Heliogeophysical Conditions in Moscow during the Covid-19 Pandemic

Abstract

In this paper we consider the effect of heliogeophysical activity on the COVID-19 epidemic associated with the spread of the SARS-CoV-2 coronavirus in Moscow. An analysis of official data on the course of the pandemic has provided evidence of the effect of heliogeophysical activity on the spread of an infectious disease. The pandemic arose during the winter when solar activity was minimal and ultraviolet radiation was at its lowest. The study showed a significant relation between the infectious process and geomagnetic activity: periods of outbreaks in the number of infections and deaths correlated with periods of a decrease in geomagnetic activity lasting several months. The impact of magnetospheric storms and substorms on the human body during a pandemic is also considered. It is shown that, during the minimum of solar activity during periods of geomagnetic disturbances lasting from one to several days, both the number of infections and the number of deaths additionally and statistically significantly increase. Evidence of a direct or indirect effect of solar activity on the occurrence of outbreaks of infectious diseases is important from the viewpoint of understanding the emergence and development of epidemics.

INTRODUCTION

Infectious diseases are a serious global problem for civilization. They have occurred throughout the entire history of mankind and pose a constant threat to life on Earth. Every pandemic results in huge financial and human losses. The outbreak and spreading of infectious diseases depend both on individuals, immunological factors of the population, and environmental influences (such as meteorological and heliogeophysical factors). Identifying the latter is important for understanding the mechanisms of the emergence and development of future pandemics.

Serious efforts in posing and solving this problem were made by A.L. Chizhevsky, the founder of heliobiology in the 1930s (Chizhevsky, 1976, 1995). He analyzed data on influenza epidemics over 500 years and found that they recur on average every 11.3 years; he also compared influenza epidemics with solar activity. It turned out that epidemics occur between the minimum–maximum and maximum–minimum of solar activity. They are located on the curve of solar activity, depending on the action of other factors, although they appear mainly 2–3 years before or after the maximal solar activity. According to his research results, during periods close to maximal solar activity, influenza epidemics spontaneously cover vast territories and cause the greatest human losses. In years of minimal solar activity, only small, spatially isolated influenza epidemics occur.

Over the past decades, the search for mechanisms by which various events and processes on the Sun manifest themselves in the Earth’s biosphere continued. In particular, the possibility of a correlation between the occurrence of influenza epidemics and pandemics and periods of maximal and minimal solar activity was studied. In some studies, a quasi-decadal pattern of epidemic formation and a certain tendency to their appearance during periods of solar maxima are noted (Hope-Simpson, 1978, 1981; Yeung et al., 2006; Vaquero and Gallego, 2007).

The possible impact of changes in heliogeophysical conditions on the occurrence of epidemics and pandemics of influenza in Azerbaijan was considered in (Babayev et al., 2002, 2012). For this purpose, data on the incidence of influenza that cover the Greater Baku region with a population of more than 3 million people for the period 1976–2004, which included more than two 11-year solar cycles, were analyzed and interpreted. The data collected in research institutes involved in the study of infectious diseases, as well as in hospitals, clinics, archives, and emergency and first aid centers were considered. By monthly averaging of empirical data for 1976–2004, the seasonal dependence of the number of patients with influenza was studied. It was shown that the maximal incidence of influenza is reached in February and the minimum occurred in August.

It should be noted that influenza peaks in February were also recorded on seasonal histograms for US regions in 2001–2003 (WHO…, 2003). It is a well-known fact that influenza peaks in winter: typical seasonal influenza activity in the Northern Hemisphere begins in February and often thereafter (Hope-Simpson, 1978). It is assumed that the cause of winter flu epidemics is associated with seasonal fluctuations in vitamin D, which is produced in the skin under the effect of ultraviolet radiation.

The minimal number of influenza cases in the 21st solar cycle was shown to coincides almost exactly with the minimal number of sunspots around 1986 (Babayev et al., 2002, 2012). However, the maximal influenza epidemic in this solar cycle appears in 1976–1977, about two years before the maximal solar activity of 1979–1980. In the next 22nd solar cycle, the maximum influenza epidemic occurred in 1992–1993, ~3 years after the Sun reached its next maximal activity in 1989.

The interpretation of this dependence can be based on the well-known pattern of correlation between sunspot activity and geomagnetic disturbances that is averaged over several solar cycles. There are different solar/interplanetary factors in geomagnetic storms that lead to different peaks observed at solar maximum. It is well known that, in the years of solar maximum, there is usually a double peak in the frequency of geomagnetic storms: most geomagnetic storms occur approximately 2 years before or at the sunspot maximum and approximately 2–3 years after solar maximum (as in case of influenza epidemics) (Bezrodnykh et al., 2018). Geomagnetic activity is more noticeable during the decline phase of the solar cycle.

Based on these facts, it was concluded that solar activity can indirectly affect the occurrence of influenza epidemics through geomagnetic disturbances (Babayev et al., 2012); namely, the maxima in the distribution of influenza epidemics correspond to the maxima of the curve of the average number of geomagnetic storms during 11-summer solar cycle (two peaks 2–3 years before and after the solar maximum).

The authors of (Babayev et al., 2012) explain the minimal spread of influenza epidemics during solar activity minimum as follows. The body after illness (between the maximum and minimum of the solar cycle) acquires natural immunity to this type of virus for several years ahead (1–2 years after influenza A and ~3 years after influenza B). Immunity slowly weakens over time and, after the passage of the minimum of solar activity, a gradual increase in a new burst of the epidemic begins (the “minimum–maximum” stage of the next cycle).

Apparently, a sufficient amount of UV radiation received by the body during the maximal activity of the Sun in the next considered cycle slows down the rate of weakening of the body’s immune defense against this influenza virus and, therefore, the maximal epidemic of the second burst occurs 2–3 years after the maximum activity of the Sun (the maximum–minimum stage of the next considered cycle). Then the body regains natural immunity and the flu epidemic subsides. These arguments are obviously valid only if the antigenic structure of a given type of virus remains unchanged during these periods. In the case of a change in the antigenic structure of the virus, a new burst can begin almost immediately after the previous one.

One alternative hypothesis to explain the cyclical differences in influenza infections could be the effect of vitamin D (Cannell et al., 2006). During solar maximum years, solar flare activity increases the concentration of high-altitude (stratospheric) ozone, which in turn absorbs more solar radiation and thus reduces the amount of ultraviolet radiation actually reaching the Earth’s surface. This fluctuation leads to a proportional decrease in the global level of vitamin D in people, reducing their immunity to the influenza virus.

In light of the above, the possible connection with the solar activity of the current COVID-19 pandemic caused by the spread of the SARS-CoV-2 coronavirus is of interest. Table 1 compiled according to the site https://ru.m.wikipedia.org/wiki/List_of_epidemics_ and_pandemics shows the deadliest epidemics that have already occurred in the 21st century and the corresponding phases of the solar activity cycle (see https://www.spaceweatherlive.com/ru/solnechnaya-aktivnost/solnechnyy-cikl.html).

Table 1.

Major epidemics of the 21st century and solar activity

Name	Development time	Pathogen/Source of infection	Number of deaths	Solar cycle
SARS	2002–2003	Coronavirus SARS-CoV	770 people	Cycle 23 maximum, November 2001
Bird flu	2003	H5N1 – Influenza A/Avian serotype	450 people	On the decline of the 23rd cycle
Swine flu	2009–2010	H1N1 – Influenza A/Swine serotype	200 thousand people	Minimum, beginning of cycle 24, December 2008
Middle East respiratory syndrome	2012–present	Coronavirus MERS-CoV	800 people	Cycle 24 maximum, April 2014
Ebola	2014–2016	Ebola/Wild Animals	11 thousand people	Cycle 24 maximum, April 2014
COVID-19 pandemic	2019–present	Coronavirus SARS-CoV-2	As of March 08, 2022, 41886 people	24 cycle minimum

Of the six deadly viral epidemics, three were at peak activity, one at decline, and two at minimum activity: in 2009–2010, the swine flu epidemics and the 2020 COVID-19 pandemic were preceded by a year-long absence of sunspots.

The transition period between the 24th and 25th cycles was long, while the activity of the Sun reached a minimum: its level in 2019–2020 was the lowest since 1810. According to Chizhevsky, the H1N1 influenza pandemic and the COVID-19 pandemic occurred during the solar minimum and must be qualified as spatially isolated events. The reason for their planetary spread could be apparently an increase in the mobility of people due to the development of all types of passenger transport, which, accordingly, led to the rapid transmission of infection to various distant regions of the world.

It should be noted that hard ultraviolet (UVC) and, to a lesser extent, ultraviolet of medium hardness (UVB) have a bactericidal effect. Only a narrow radiation range of 230–400 nm has an effective bactericidal effect. Quanta with wavelengths in this range are absorbed by nucleic acids, which leads to the destruction of the DNA and RNA structure. Besides being bactericidal, this range has antiviral, antifungal, and spore-killing effects, and it kills the 2020 pandemic-causing SARS-CoV-2 RNA virus.

The epidemic caused by the SARS-CoV-2 coronavirus began around the planet during the solar minimum, as did the swine flu pandemic caused by the spread of the H1N1 virus in 2009, which occurred during a period of weak solar radiation (the period of the previous solar minimum). In (Ivanoviħ, 2020), there is a reference to the research of the Serbian scientist M. Stevanchevich, who discovered a correlation between weak ultraviolet radiation and the appearance of large-scale epidemics of infectious diseases. The ultraviolet radiation of the Sun at the time when the last coronavirus appeared was even weaker than during the spread of swine flu. The lack of ultraviolet radiation, i.e., disinfection of the atmosphere, in both cases caused the spread of the virus in the Northern Hemisphere.

The relation between the COVID-2019 pandemic and a decrease in solar activity and, accordingly, the level of ultraviolet radiation was also noted in (Golubchikov, 2020). It can be assumed that prerequisites are created both for the multiplication of viruses and for reducing the immunity of people under such conditions. A steady decline in ultraviolet is characteristic of the north of Europe, where people traditionally make up for its deficiency by increasing milk consumption. In relatively poor ultraviolet northern regions, milk is considered a kind of substitute for vitamin D.

Three main factors influencing the development of a pandemic—the dynamics of solar activity and galactic cosmic rays, the genogeographic distribution of the population (in particular, haplogroups characteristic of a given area), and the temperature regime of the environment—are considered in (Ragulskaya, 2020, 2021). One of the most significant factors in the spread of the SARS-CoV-2 coronavirus and the level of mortality was shown to be the genogeographic distribution of the population; the level of achievement of collective immunity by vaccination also depends on the genetic composition of the population.

On the European territory of Russia, the dominant haplogroup is R1a, which turned out to be characterized by the rapid development of the epidemic with low mortality and a large number of asymptomatic patients. In the northern regions of Russia, the proportion of the R1a haplogroup is almost halved, giving way to the Nc1 haplogroup. The difference in the genetic composition of the population can also explain the significant difference in the development of the first wave of the COVID-19 epidemic in the cities of Moscow and St. Petersburg, as well as the peculiarities of vaccination and the acquisition of herd immunity in various countries and regions (it is necessary to vaccinate ~80% for haplogroup R1b versus 40% for haplogroup N). The spread of the COVID-19 pandemic showed that, under conditions of a deep minimum of solar activity, the development of epidemiological processes depends on the genogeographic composition of the population and weather conditions much more than on the severity of quarantine measures, the level of medicine, or the age composition of the population.

The features of the bioefficiency of geomagnetic disturbances during the COVID-19 pandemic for March–April 2020 and identified specific space weather factors that affect the sensitivity of the myocardium of healthy volunteers and volunteers with an initial state disorder myocardium due to the COVID-19 pandemic were studied in (Samsonov and Parshina, 2021). Daily monitoring of the symmetry coefficient of the T wave in the phase portrait of the electrocardiogram, the daily Kp index of geomagnetic disturbance, the dynamic pressure of the solar wind, the B_z component of the interplanetary magnetic field, and the radio emission of the Sun with a wavelength of 10.7 cm was carried out.

Two types of response of the cardiovascular system to geomagnetic disturbances were identified: immediate, characteristic of cardiosensitive volunteers, and delayed, characteristic of cardioinsensitive volunteers. The analysis of the data made it possible to determine the combination and significance of the geophysical characteristics of geomagnetic disturbances that cause reactions delayed by 1–2 days of the cardiovascular system in cardio-insensitive volunteers: daily Kp-index by more than 20 arb. units, the dynamic pressure of the solar wind by more than 2.0 nPa, and the negative value of the B_z component of the interplanetary magnetic field.

According to research results (Parshina et al., 2020; Petrikov et al., 2020), a violation of myocardial repolarization processes, indicating a decrease in myocardial adaptive reserves and the development of elements of myocardial dysfunction against the background of increased activity of the mechanisms of sympathetic regulation of the heart, was recorded in 83.4% of healthy volunteer doctors during the COVID-19 pandemic. The authors of these studies also compared the state of the myocardium of healthy volunteers in 2020 with the results of similar studies performed in 2014 and 2019. The rate of myocardial repolarization disorders in 2020 was found to be statistically significantly higher than similar indicators in 2014 and 2019. It was shown that, during the COVID-19 pandemic, the initial state of the heart muscle is extremely important, since it determines the risk of developing myocardial damage in case of infection with coronavirus and increases the risk of hospital mortality (Capotosto et al., 2020).

Since the start of the epidemic, other studies emerged on the properties of the COVID-19 pandemic. For example, models were developed and a forecast for the development of the pandemic was given in (Zenchenko and Breus, 2020; Matveev, 2020; Sizikova et al., 2020; Supotnitsky, 2020; Chan et al., 2020; Hui et al., 2020; Kiznys et al., 2020; Mattoni et al., 2020; Nicastro et al., 2020; Wu et al., 2020; Hunting et al., 2021; Zenchenko and Breus, 2021). The spread of the COVID-19 pandemic in Russia with its course in China, Italy, Germany, and the United States was compared based on a study of the dynamics of epidemiological characteristics. It is concluded that the COVID-19 epidemic in Russia is different in that its center became the capital region: Moscow and Moscow oblast, which plays a decisive role in the social, economic, political, and cultural life of Russia and is the largest center of transport communications. The spread of the epidemic was mathematically described using the SIR (susceptible, infected, recovered) model proposed by Scottish epidemiologists W. Kermack and A. McKendrick (Kermack and McKendrick, 1927).

In this paper, environmental factors related to the impact of heliogeophysical activity on the COVID-19 epidemic in Moscow will be considered and discussed.

USED DATA

With regard to the level of heliogeophysical activity and the state of human physiological health, two types of quantifiable indicators are given in the literature (Palmer et al., 2006).

1. Indirect indicators: epidemiological data showing the temporal and spatial distribution of certain events or health disorders associated with a significant number of subjects over several years. Such indicators include the time distribution of calls to ambulance teams, the number of hospitalizations, etc.

2. Direct indicators: physiological parameters that can be objectively checked and are determined either directly (in vivo) on the object (heart rate and variability, blood pressure, microcirculation parameters, and reaction time) or using laboratory diagnostics or tissue studies (in vitro).

This paper examines the heliogeophysical conditions of the pandemic over the period March 2020–February 2022, as well as the short-term impact of magnetospheric storms and substorms on human health during an epidemic.

Data on the number of daily infections and deaths are taken from the site https://ru.wikipedia.org/ wiki/Distribution_COVID-19_in_Moscow; K-indices are taken from the IZMIRAN website, the Moscow Observatory (www.izmiran.ru); ionospheric data are taken from the site of the Fedorov Institute of Applied Geophysics (www.ipg.ru); and UV index values are taken from the site https://www.pogodaonline.ru/weather/maps/city?WMO=27612&CONT= ruru&LAND=RS&ART=UVINDEX&LEVEL=150.

DYNAMICS OF THE COVID-19 PANDEMIC IN MOSCOW IN 2020–2021

Figure 1 shows the dynamics of the daily number of infections and variations in the UV index, the time course of the number of deaths, and the daily values of the ΣK index (IZMIRAN Observatory, Troitsk) since the beginning of the pandemic was announced in Moscow on March 2, 2020.

Fig. 1.

(a) Number of daily infections with coronavirus (1) and the ultraviolet radiation index (2), (b) number of deaths, and (c) the course of the daily ΣK-index in Moscow in 2020–2022. The arrows show the periods of decrease in geomagnetic activity.

The first five waves of an increase in the number of infections and deaths are clearly visible. The peak incidence in 2020 and 2021 is in April–May and October–January. In June–July 2021, an “out-of-season” wave of a new strain of coronavirus (delta) arose, and a rapidly spreading and crowding out other varieties of the omicron strain appeared at the end of December of the same year.

The pandemic arose and continues during a deep minimum of solar activity. As follows from data shown in Fig. 1, the UV index does not exceed six units, and the 1st and 2nd waves of infections began at values of 1–2 units, i.e., at very low levels of ultraviolet radiation. Figure 1c shows a spline solid curve ΣK(t) calculated using exponential smoothing. The arrows show the periods of decrease in geomagnetic activity, which correspond to bursts of an increase in the number of infections.

Figure 1 clearly illustrates the antiphase of the number of infections and deaths with the course of geomagnetic activity: over the entire considered period, an increase in the number of infections and deaths clearly correlates with a long-term (3 to 5 months) decrease in geomagnetic activity. This fact, apparently, is quite an important component, if not the main one, in explaining the observed effect of the impact of a low level of the geomagnetic field on the human body during a pandemic, in particular, on the immune and respiratory systems.

If a person is shielded from a magnetic field, this immediately affects his condition: blood vessels constrict, metabolic processes are disturbed, fatigue increases, and the adaptive capabilities of the cardiovascular and immune systems decrease (Shumilov et al., 2003; Pokhodzey et al., 2012). At a low magnetic field strength, the immune system of any organism is inactive. In (O’Connor, Persinger, 1997), a strong nonlinear correlation between sudden infant death syndrome from respiratory arrest (SIDS) in apparently healthy infants and geomagnetic activity was shown using the example of the province of Ontario, Canada. An increase in the number of SIDS cases is observed at levels of geomagnetic disturbances of 11–20 and 31–40 nT. This can serve as confirmation of the impact of a decrease from a certain level of geomagnetic activity on human health.

Throughout their life, every person is exposed to the constant influence of the geomagnetic field. Prolonged exposure to a weakened geomagnetic field on the human body can lead to a decrease in the physiological, biochemical, and morphological parameters of its functioning. In particular, it affects the nervous, hematopoietic, neuroendocrine, immune, and reproductive systems and the development of the fetus. A decrease in the intensity of the geomagnetic field also leads to impaired blood circulation by changing the mechanism of transporting oxygen and nutrients to organs and tissues (Gruzin et al., 2015).

Both repeated and singular weakening of the geomagnetic field cause in the body of healthy people pronounced compensatory-adaptive reactions such as

(i) a significant increase in the low-frequency contribution to the total power of the cardiorhythm spectrum, from 26 to 38%;

(ii) a decrease according to rheoencephalography by 18–25% of the blood filling of the cerebral vessels.

Unlike healthy people, there is a significant (from 35 to 46%) increase in the share of the very low-frequency spectrum in the total heart rate power and an increase in the level of diastolic blood pressure by an average of 16% in patients with arterial hypertension. This confirms the effect of the Earth’s magnetic field on the functional state of the cardiovascular and central nervous systems (Devitsin, 2005).

The expressiveness and direction of the detected shifts in the body have a certain dependence on the duration of stay under conditions of a decrease in geomagnetic activity. For example, upon an increase in the duration of exposure, an increase in the adverse effect was usually noted while the functional state of the reproductive and immune systems and blood did not return to normal even in the period after the cessation of exposure (Berezin et al., 2015).

DYNAMICS OF CORONAVIRUS INFECTIONS DURING MAGNETIC DISTURBANCES

In the previous section, the effect of heliogeophysical conditions on the development of the pandemic was considered throughout the entire considered period (March 2020–February 2022) using daily data on the number of coronavirus infections and the number of deaths. In this section, we analyze short-term (from one to several days) changes in these parameters during periods of magnetospheric disturbances.

Active processes on the Sun and in the magnetosphere lead to geomagnetic and ionospheric disturbances. Upon minimal solar activity, most storms are recurrent. The reason for such storms is the arrival of high-speed solar wind streams flowing from coronal holes to the Earth. The pandemic broke out during an extended solar minimum; flare activity was also minimal: mostly class C flares occurred and they were not geoeffective. Geomagnetic disturbances caused by high-speed plasma flows were also noted, but were not strong: K-indices rarely reached 5. In the ionosphere, their own disturbances occurred both simultaneously with magnetic storms and against the background of a quiet geomagnetic field.

Several periods were selected for analysis when geomagnetic and ionospheric disturbances were observed. Figure 2 shows examples of bursts in the number of (a) diseases N_ds and (b) deaths N_dt during three periods of the pandemic: spring 2020, summer 2021, and winter 2021. Figures 2a and 2b show by a dotted line the dependencies obtained by the exponential smoothing method and reflecting the background state of the course of the pandemic. The change in (c) the daily ΣK-index and (d) the δfoF2 index of ionospheric disturbances during these periods are also shown; periods are considered disturbed when |δfoF2| ≥ 20%. The moments of geomagnetic disturbances are marked with arrows. In Figs. 2a and 2b, areas of increase in the number of diseases and deaths that correlate in time with the onset of disturbances are shaded. It can be seen that these days the morbidity and mortality are actually increasing when compared to background values.

Fig. 2.

(a) Number of coronavirus infections, (b) number of deaths, (c) change in the ΣK-index, and (d) index of ionospheric disturbances δfoF2 in Moscow during periods of geomagnetic disturbances amid the COVID-19 pandemic. Arrows indicate magnetic storms (see also Table 2). See the text for further explanations.

Table 2 shows the maximal increase in the number of coronavirus infections ΔN_ds and deaths ΔN_dt during geomagnetic disturbances at the time of the COVID-19 pandemic in Moscow. It follows from the data presented in the table that the values of ΔN_ds and ΔN_dt at this time exceed the standard deviations (RMS). When estimating the statistical significance of the increase in N_ds and N_dt during disturbances, the Cramer–Welch criterion was used while differences were considered significant at T_0.05 > 1.96. The T_0.05 values are also given in Table 2.

Table 2.  .

Values of indicators of coronavirus infection and deaths in Moscow during geomagnetic disturbances amid the pandemic

Period	RMS	Storm number (see Fig. 2)
		1		2		3		4
		ΔNds	Т	ΔNds	Т	ΔNds	Т	ΔNds	Т
Mar 2–Apr 4, 2020	450	2000	2.83	1000	2.72	–	–	–	–
Jan 1–Feb 1, 2021	731	1000	2.56	2000	2.41	–	–	–	–
Jun 7–Jul 16, 2021	768	3000	2.34	3000	2.69	1000	2.11	1000	2.07
Period	RMS	Storm number (see Fig. 2)
		1		2		3		4
		ΔNdt	Т	ΔNdt	Т	ΔNdt	Т	ΔNdt	Т
Mar 2–Apr 4, 2020	8	10	2.33	10	2.12	–	–	–	–
Jan 1–Feb 1, 2021	6	10	2.16	20	2.41	–	–	–	–
Jun 7–Jul 16, 2021	6	10	2.14	15	2.39	40	2.13	10	2.01

A dash indicates no data.

A practically healthy organism and the organism of a sick person react differently to external stress factors. The conditions that develop during disturbances are difficult even for a healthy organism, while a sick organism is sometimes unable to cope with the problem of adaptation, since its reserve capabilities are depleted. Accordingly, as can be seen in Figs. 2b and 2c, with a delay of one to several days, the number of deaths increases compared to the background values.

Note that, during the COVID-19 epidemic, only a part of the population was affected by heliogeomagnetic disturbances, and this fraction is estimated at 10–15% of the total population of Moscow.

The effect of heliogeophysical disturbances on the human body is studied by scientists at various scientific centers of the world. The main results of these studies obtained over the past 30 years are summarized in (Palmer et al., 2006). The various parameters used as indicators of human health, the methodology of statistical analysis, and the mechanisms of influence are considered. It is noted that the effect of geophysical disturbances on the body for the most part does not depend on the intensity of storms. The nature and degree of manifestation of responses to such a natural stress factor as a geomagnetic storm are determined by the individual adaptive abilities of the organism (Agadzhanyan and Makarova, 2001).

As for the mechanisms of this effect, they are apparently the same during a pandemic as under normal conditions. Several options are discussed in the literature.

(1) Melatonin plays an important role in one or more of the mechanisms that relate environmental conditions to human health. Some studies confirm the hypothesis that geomagnetic disturbances change the melatonin level in the human body (Rapoport et al., 1997).

(2) The Schumann resonance hypothesis is also considered as a possible mechanism relating geomagnetic activity and the unfavorable state of human health (Fdez-Arroyabe et al., 2020). The frequencies of the Schumann signals are determined by the characteristics of the Earth–ionosphere cavity. It is hypothesized that the uptake of these signals by the human brain may modulate the amount of melatonin produced and secreted by the pineal gland (Cherry, 2002).

(3) Different physical mechanisms operate in different phases of perturbations. In the initial period of the storm, one of the physical mechanisms of the action of external weak periodic signals against the noise background can be the stochastic resonance. The second and third harmonics of the resonance of brain nerve structures are due to the first harmonics of oscillations in the ionospheric Alfven resonator, which are able to synchronize or desynchronize the rhythms of electromagnetic oscillations of blood cells (Belyaev et al., 1989; Varakin et al., 2013). At the stage of development of the geomagnetic storm, the possibility of a direct effect of a change in the electromagnetic field on the cells of the human body is discussed (Breus et al., 2016).

Obviously, the ambiguity of the response of complex nonlinear systems, which include the human body, to weak external effects of a heliogeophysical nature depends both on the properties of the influencing factor and on the state of the system itself. In healthy individuals, the changes associated with perturbations are reversible and have an adaptive character. However, in people infected with coronavirus, these changes are likely to lead to the disease progression and death.

CONCLUSIONS

Obviously, the emergence and spread of epidemics and pandemics mainly depend on genetic, physiological, and social factors, but the timing of their appearance and further development may indicate that space weather agents are also involved. In recent decades, it has been convincingly proven that the natural geomagnetic field should be considered one of the most important environmental factors of fundamental importance in the formation, development, and regulation of life on Earth.

The COVID-19 pandemic caused by the spread of the SARS-CoV-2 coronavirus arose at a time when solar activity was minimal. Based on official data on morbidity in Moscow, the analysis carried out in this study showed that heliogeophysical activity has a direct effect on the occurrence and course of infectious diseases. There is a significant relation between the number of outbreaks in the number of infections and deaths in the city during a pandemic and prolonged periods of reduced geomagnetic activity. Thus, reduced geomagnetic activity has a biological effect, causing the development of adverse changes in the human body.

It is also shown that short-term increases in geomagnetic and ionospheric activity during heliogeophysical disturbances additionally increase both the number of infections and the number of deaths.

The results of the analysis show that the number of people infected during the first five waves of coronavirus did not exceed 10% of the total population of Moscow, while only 10–15% of the inhabitants were exposed to heliogeophysical disturbances.

Although the reality of the influence of heliogeophysical conditions on the course of the pandemic is obvious, further consolidation of the scientific community is required to conduct additional research to find mechanisms that could explain this relation. A coordinated analysis of national medical databases to systematically correlate epidemics with changes in geomagnetic and solar activity may provide an influx of new data that will confirm and explain current results.

FUNDING

This work was supported by the State Task of the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences.

CONFLICT OF INTERESTS

The author declares that he has no conflict of interest.