October 22, 2020
Solar and Geomagnetic Activity and their Effect on Human Physiology
Aurora Borealis - Stockholm, Sweden: Photo by Anders Jildén (@AndersJilden)
by James Odell, OMD, ND, L.Ac.
Solar and Geomagnetic Activity (S-GMA) is a disruption of the geomagnetic field induced by changes in electrical currents in the magnetosphere and ionosphere. It is the main cause of such changes in the flow of solar flares, coronal mass ejections, and high-speed wind streams that interact with the earth’s geomagnetic field and add energy to the magnetosphere-ionosphere current system. Geomagnetic storms, substorms, and pulsations are the most noteworthy manifestations of geomagnetic activity. Numerous studies have now identified significant physical, biological, and health effects associated with changes in S-GMA. Significant correlations between hospital admissions and health registries and S-GMA have been observed for a long time. Now, there is a large body of research that correclates S-GMA with biological effects and human health effects.
The ionosphere is a layer of plasma, a term that describes highly ionized gases threaded by magnetic fields, which surround the Earth. The charged particles in the plasma can spiral around the magnetic field lines and travel along with it, creating auroras as high-energy particles flow along the field lines to the Earth’s magnetic poles. This “magnetohydrodynamic process” was described by Nobel Prize Laureate Hannes Olof Gösta Alfvén to explain how low-frequency waves that propagate along magnetic field lines are created.1
Standing waves in the magnetosphere involve several magnetic field lines, with lengths several times the Earth’s radius, which is excited and oscillates at their resonant frequency, similar to a plucked guitar string. Longer field lines have a lower resonant frequency, whereas shorter field lines resonate at a higher frequency. Field lines with more or heavier particles spiraling around them tend to have lower frequencies. Changes in solar wind velocity or the polarity and orientation of the interplanetary magnetic field may have dramatic effects on the waves, as measured on the Earth’s surface.2
Many studies have been published describing a broad range of physiological, psychological, and behavioral changes associated with changes or disturbances in geomagnetic activity and solar activity. Studies have shown that increased amplitudes of field line resonances can particularly affect the cardiovascular system, most likely because their frequencies are in the same range as the primary rhythms found in the cardiovascular and autonomic nervous systems.
In some countries, magnetic field disturbances are included in public weather forecast reports. (Space weather news may be accessed at www.spaceweather.com) On a larger societal scale, increased rates of violence, crime, social unrest, revolutions, and frequency of terrorist attacks have been linked to the solar cycle and the resulting disturbances in the geomagnetic field.3, 4, 5
Increased solar activity has not only been associated with social unrest, it is also associated with the periods of the greatest human flourishing with clear spurts of innovation and creativity in architecture, arts, sciences, and positive social change, as well as with variable human performance in the financial markets.6, 7, 8
Over the last few years, various researches have reached the conclusion that cosmic ray variations and geomagnetic disturbances impact human physiology. These studies build on observations made by the famed astronomer Alexander Chizhevsky during World War I.9 Chizhevsky observed that social conflict and wars intensify during peak solar flare periods and that major human events and behaviors closely follow the cycle of the sun.10 This eventually led to the hypothesis that some unknown solar forces affect human health and behavior, providing a provocative link between events occurring in our solar system and life on Earth.
Geomagnetic storms, i.e. extreme fluctuations of the globally recorded geomagnetic field, are known to have the greatest biological influence of all forms of geomagnetic activity. During a geomagnetic storm, the F2 layer of the ionosphere becomes unstable, fragments, and may even vanish. Auroras become visible in the northern and southern pole regions of the planet. The F2 layer of the ionosphere exists from approximately 220 to 800 km (140 to 500 miles) above the surface of the Earth. F2 is the principal reflecting layer for telecommunications during both day and night. Since the ionosphere is heated and distorted during a geomagnetic storm (commonly referred to as a solar storm) long-range radio communication that relies on sub-ionosphere reflection can be difficult or impossible, and global-positioning system (GPS) communications can be compromised. Not only can solar storms cause a temporary disturbance of the Earth’s magnetosphere impacting telecommunications, but human and animal bioregulatory systems may also be adversely affected.
The layers above the Earth are the troposphere, the stratosphere, and the ionosphere. The ionosphere ranges approximately between 90 to 250 km above the Earth.
The sun is a magnetic variable star that fluctuates on times scales ranging from a fraction of a second to billions of years. Credits: NASA
The Sun unleashed a powerful flare on 4 November 2003. The Extreme ultraviolet Imager in the 195A emission line aboard the SOHO spacecraft captured the event.Credits: ESA&NASA/SOHO
A solar flare is an intense burst of radiation coming from the release of magnetic energy associated with sunspots. Flares are our solar system’s largest explosive events. They are seen as bright areas on the sun, and they can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, at most every wavelength of the spectrum. The primary ways we monitor flares are in x-rays and optical light. Flares are also sites where particles (electrons, protons, and heavier particles) are accelerated.
Solar activity associated with space weather can be divided into four main components: solar flares, coronal mass ejections, high-speed solar wind, and solar energetic particles.
Solar flares impact Earth only when they occur on the side of the sun facing Earth. Because flares are made of photons, they travel out directly from the flare site, so if we can see the flare, we can be impacted by it.
Coronal mass ejections, also called CMEs, are large clouds of plasma and magnetic fields that erupt from the sun. These clouds can erupt in any direction and then continue in that direction, plowing right through the solar wind. Only when the cloud is aimed at Earth will the CME hit Earth and therefore cause impacts.
High-speed solar wind streams come from areas on the sun known as coronal holes. These holes can form anywhere on the sun and usually, only when they are closer to the solar equator, so the winds they produce impact Earth.
Solar energetic particles are high-energy charged particles, primarily thought to be released by shocks formed at the front of coronal mass ejections and solar flares. When a CME cloud plows through the solar wind, high velocity solar energetic particles can be produced and because they are charged, they must follow the magnetic field lines that pervade the space between the Sun and the Earth. Therefore, only the charged particles that follow magnetic field lines that intersect the Earth will result in impacts.
The Earth’s magnetosphere is part of a dynamic, interconnected system that reacts to solar, planetary, and interstellar conditions. It is generated by the convective motion of charged, molten iron deep below the surface in Earth’s outer core. Constant solar-wind bombardment compresses the sun-facing side of our magnetic field. The sun-facing side, or dayside, spans from six to 10 times the radius of the Earth. The side of the magnetosphere that faces away from the sun – the nightside – is stretched out into an immense magnetotail that fluctuates in length and can measure hundreds of Earth radii well beyond the 60 Earth radii of the Moon. When a coronal mass ejection or high-speed stream lands on Earth it buffets the magnetosphere. If the incoming solar magnetic field is directed southward it interacts strongly with the oppositely oriented magnetic field of the Earth. The Earth’s magnetic field is then peeled open like an onion that allows energetic solar wind particles to migrate down the field lines to reach the atmosphere over the poles. OnEarth’s surface, a magnetic storm is seen as a rapid drop in the Earth’s magnetic field strength. These storms have a major effect on the geomagnetic field line resonances which interact with many of the Earth’s biological regulatory organisms (humans and animals).
Solar Wind Colliding with Earth’s Magnetic Field
The Schumann Resonances and Solar Radiation
The Schumann resonances (or frequencies) are quasi-standing electromagnetic waves that exist in the cavity (or space) between the surface of the Earth and the ionosphere. In 1952, German physicist Professor Winfried Otto Schumann of the Technical University of Munich began attempting to answer whether the Earth itself has a frequency – a “pulse”. His assumption about the existence of this frequency came from his understanding that when a sphere exists inside another sphere, electrical tension is created. Since the negatively charged Earth exists inside the positively charged ionosphere, there must be tension between the two, giving the Earth a specific frequency. Through a series of calculations, he was able to deduce a frequency he believed was the pulse of the Earth-ionosphere space. Two years later, in 1954, Schumann and Herbert König reported reliable and predictable frequencies in the atmosphere that existed in the cavity (or space) between the surface of the Earth and the ionosphere. Research has shown that several frequencies occur between 6 and 50 Hz (cycles per second), the fundamental frequency they found to be 7.83 Hz.11 It is well established that the Schumann frequencies have directly affected human physiology over thousands of years. Though 7.83 is considered the fundamental Schumann resonance, other frequencies occur specifically 7.8, 14, 20, 26, 33, 39 and 45 Hertz, with a daily variation of about +/- 0.5 Hertz (Hz) These frequencies function as a background frequency influencing and resonating with the biological circuitry of much of the life on Earth. These frequencies directly overlap those of the human brain, autonomic nervous system, and cardiovascular system.12, 13, 14, 15, 16, 17
It has also been established that the amplitude of the Schumann Resonance’s modes is affected by events due to solar activity.18 Thus, it is proposed that solar and geomagnetic activity may alter Schumann frequencies, and may be one mechanism to explain its effect on human physiology. Human regulatory systems are designed to adapt to daily and seasonal climatic and geomagnetic variations. However, sharp changes in solar and geomagnetic activity, particularly geomagnetic storms, can stress these regulatory systems This then results in alterations in melatonin/serotonin balance, blood pressure, immune system, reproductive, cardiac, and neurological processes.
The Schumann resonance signal is found to be extremely highly correlated with S-GMA indices of sunspot number and the Kp index. The Kp-index describes the disturbance of the Earth’s magnetic field caused by the solar wind. The faster the solar wind blows, the greater the turbulence. The index ranges from 0, for low activity, to 9, which means that an intense geomagnetic storm is underway. The physical mechanism is the ionospheric D-region ion/electron density that varies with S-GMA and forms the upper boundary of the resonant cavity in which the Schumann Resonance signal is formed. This provides strong support for identifying the Schumann Resonance signals as the S-GMA biophysical mechanism and supports the classification of S-GMA as a natural bioregulatory hazard.
Heart Rate Variability and Solar and Geomagnetic Activity
Heart Rate Variability (HRV) refers to beat-to-beat alterations in heart rate as measured by periodic variation in the R–R interval. HRV provides a non-invasive method for investigating the autonomic nervous system’s input on physiology. It quantifies the amount by which the R–R interval or heart rate changes from one cardiac cycle to the next.
The autonomic nervous system transmits impulses from the central nervous system to peripheral organs and regulates bodily functions, such as the heart rate, blood pressure, digestion, respiratory rate, pupillary response, urination, and sexual arousal. In normal individuals, without cardiac disease, the heart rate has a high degree of beat-to-beat variability – increased HRV. As the body becomes ill, HRV decreases. Reduced heart rate variability carries an adverse prognosis in patients who have survived an acute myocardial infarction.19, 20
In attempt to answer the question as to how S-GMA affects human physiology, researchers have turned to HRV to assess the autonomic nervous system. Their findings suggest that our nervous systems are well attuned to the energetic fluctuations that ripple through our solar system.
The heart and cardiovascular system has always been considered the main biological target of S-GMA. Numerous studies now have demonstrated that S-GMA can alter heart rate variability and cardiac rhythm. Multiple studies have also demonstrated significant decreases in HRV during magnetic storms indicating a possible mechanism linking geomagnetic activity with increased incidence of coronary disease and myocardial infarction, and suggests that the cardiovascular system is a clear target for the impact of geomagnetic disturbances.21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34
It has been observed that the low and extremely low-frequency electromagnetic fields generated by S-GMA destabilize the heartbeat, leading to sudden death or infarction in susceptible or compromised individuals. Medical experts have finally explained why heart attacks take a heavy toll before a magnetic storm – because micro variations begin 24 hours before the storm.35, 36, 37, 38, 39
A 2017 study demonstrated that daily autonomic nervous system activity not only responds to changes in solar and geomagnetic activity but is synchronized with time-varying magnetic fields associated with geomagnetic field-line resonances and Schumann resonances. The authors concluded, “ A likely explanation for how solar and geomagnetic fields can influence human nervous system activity is through a resonant coupling between our nervous systems and geomagnetic frequencies (Alfvén waves), or ultra-low frequency standing waves in the earth-ionosphere resonant cavity (Schumann resonances) that overlap with physiological rhythms.”40
In a 2018 long-term study, scientists investigated relationships between solar and magnetic factors and the timing and lags of autonomic nervous system responses using HRV to changes in solar and geomagnetic activity.30 Heart rate variability was recorded for 72 consecutive hours each week over a five-month span in 16 participants in order to analyze ANS responses during normal background environmental periods. Overall, this study confirmed that daily ANS activity responds to changes in geomagnetic and solar activity during periods of normal undisturbed activity and was initiated at different times after the changes in the various environmental factors and persisted over varying time periods. The increase in solar wind intensity was correlated with increases in heart rate, which was interpreted as a biological stress response. The findings support the hypothesis that energetic environmental phenomena influence psychophysical processes that can affect people in different ways depending on their sensitivity, health status, and capacity for self-regulation.41
Studies have also shown that blood pressure changes occur during solar storms. Specifically, it was noted that the shifts in blood pressure parameters were higher during the solar minimum and the ascending phase of solar cycle than during the solar maximum, due to the higher prevalence of intense geomagnetic storms during those periods.42, 43, 44, 45
A solar cycle occurs over a period of approximately 11 years, but it may be up to 14 or 15 years. During any given solar cycle, the number of sunspots rises to a maximum (solar maximum) and falls to a minimum (Solar Minimum). Solar minimum is the time of least solar activity in the 11-year solar cycle of the Sun. During this time, the activity of sunspots and solar flares diminishes, and often does not occur for days at a time.
Studies show that increased Solar and Geomagnetic Activity influencing Schumann resonances and intensity power are all associated with alterations in HRV – reducing HRV – indicating the autonomic nervous system responds quickly to changes in these environmental factors.
Circadian Rhythms (Hormone Secretion) and Solar and Geomagnetic Activity
Physiological damage to human health caused by Solar and Geomagnetic Activity has been shown to affect other regulatory systems, in particular certain endocrine (hormonal) glands.46 Circadian rhythms are the cycles that tell the body when to sleep, wake, and eat—the biological and psychological processes that oscillate in predictable patterns each day. This internal clock is influenced by external cues, like sunlight and temperature, which help determine whether one feels energized or exhausted at different times of the day. The primary endocrine system involved in the diurnal (circadian) cycle is the melatonin/serotonin system initially operating between the pineal gland and the hypothalamus. The portion of the hypothalamus which contains the “biological clock” is called the suprachiasmatic nucleus. There are high-affinity melatonin and serotonin receptors in the brain and throughout the central nervous system that regulate numerous biological functions. Additionally, the cardiovascular system is regulated by melatonin receptors in the heart, arteries, and lungs.47, 48, 49
Various melatonin hypotheses of Solar and Geomagnetic Activity have suggested that temporal variation in the geomagnetic field (solar storms) may be influencing the body’s circadian rhythms, particularly melatonin production.50, 51 When the melatonin system becomes dysregulated, many physical and non-physical functions suffer.
One study has shown evidence for the negative influence of magnetic disturbances and solar storms on melatonin production in patients with ischemic heart disease.52 Another study demonstrated that solar storms lower melatonin production in patients with essential hypertension.53
The hypothesis promoted and supported by numerous studies here is that the Schumann resonance signal is a plausible biophysical mechanism for linking S-GMA levels to biological and human health effects. This operates by being resonantly absorbed by brain systems and altering the autonomic nervous system as well as serotonin/melatonin balance. Continued studies and confirmation of this hypothesis will strengthen the proposal that S-GMA is a natural threat for humans, animals, and other organisms.
1. Alfvén, Hannes. Cosmical electrodynamics. Рипол Классик, 1963.
2. McPherron, Robert L. “Magnetic pulsations: their sources and relation to solar wind and geomagnetic activity.” Surveys in Geophysics 26, no. 5 (2005): 545-592.
3. Ertel, S. “” Space Weather and Revolutions. Chizevsky´ s Sociobiological Claim Scrutinized.” Studia Psychologica 38.1/2.” (1996).
4. Ertel, S. “Cosmophysical correlations of creative activity in culture history.” Biophysics 43, no. 4 (1998): 696-702.
5. Krivelyova, A. & Robotti, C. Playing the field: Geomagnetic storms and international stock markets. (Working paper, Federal Reserve Bank of Atlanta, 2003).
6. Ertel, S. “Cosmophysical correlations of creative activity in culture history.” Biophysics 43, no. 4 (1998): 696-702.
7. Lean, Judith. “Evolution of the Sun’s spectral irradiance since the Maunder Minimum.” Geophysical Research Letters 27, no. 16 (2000): 2425-2428.
8. Gorbanev, Mikhail. “Can solar activity influence the occurrence of economic recessions?.” (2015): 235-264.
9. Gumarova, L., G. Cornelissen, D. Hillman, and F. Halberg. “Geographically selective assortment of cycles in pandemics: meta-analysis of data collected by Chizhevsky.” Epidemiology & Infection 141, no. 10 (2013): 2173-2184.
10. Payne, Buryl. “Solar Cycle and Wars.”
11. Besser, BP “Synopsis of the historical development of Schumann resonances.” Radio Science 42, no.02 (2007): 1-20.
12. Pobachenko, S. V., A. G. Kolesnik, A. S. Borodin, and V. V. Kalyuzhin. “The contingency of parameters of human encephalograms and Schumann resonance electromagnetic fields revealed in monitoring studies.” Biophysics 51, no. 3 (2006): 480-483.
13. Price, Colin, and Alexander Melnikov. “Diurnal, seasonal and inter-annual variations in the Schumann resonance parameters.” Journal of atmospheric and solar-terrestrial physics 66, no. 13-14 (2004): 1179-1185.
14. Rapoport, S. I., N. K. Malinovskaia, V. N. Oraevskii, F. I. Komarov, A. M. Nosovskii, and L. Vetterberg. “Effects of disturbances of natural magnetic field of the Earth on melatonin production in patients with coronary heart disease.” Klinicheskaia meditsina 75, no. 6 (1997): 24-26.
15. Otsuka, Kuniaki, Germaine Cornelissen, Tsering Norboo, Emiko Takasugi, and Franz Halberg. “Chronomics and “glocal”(combined global and local) assessment of human life.” Progress of Theoretical Physics Supplement 173 (2008): 134-152.
16. Hamer, J. R. “Biological entrainment of the human brain by low frequency radiation.” Northrop Space Labs 36 (1965): 65-199.
17. Oraevskiĭ, V. N., T. K. Breus, R. M. Baevskiĭ, S. I. Rapoport, V. M. Petrov, Z. H. V. Barsukova, and A. T. Rogoza. “Effect of geomagnetic activity on the functional status of the body.” Biofizika 43, no. 5 (1998): 819.
18. Pazos, M., B. Mendoza, P. Sierra, E. Andrade, D. Rodríguez, V. Mendoza, and R. Garduño. “Analysis of the effects of geomagnetic storms in the Schumann Resonance station data in Mexico.” Journal of Atmospheric and Solar-Terrestrial Physics 193 (2019): 105091.
19. Malik, Marek, and A. John Camm. “Heart rate variability.” Clinical cardiology 13, no. 8 (1990): 570-576.
20. Acharya, U. Rajendra, K. Paul Joseph, Natarajan Kannathal, Choo Min Lim, and Jasjit S. Suri. “Heart rate variability: a review.” Medical and biological engineering and computing 44, no. 12 (2006): 1031-1051.
21. Baevsky, R. M., V. M. Petrov, G. Cornelissen, F. Halberg, K. Orth-Gomer, T. Akerstedt, K. Otsuka et al. “Meta-analyzed heart rate variability, exposure to geomagnetic storms, and the risk of ischemic heart disease.” (1997): 201-206.
22. Caswell, Joseph M., Manraj Singh, and Michael A. Persinger. “Simulated sudden increase in geomagnetic activity and its effect on heart rate variability: Experimental verification of correlation studies.” Life sciences in space research 10 (2016): 47-52.
23. Cornélissen, Germaine, Franz Halberg, Tamara Breus, Elena V. Syutkina, Roman Baevsky, Andi Weydahl, Yoshihiko Watanabe et al. “Non-photic solar associations of heart rate variability and myocardial infarction.” Journal of atmospheric and solar-terrestrial physics 64, no. 5-6 (2002): 707-720.
24. Chernouss, Sergey, Antoly Vinogradov, and Elvira Vlassova. “Geophysical hazard for Human health in the circumpolar Auroral Belt: evidence of a relationship between heart rate variation and electromagnetic disturbances.” Natural hazards 23, no. 2-3 (2001): 121-135.
25. Dimitrova, S., I. Angelov, and E. Petrova. “Solar and geomagnetic activity effects on heart rate variability.” Natural hazards 69, no. 1 (2013): 25-37.
26. Dimitrova, S., E. S. Babayev, F. R. Mustafa, I. Stoilova, T. Taseva, and K. Georgieva. “Geomagnetic storms and acute myocardial infarctions morbidity in middle latitudes.” Sun Geosph 4 (2009): 72-78.
27. Gmitrov, J., and C. Ohkubo. “Geomagnetic field decreases cardiovascular variability.” Electro-and Magnetobiology 18, no. 3 (1999): 291-303.
28. Giannaropoulou, E., M. Papailiou, H. Mavromichalaki, M. Gigolashvili, L. Tvildiani, K. Janashia, P. Preka-Papadema, and Th Papadima. “A study on the various types of arrhythmias in relation to the polarity reversal of the solar magnetic field.” Natural hazards 70, no. 2 (2014): 1575-1587.
29. Mavromichalaki, H., M. Papailiou, S. Dimitrova, E. S. Babayev, and P. Loucas. “Space weather hazards and their impact on human cardio-health state parameters on Earth.” Natural hazards 64, no. 2 (2012): 1447-1459.
30. McCraty, Rollin, Mike Atkinson, Viktor Stolc, Abdullah A. Alabdulgader, Alfonsas Vainoras, and Minvydas Ragulskis. “Synchronization of human autonomic nervous system rhythms with geomagnetic activity in human subjects.” International journal of environmental research and public health 14, no. 7 (2017): 770.
31. Otsuka, K., G. Cornélissen, A. Weydahl, B. Holmeslet, T. L. Hansen, M. Shinagawa, Y. Kubo et al. “Geomagnetic disturbance associated with decrease in heart rate variability in a subarctic area.” Biomedicine & pharmacotherapy 55 (2000): s51-s56.
32. Otsuka, K., Y. Ichimaru, G. Cornelissen, A. Weydahl, B. Holmeslet, O. Schwartzkopff, and F. Halberg. “Dynamic analysis of heart rate variability from 7-day Holter recordings associated with geomagnetic activity in subarctic area.” In Computers in Cardiology 2000. Vol. 27 (Cat. 00CH37163), pp. 453-456. IEEE, 2000.
33. Otsuka, K., T. Yamanaka, G. Cornelissen, T. Breus, S. M. Chibisov, R. Baevsky, F. Halberg, J. Siegelova, and B. Fiser. “Altered chronome of heart rate variability during span of high magnetic activity.” Scripta Medica (Brno) 73 (2000): 111-116.
34. Watanabe, Y., G. Cornélissen, F. Halberg, K. Otsuka, and S-I. Ohkawa. “Associations by signatures and coherences between the human circulation and helio-and geomagnetic activity.” Biomedicine & pharmacotherapy 55 (2000): s76-s83.
35. Jaruševičius, Gediminas, Tautvydas Rugelis, Rollin McCraty, Mantas Landauskas, Kristina Berškienė, and Alfonsas Vainoras. “Correlation between changes in local earth’s magnetic field and cases of acute myocardial infarction.” International journal of environmental research and public health 15, no. 3 (2018): 399.
36. Breus, Tamara Konstantinovna, Vladimir Nikolaevich Binhi, and Anatolii Alekseevich Petrukovich. “Magnetic factor in solar-terrestrial relations and its impact on the human body: physical problems and prospects for research.” Physics-Uspekhi 59, no. 5 (2016): 502.
37. Breus, T. K., Baevskii, R. M. & Chernikova, A. G. Effects of geomagnetic disturbances on humans functional state in space flight. (2012).
38. Gurfinkel, Yu I., A. L. Vasin, R. Yu Pishchalnikov, R. M. Sarimov, M. L. Sasonko, and T. A. Matveeva. “Geomagnetic storm under laboratory conditions: randomized experiment.” International journal of biometeorology 62, no. 4 (2018): 501-512.
39. Krylov, Viacheslav V. “Biological effects related to geomagnetic activity and possible mechanisms.” Bioelectromagnetics 38, no. 7 (2017): 497-510.
40. McCraty, Rollin, Mike Atkinson, Viktor Stolc, Abdullah A. Alabdulgader, Alfonsas Vainoras, and Minvydas Ragulskis. “Synchronization of human autonomic nervous system rhythms with geomagnetic activity in human subjects.” International journal of environmental research and public health 14, no. 7 (2017): 770.
41. Alabdulgader, Abdullah, Rollin McCraty, Michael Atkinson, York Dobyns, Alfonsas Vainoras, Minvydas Ragulskis, and Viktor Stolc. “Long-term study of heart rate variability responses to changes in the solar and geomagnetic environment.” Scientific reports 8, no. 1 (2018): 1-14.
42. Azcárate, T., B. Mendoza, and J. R. Levi. “Influence of geomagnetic activity and atmospheric pressure on human arterial pressure during the solar cycle 24.” Advances in Space Research 58, no. 10 (2016): 2116-2125.
43. Dimitrova, Sv, I. Stoilova, and I. Cholakov. “Influence of local geomagnetic storms on arterial blood pressure.” Bioelectromagnetics: Journal of the Bioelectromagnetics Society, The Society for Physical Regulation in Biology and Medicine, The European Bioelectromagnetics Association 25, no. 6 (2004): 408-414.
44. Gmitrov, Juraj. “Geomagnetic disturbance worsen microcirculation impairing arterial baroreflex vascular regulatory mechanism.” Electromagnetic biology and medicine 24, no. 1 (2005): 31-37.
45. Zenchenko, T. A., S. Dimitrova, I. Stoilova, and T. K. Breus. “Individual responses of arterial pressure to geomagnetic activity in practically healthy subjects.” Klinicheskaia meditsina 87, no. 4 (2009): 18-24.
46. Vencloviene, Jone, Ruta Marija Babarskiene, and Deivydas Kiznys. “A possible association between space weather conditions and the risk of acute coronary syndrome in patients with diabetes and the metabolic syndrome.” International journal of biometeorology 61, no. 1 (2017): 159-167.
47. Pang, S.F., Li, L., Ayre, E.A., Pang, C.S., Lee, P.P., Xu, R.K., Chao, P.H., Yu, Z.H. and Shiu, S.Y., 1998: “Neuroendocrinology of melatonin in reproduction: recent developments”. J Chem Neuroanat 14(3-4): 157-166.
48. Viswanathan, M., Laitinen, J.T. and Saavedra, J.M., 1993: “Vascular melatonin receptors”. Biol Signals 2(4): 221-227.
49. Guardiola-Lemaitre, B., 1998: “Development of animal models for the chronobiotics of melatonin analogs”. Therapie 53(5): 439-444.
50. Bergiannaki, J-D., T. J. Paparrigopoulos, and Costas N. Stefanis. “Seasonal pattern of melatonin excretion in humans: relationship to daylength variation rate and geomagnetic field fluctuations.” Experientia 52, no. 3 (1996): 253-258.
51. Close, James. “Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?.” Proceedings of the Royal Society B: Biological Sciences 279, no. 1736 (2012): 2081-2090.
52. Rapoport, S. I., N. K. Malinovskaia, V. N. Oraevskii, F. I. Komarov, A. M. Nosovskii, and L. Vetterberg. “Effects of disturbances of natural magnetic field of the Earth on melatonin production in patients with coronary heart disease.” Klinicheskaia meditsina 75, no. 6 (1997): 24-26.
53. Rapoport, S. I., A. M. Shatalova, V. N. Oraevskiĭ, N. K. Malinovskaia, and L. Vetterberg. “Melatonin production in hypertonic patients during magnetic storms.” Terapevticheskii Arkhiv 73, no. 12 (2001): 29-33.