In the last few days, they have been created unjustified alarmism on the possible arrival of a geomagnetic storm and an international radio blackout for tomorrow Friday July 26, 2024 (but in reality, as we will see, no geomagnetic storm is forecast for Friday) according to observations from NASA’s Solar Dynamic Observatory. Many media outlets and newspapers have chosen headlines that have created concerns among the populationsuch as “Worldwide blackout coming”, “NASA raises the alarm”, “Danger of serious damage”, “The most intense solar storm in the last 165 years” (I will return to this point later because it is truly hilarious). There are even those who have predicted the return of the Northern Lights in Italy. In reality the situation is very different and to understand this, just read the data from the reference body for space weather, the Space Weather Prediction Center of NOAA.
NOAA forecasts radio blackouts and geomagnetic storms
The Space Weather Prediction Center does not currently predict no geomagnetic storm for tomorrowwhile for Saturday 27 July there is the possibility of a “minor” geomagnetic storm of G1 categorythe weakest class, which would likely have minimal effects on electrical networks and communications. Among other things, the site spaceweather.com, another international reference for space weather, speaks of «low probability forecast», that is, “low probability forecast”. We may therefore not even see any geomagnetic storm.
As for the possibility of a radio blackout, the NOAA Space Weather Prediction Center currently evaluates a probability of 30% that nothing happensto the 60% chance of minor blackouts or moderate (so on scale local) And “only” 10% the likelihood of widespread blackouts.
If we go to look at the forecasts on the official website of the Space Weather Prediction Center we find everything already on the home page. The acronyms R1-R2 indicate respectively the possibility of minor blackouts (category R1) or moderate (R2), while R3-R5 the possibility of intense blackouts (categories R3, R4 or R5). So yes, technically the risk of large-scale blackouts cannot be ruled outbut the probability of a global blackout (which in any case would be limited “only” to the face of the Earth exposed to the Sun), therefore of category R5, is significantly lower than 10%not enough to justify the catastrophic headlines we are reading these days.
Radio Blackouts and Geomagnetic Storms Should Not Be Confused: The Differences
It is also important to underline that in this case It’s wrong to lump geomagnetic storms and radio blackouts togetherbecause we are talking about different physical phenomena that have different origins (which is why NOAA classifies their risk separately and on different scales). Geomagnetic storms are caused by plasma expulsions from the Sun, that is, electrically charged particles of matter (mainly protons and electrons). Radio blackouts, on the other hand, are caused by solar flares, that is, intense localized emissions of high-energy electromagnetic radiation (X-rays and far ultraviolet rays).
These radiations have enough energy to ionize the neutral atoms present in the ionospherethe layer of the Earth’s atmosphere above about 60 km altitude in which ions are also present. The ionosphere is essential for radio communications because reflects radio waves thus allowing the signals emitted on Earth not to disperse in space and to be detected even at great distances. When there is a sufficiently intense solar flare, the X-rays and UV rays arriving from the Sun strip electrons from atoms, thus increasing the number of free electrons in the lower ionosphere, temporarily altering its balance and therefore its effectiveness in interacting with radio signals. Having to interact with more electrons, radio waves are degraded or weakened until they are completely absorbed, thus preventing radio communications and causing blackouts.
Geomagnetic storms can also interfere with radio communications, for similar reasons, with the difference that in this case it is the energy of the particles expelled by the Sun that ionizes the lower ionosphere. This mechanism is however decidedly rarer and less effectivewhich is why the most tangible effects of a geomagnetic storm concern electrical grids and the operation of satellites.
The origin of the alarmism of these days
But where do all those worrying headlines that we read on the Internet and social media come from? To understand this, let’s go back to the beginning of this story, based on factsOn Tuesday, July 23, the Space Weather Prediction Center issued a warning for a possible geomagnetic storm of Category G2 (“moderate”, that is, of relatively low intensity) for the following day. However, this storm never occurred, because the expulsion of solar matter was unable to “hook” onto the Earth’s magnetic field. NOAA updates then began to speak of possible radio blackouts (which, however, we recall, in this case they are not related (to possible geomagnetic storms) and the media began to mix the two, with headlines like “Solar storm to cause blackouts.” Only today did NOAA release a forecast for a possible G1 storm on Saturday, so any content that talked about a solar storm coming on Friday simply he said something that wasn’t truenot counting the low probability of a widespread blackout which we talked about above. It is one thing to communicate a forecast, it is quite another to worry the population.
In short, what happened was likely the result of amisunderstanding of what was happening united to a failure to verify the primary sourcewhich in this case is the site of the Space Weather Prediction Center where the key information is reported in a particularly clear and understandable way even for non-experts.
All this is even more surreal the moment the information began to circulate in the media that The most violent solar storm in the last 165 years is coming. Why exactly 165 years? Because 165 years ago, that is, in 1859dates back to the Carrington event, the most intense geomagnetic storm ever recorded. But it is absurd to even think that a “moderate” category G2 storm could be the worst since the Carrington event: for example, in May of this year alone there was an “extreme” category G5 storm, which had significant effects all over the world. Not to mention the “Halloween solar storms” of 2003, also category G5.
With a little research you will find that this information comes from the Daily Maila newspaper that is notoriously not particularly authoritative. But the funniest thing is that the Daily Mail brought up this number in an article in May, in the aftermath of the G5 storm, in which he said that scientists had predicted even more intense storms for 2025, the worst since the Carrington event. The fact that this number has ended up in articles in recent days regarding the latest NOAA forecasts is therefore laughably grotesque.
In conclusion, when talking about these topics you should be much more careful researching sources, verifying sources, and properly communicating risk. Space weather is not a game for nerds or a scientific curiosity, but a crucial tool to protect us from the enormous damage that an extreme geomagnetic storm can cause. If you shout “Cry wolf, cry wolf” unnecessarily and too often, the response may not be adequate if or when there is a real need to intervene promptly.
