
• Other systems: High-frequency radio propagation can weaken at higher latitudes, and auroras have been seen as low as New York and Idaho (typically at 55° geomagnetic latitude).

G3 (STRONG) – FREQUENCY OF 200 PER CYCLE

• power systems: Voltage corrections may be necessary, false alarms may be triggered in some protection devices.
• Space operations: surface charge may occur on satellite components; drag may increase on low Earth orbit satellites and corrections may be needed for orientation problems.
• Other systems: Intermittent satellite navigation and low frequency radio navigation problems may occur; high-frequency radio can be intermittent, and auroras have been seen as low as Illinois and Oregon (typically 50° geomagnetic latitude).

G4 (SEVERE) – FREQUENCY OF 100 PER CYCLE

• power systems: Possible widespread voltage control problems and some protection systems may erroneously disconnect the network.
• Spacecraft operations: Charging and tracking issues may occur on the surface, corrections may be needed for orientation issues.
• Other systems: induced currents in pipelines affect preventive measures; sporadic high-frequency radio propagation, satellite navigation degraded for hours, low-frequency radio navigation disrupted, and auroras were seen as far south as Alabama and northern California (typically at 45° geomagnetic latitude).

G5 (EXTREME) – FREQUENCY OF 4 PER CYCLE

• Power Systems: Widespread voltage control problems and protection system problems may occur, some grid systems may experience complete breakdown or blackouts. Transformers may be damaged.
• Spacecraft Operations: Extensive surface loading, problems with orientation, ascent/descent communication, and satellite tracking may occur.
• Other systems: currents in ducts can reach hundreds of amps, high-frequency radio propagation may be impossible in many areas for one to two days, satellite navigation may be degraded for days, low-frequency radio navigation may be out of range. air for hours, and auroras have been seen as far south as Florida and southern Texas (typically 40° geomagnetic latitude).

_{Source: United States Oceanic and Atmospheric Agency (NOAA)}