Sergey Bogachev: Intense Solar Flares and Magnetic Storms Ahead

What does your laboratory do?

Sergey Bogachev: The laboratory`s focus is inherently linked to the Space Research Institute`s mission. Space is boundless, yet it can be categorized: galaxies, stars, the Moon, planets. We specialize in the Sun. Solar science is largely seen as an applied field today. Modern scientists are keenly interested in how the Sun affects Earth, so solar physics is shifting towards studying solar-terrestrial connections.

People often ask us, “Where`s your telescope?” But we don`t have one; we work with data obtained from space. The laboratory also possesses production capabilities, building instruments, developing electronics, and conducting equipment testing.

On your website, you primarily publish information about solar flares and their consequences on Earth. How much of the laboratory`s work does this activity constitute?

Sergey Bogachev: This activity is in high demand, but surprisingly, it’s secondary and tangential. Our main focus is fundamental science, which might not be visible to everyone, much like the submerged part of an iceberg. For instance, we are currently actively studying small solar flares. This can be compared to the well-known fact that the total mass of all bacteria on Earth is much greater than, say, the mass of all elephants. There`s a hypothesis that even on the Sun, the largest flares, the massive explosions we observe, constitute only a small fraction of the true energy, and we simply lack the instrument sensitivity to observe the hidden portion.

Overall, this is supported by indirect evidence. For example, the Sun has a hot corona with a temperature of millions of degrees. If large flares were its sole heat source, the corona`s temperature should decrease when flares subside. But this doesn`t happen. This suggests something else, “invisible to the eye,” is heating it. And, of course, we want to try to see these hidden processes. Therefore, we are currently working actively, including trying to prove the necessity of launching high-precision telescopes into space that can observe such processes. And, naturally, we conduct theoretical research. We are currently, perhaps, one of, or even the leading group in the world addressing these questions.

The peak of solar activity for this cycle appears to have passed. Is this truly the case, or are there nuances?

Sergey Bogachev: At this moment, we consider a return to last year`s peaks impossible. The observed degree of decline in solar activity already exceeds all possible fluctuations and random deviations. For example, in the first half of last year, there were over 30 X-class flares, whereas this year, over the same period, there were only 10. Last year, the strongest flare was X8.7, this year it was X2, meaning it was four times weaker.

There are other signs as well. The Sun currently has many coronal holes, which appear during activity minima. The number of sunspots has significantly decreased. For someone involved in solar physics, these are as obvious signs as, for example, leaves yellowing or daylight hours shortening as autumn approaches.

Some try to point out that solar cycles often have two maxima, suggesting we might have passed one and are now heading for a second. While true that two maxima can occur, there aren`t such deep dips between them. Furthermore, two maxima don`t happen every time, only in about half of the cycles. We believe that this cycle had one maximum, and it has passed; we are now in a slow but steady phase of decline.

How did the past maximum compare to those observed previously?

Sergey Bogachev: The strongest cycle ever observed was the 19th, with its maximum in 1958. It is believed to have coincided with a “secular maximum.” The current cycle, it was thought several years ago, should have fallen within a “secular minimum.” All forecasts predicted a very low cycle, but they were not justified; the recorded activity was approximately twice as high as predicted.

The past cycle significantly, by about 50%, surpasses the previous one. However, it`s still not a record; it falls short of the mid-20th-century maxima by the same 50 percent. So, we can say the cycle was unexpectedly strong, but if someone thinks they lived through something historically unprecedented and survived, wiping sweat from their brow, then no, there was nothing historically exceptional about this cycle.

Moreover, speaking of the 21st century, the most active period was from 2001 to 2003. During this time, there were very strong magnetic storms and, more importantly, exceptionally strong flares up to X40. In the past cycle, there wasn`t a single flare even at the X10 level. We haven`t experienced anything record-breaking, but perhaps nature will “make up for it” in the next cycle.

Can long-term forecasts be made based on data from past cycles?

Sergey Bogachev: On one hand, predicting the solar cycle seems simple because it`s an 11-year cycle. It seems like, what`s there to predict? The maximum was in 2014, add 11 years, that`s 2025, add another 11 years, it will be 2036. And so on, you could forecast a million years ahead. But that`s not quite right because, firstly, there are fluctuations; the next peak could be in 10, nine, or 12 years. But that`s not the main point. Radio amateurs will understand: in radio transmission, there`s a carrier frequency and modulating envelopes on which the signal is encrypted. The 11-year carrier frequency works more or less stably. But the modulation, which determines the height of the cycle, changes quite significantly. Over 25 observed cycles, it`s clear that such envelopes exist. There are even some indications as if this envelope follows a century-long pattern.

However, we don`t know its nature or the laws by which it develops. Besides the centennial envelope, there might be a millennial, or even a million-year one. But overall, we understand that such a process is at work, and if centennial, regular, millennial, and hundred-thousand-year minima all align at some point, a global slump in activity is possible. For example, a new Maunder Minimum (the period from 1645 to 1715, when there were very few sunspots) or an ice age. Conversely, if all maxima align, new Carrington events (the powerful flare and geomagnetic storm of 1859 and its consequences) or Miyake events (periods when a significant increase in radioactive carbon isotopes in the atmosphere was recorded in 773 and 993 AD) could occur.

Apparently, we passed the lowest point of the secular cycle in the previous cycle, and now we are growing upwards, and all subsequent cycles will be stronger. Therefore, if you ask for my forecast for the next 20-30 years, I believe we will see significant growth, and each cycle will become more and more powerful. But again, nature is famous for its unpredictability; it`s possible everything will be the opposite.

Will solar activity reach the levels of 2001-2003 or even the records of the mid-last century?

Sergey Bogachev: It might even be stronger, because we don`t know what global envelopes are superimposed on this process. Perhaps the secular maxima, which have their own envelope, are also currently increasing. It is quite possible that the secular maximum in the mid-21st century will be higher than the secular maximum of the last century. But here we enter territory where we lack data. And the problem is that solar flares leave no traces. A meteorite, for example, fell a million years ago, we find craters, and we know everything about it. But a solar flare that occurred a million years ago will leave absolutely nothing on Earth. Even all the radioactivity it produces will completely dissipate. So we have no information about solar activity older than 10,000 years. Therefore, unfortunately, we predict everything with considerable uncertainty.

Where do scientists get data on solar activity older than 10,000 years?

Sergey Bogachev: Primarily from radioactive carbon-14 (C-14). This is a known element produced from nitrogen, and its production is stimulated by solar activity. Carbon is the basis of everything around us, all life. It is easily absorbed by plants or accumulates in Antarctic ice. Miyake events were discovered through tree rings. On a cross-section, you can see that in a certain year, there was a peak of incredible power. This is how we know that the Sun can have flares hundreds or thousands of times stronger than Carrington events. The Carrington flare, whose exact date is known to us, left no trace in tree rings. But the event in 773 AD left such radioactivity that we still see its trace more than a thousand years later.

Is there a chance to get closer to understanding these modulating envelopes?

Sergey Bogachev: Progress in any science is only possible after building a proper physical model. While you`re gathering data by touch, you`ll certainly learn something, but it`s the knowledge of a blind person exploring an object. Once you understand the physics of the process, of course, the picture becomes much clearer. It`s now understood that the Sun`s physics involves a mechanism called the dynamo mechanism. But the parameters that govern it are unclear. Perhaps planets with their gravity are swaying the Sun, or maybe there are some internal oscillations of the Sun`s core. We can only guess; there isn`t a single reasonable hypothesis.

The next peak will be in 9-10 years. Will the Sun be calm all this time?

Sergey Bogachev: It`s quite accurate to draw an analogy with normal climate. For example, we all know that from winter to summer, the temperature gradually rises. But this doesn`t negate the possibility of snow in May. Or amidst a general drop in temperature in autumn, there might suddenly be heat in September.

Roughly the same applies to the solar cycle. The cycle will slowly decline for about four years. During this period, unexpected, very strong events, powerful flares, and storms are possible. In the previous two cycles, record events occurred not at the peak, but 2-3 years after it. The strongest flare of the 21st century, X40, happened in 2003, whereas the maximum was in 2001. And the strongest flare of the next cycle was in 2017, three years after the peak.

Truly “dead” periods are usually only two or three years. In the previous cycle, these were 2018-2020; in this one, they will be approximately 2029-2030, perhaps partly 2031.

Can we learn to predict ice ages if we understand how this mechanism works?

Sergey Bogachev: This is quite a speculative topic. It`s important to understand that the Sun, as a source of heat and light, shines quite stably; it shone the same way a million or even a hundred million years ago as it does now. That is, the Sun`s global luminosity does not affect Earth`s climate. Greenhouse gases are considered the main factor regulating Earth`s temperature. They allow light to reach Earth but prevent Earth`s heat from escaping, thereby raising its temperature.

In our modern era, Earth`s average temperature should be approximately -15 degrees Celsius, but it`s +15, meaning it`s about 30 degrees higher than what the Sun alone provides. And this increase is precisely due to greenhouse gases. Greenhouse gases, mainly triatomic molecules like water vapor, CO2 (carbon dioxide), and O3 (ozone), are at high altitudes where solar radiation is quite active, and therefore they are very sensitive to solar activity.

Since changes in solar activity can influence greenhouse gases, the hypothesis that flares can regulate Earth`s climate is plausible and widely accepted. It`s difficult to confirm because, thankfully, we haven`t personally experienced an ice age. However, there were so-called “Little Ice Ages” – climatic depressions in the Middle Ages. These are confirmed by contemporary accounts describing snow in June and crop failures. And at least one such depression, which occurred when the Sun was already actively being studied, coincides with a period of low solar activity. So, by understanding solar activity, it might be possible to predict ice ages, but unfortunately, we don`t understand it yet. That`s precisely what we`re working on.

A more speculative question: Many people believe that flares and magnetic storms affect well-being, mostly negatively. What`s your view on this?

Sergey Bogachev: The polarization of opinions on this issue is truly striking, sometimes leading to aggressive disputes among people. As a scientist, I dislike extreme viewpoints and would like to correct both. To people who claim it`s all nonsense, saying “you`re not afraid to ride a tram, but you`re afraid of storms,” we usually advise them to consult the Sanitary Regulations (SanPiN) standards. This state document explicitly states that variable magnetic fields are harmful to humans. Moreover, it includes protection norms. Of course, these are not for magnetic storms, but for variable magnetic fields.

Then there`s the other extreme: people who try to explain any ailment with external factors. This isn`t entirely correct either, especially if it leads to self-medication. Physics reveals mechanisms by which magnetic storms influence humans. Variable magnetic fields generate eddy electric currents, not just in technology but also in the human body. At the technical level, this influence has been experimentally recorded, reliably confirmed, and can be measured. You can`t connect an ammeter to a human, so confirming this influence on people is much harder. Cardiologists professionally study this topic. In my opinion, this is appropriate, because if I, as a physicist, were to look at a human, of course, the eddy currents would primarily affect the circulatory system. There are many ions and blood plasma there. But, of course, I am not ready to give specific recommendations, or precisely at what storm level one should hide, and at what level one can live peacefully.

How have the means of observing the Sun changed from the beginning of the space age to today?

Sergey Bogachev: The main thing that came with the space era was the space era itself – the ability to put instruments into space. Earth`s atmosphere, fortunately for all of us, protects quite well from harmful radiation, and hard wavelengths and particles. But for astronomy, it protects too well; if you observe from Earth, you simply can`t see anything. To see solar flares in all their diversity, including their harmful aspects, instruments must operate in space.

Of course, progress in electronics is very important. Everyone who uses mobile phones sees how the number of megapixels in cameras increases. In a sense, a space telescope is a large camera. And, to a significant extent, those amazing images and the precision with which solar images can now be obtained are ensured by progress in electronics, detectors, and information processing and storage. The optics themselves, which make up a telescope – the tube, mirrors, lenses – surprisingly, have hardly changed in the last 100 years. Even more so, there are many observatories on Earth with telescopes whose optics were created in the last century. They simply updated the detectors, and they work perfectly for astronomical tasks.

And, of course, progress in computers. For example, the SDO solar telescope, the most famous one currently, transmits two terabytes of solar images per day. It`s absolutely impossible to view and comprehend them visually. Of course, without computer processing tools, almost nothing could be studied.

What capabilities does Russia have in satellite solar monitoring? What data do you use?

Sergey Bogachev: The last dedicated solar observatory of the Russian Federation, `Coronas-Foton,` completed its operations on November 30, 2009. Since then, the main source has been open foreign data. I would like to commend Rosgidromet (Russian Hydrometeorological Service); they are trying to rectify this in some way by installing solar instruments on their meteorological satellites. But these are very simple, second-tier instruments. They can work in addition to larger telescopes but are not capable of independently forming a space weather forecast.

You mentioned promoting the idea of needing your own telescope. Is that what you`re referring to?

Sergey Bogachev: Yes. This issue first became acute for the community in 2009 when the domestic solar satellite `Coronas-Foton` ceased operation, and we had to consider what to offer as a replacement. Ideas were expressed that, personally, seemed correct to me at the time, about repeating this apparatus at a higher technical level. This involved a concept envisioning the installation of a large number of monitoring instruments on a single satellite.

But a second proposed concept was chosen – to do something entirely new, revolutionary. The `Interheliosond` project received support, in which a satellite was supposed to fly towards the Sun, be shielded by a heat shield, and then exit the ecliptic plane using Venus`s gravitational field! Unfortunately, in our mentality, it`s believed that for a project to succeed, it must be somewhat revolutionary, so that its idea is breathtaking. In many ways, this approach did harm here. This project progressed with considerable difficulty, and in recent years, unfortunately, it has been practically stagnant. In my opinion, it largely collapsed under its own weight. In recent speeches concerning the program of fundamental and technological space research of the Russian Academy of Sciences, the `Interheliosond` apparatus is no longer mentioned. At the same time, even if it is being closed, I believe the groundwork created within its framework (instruments, mock-ups) should be preserved and transferred to a new project so that it does not start from scratch. A dedicated solar observatory is needed for the country in any case, and the timing of its construction is of significant importance.

As an example of a different concept, we can cite the leading foreign solar observatory SDO, without whose data no scientific article on solar physics today can do without. The main instrument of SDO, called AIA, is simply four telescopes, albeit very good, high-quality ones. In our system, such a project, however sad it may be, would almost certainly not receive support: they would say it does not solve any fundamentally new tasks. Speaking about the future, I think we need a relatively simple and high-quality monitor satellite with good modern solar telescopes, photometers, particle detectors, and solar wind monitors. It should presumably be launched to the L1 point, where the gravitational influences of the Sun and Earth are balanced. The scientific community supports such a concept and such an orbit. We can build all the necessary instruments. And for those we can`t, we know where to simply buy them turnkey. As a kind of surrogate, we are now actively engaged in nanosatellites. But the instruments we can put on them are very simple, capable of providing only a minimal level of research. For full-fledged research, of course, a large satellite is needed.

What capabilities does your laboratory have in the field of instrument manufacturing?

Sergey Bogachev: Primarily, the work proceeds within the framework of state orders. Unfortunately, at present, there are no large “hardware” projects in solar physics; it`s mainly preliminary design and research work. Our country has been affected by the global trend for small CubeSats. We make instruments for them. In 2023, there was a large launch where five of our instruments flew, two of which are still working, and we are receiving data from them. We are currently making new instruments for CubeSats, but it will almost certainly not be possible to launch them before 2027.

Can private space companies order instruments from you?

Sergey Bogachev: Scientific organizations are permitted to engage in contractual activities in addition to state assignments. We also participate in this activity. There have been instances where we built something not for ourselves, but for other organizations. We have competencies in detectors and optics that not everyone possesses. Such work is conducted, but mainly for financial reasons and to support the team. Unfortunately, such external activities do not advance the science we ourselves are engaged in, which is solar physics.