The last few hours have been marked by a question that resonates both in the media and in everyday conversations: what exactly is induced atmospheric vibration, and why has it leapt to the forefront of the news? It all stems from the massive blackout that left millions of people in Spain and Portugal without power on April 28, 2025, an unprecedented event that has baffled experts and the general public alike.
The hypothesis of induced atmospheric vibration as the cause of electrical collapse has generated rivers of digital ink. However, to what extent is it plausible, what does this physical phenomenon consist of, and what does the scientific community think? Below, we'll rigorously and thoroughly unravel everything that's known—and what's still up in the air—about this concept and its possible relationship to the Iberian blackout.
The context of the blackout: the version of the electric operators
On April 28, 2025, an abrupt power outage left much of the Iberian Peninsula in darkness. The electricity operators of both countries, REN in Portugal and Red Eléctrica Española (REE) in Spain, immediately activated crisis protocols to try to clarify the causes and restore service as quickly as possible.
REN, the Portuguese public company responsible for the electricity transmission grid, pointed out in its initial communications to media outlets such as Reuters and the BBC a possible connection with a "rare atmospheric phenomenon" that occurred in Spain. According to them, intense temperature variations would have caused anomalous oscillations in very high voltage lines (400 kV), a process technically known as induced atmospheric vibration.
At the same time, the Spanish administration has refrained from making any categorical statements while awaiting the results of the investigation. The cyberattack theory was mentioned, but without corroborating evidence. Portuguese Prime Minister Luís Montenegro himself ruled out intentional attacks and reinforced the idea of a natural and highly unusual trigger.
What is atmospheric induced vibration?
The term atmospherically induced vibration describes a physical phenomenon that primarily affects high and very high voltage transmission lines. It consists of the appearance of oscillatory movements in electrical conductors (the elevated cables we see on large towers), generated by the interaction between electrical factors and external atmospheric conditions.
The process begins when certain meteorological circumstances occur, such as sustained wind, sudden changes in temperature, or high humidity. This can lead to the appearance of what is known in electrical engineering as corona discharge, which ionizes the air around the conductor and produces small currents between the metal and the atmosphere.
The charged particles thus generated interact with the intense electric field of the high voltage lines, which gives rise to periodic electrohydrodynamic (EHD) forces. These forces are not mechanical in the strict sense, but rather the result of the interaction between electricity and the atmosphere.
Due, Pressure waves are generated in the surrounding air that directly affect the cable itself.When the frequency of these alternating forces approaches or coincides with the natural vibration frequency of the conductor, the phenomenon of resonance occurs.
This resonant state can greatly amplify the oscillations of the cable., causing vibrations of considerable amplitude even though wind or temperature conditions appear to be normal to the naked eye.
How do wind and extreme temperatures affect this phenomenon?
Induced atmospheric vibration is especially likely when two elements come together: constant wind (without sudden gusts or intense turbulence) and unusual temperatures (both high and very low).
Wind can generate pressure vortices in the cable's surroundings, forcing it to move from side to side. If the speed of these vortices matches the cable's natural vibration frequency (which depends on its length, mass, and tension), intense vibrations can occur.
Extreme temperatures alter the mechanical behavior of conductors.Heat causes cables to expand and become looser, while cold causes them to contract and tighten. Both effects influence their resonant frequency, making them, in many cases, more vulnerable to wind-induced vibrations.
Added to this is the corona discharge in situations of high humidity or presence of suspended particles., which facilitates the production of the aforementioned EHD forces.
Differences with other types of vibrations in power lines
In the world of electrical engineering, high-voltage overhead lines can experience vibrations of a wide variety of types and origins. It is essential to distinguish induced atmospheric vibration from other similar phenomena that are commonly studied.
- Classical wind vibration: It produces intermediate-frequency oscillations due to the passage of wind. It is usually more predictable and especially affects longer, lower-voltage conductors.
- Gallop: A phenomenon caused by the accumulation of ice or snow on the cable, accompanied by wind. It results in high-amplitude, low-frequency vibrations.
- Induced atmospheric vibration: It is characterized by oscillating at frequencies between 0,1 and 10 Hz, and its main trigger is the combination of particular electrical conditions and atmospheric factors, not just wind.
This difference in origin and mechanism is key to understanding why induced atmospheric vibration is so difficult to predict and mitigate..
Direct and indirect consequences on the electrical system
The repercussions of induced atmospheric vibration can be very varied and depend on both the intensity and duration of the phenomenon. Although in many cases their effects are limited to audible noises or slight cable displacements, under extreme conditions they can cause real, large-scale problems.
In the long term, repeated exposure to vibrations – even of low amplitude – causes fatigue in materials. which make up the conductors, the insulators and also the hardware that keeps the entire system standing.
This translates into a higher probability of the appearance of cracks, loose connections and accelerated wear at contact points between different elements.
In some cases of especially intense atmospheric vibrations, automatic protection systems can interpret that there is a serious anomaly and proceed to disconnect entire lines to avoid further damage.
Furthermore, if the vibration alters the synchronization of interconnected electrical systems, a chain reaction of cascading disconnections or outages can be triggered, as occurred in the great blackout of April 2025, with the failure spreading beyond the initial point.
Why has the official explanation been so controversial?
The attribution of the April 2025 blackout to induced atmospheric vibration has not been without controversy. From the outset, experts in physics, meteorology, and electrical grids have expressed caution regarding the possibility of such a rare phenomenon having such a devastating effect.
Some scientists, such as physicist Mario Picazo, stressed that considerable wind or extreme thermal changes would be necessary to trigger resonances in the power grid of the magnitude observed. Although there were significant temperature amplitudes (nearly freezing nights followed by highs of 20-25°C), most consider it unlikely that this factor alone was enough to cause the collapse.
Other experts, such as José María Madiedo, an astrophysicist at the Institute of Astrophysics of Andalusia, have gone further, ruling out that induced atmospheric vibration, triggered by some rare atmospheric phenomenon, is a sufficient explanation.Madiedo proposed the possible impact of a solar event (Carrington type) as an alternative, although the lack of recent solar storms or simultaneous global impact ruled out this hypothesis.
Network operators and authorities, meanwhile, have remained cautious.Although they have acknowledged the complexity and exceptional nature of the incident, they insist that there is still no conclusive evidence regarding the exact cause. The investigation remains ongoing, and transparency has been key to avoiding hoaxes and speculation.
The recovery process and associated difficulties
Restoring power after the blackout of April 28, 2025, has been neither simple nor immediate.The main complication is that, as this is an internationally interconnected network (Spain, Portugal, France, and Morocco), any recovery attempt must be gradual and extremely coordinated.
The procedure followed has consisted of progressively activating the key generators of each country to align electricity production with users' actual consumption. This "gradual reconnection" is essential to avoid further overloads or desynchronizations that could disrupt the restoration process.
France, for example, has collaborated by supplying energy to the Spanish system through the northern border.At the same time, Portugal has proceeded to disconnect its grid from the Spanish grid to restore normality using its own resources and avoid a further domino effect.
In this stage, the study of sound in space and how vibrations can affect different systems is relevant to understanding the possible causes of the blackout.
In this stage, Resilience and coordination between operators and governments play a fundamental role to restore stability to the European energy system after an extreme event.
Lessons learned and new challenges for the future
The incident has highlighted several vulnerabilities inherent in current power grids.The pursuit of maximum efficiency through the interconnection of multiple countries and systems has complicated crisis management and recovery from serious incidents.
Furthermore, the role of extreme natural phenomena – whether temperature variations, wind or even solar effects – seems increasingly relevant in the context of climate change.Experts warn that episodes like the recent Iberian blackout could be repeated if safety protocols, infrastructure maintenance, and monitoring and early warning systems are not updated.
The investigations opened by REN and Red Eléctrica Española seek to understand whether the induced atmospheric vibration was really the "trigger" of the blackout. or simply an aggravating circumstance in a particularly delicate network context.
