Last week, I put forward the seemingly outlandish proposal of several scientists that our COVID-19 pandemic might actually have something to do with solar activity. The only way to consider this as any sort of remote possibility is to take a deep dive into how profoundly all life on Earth is affected by what our 93-million mile away neighbor is up to.

American essayist Joan Didion once wrote about the Santa Ana wind of Southern California “drying the hills and the nerves to flashpoint.” Travel writer Peter Mayle warned of an increase in lunatic behavior among the inhabitants of Provence during the season of Le Mistral.
These are two of the many so-called ‘winds of ill-repute’—special seasonal high winds which are supposed to acutely affect human behavior and health.
During the seasons of the winds, inhabitants complain of insomnia, migraine attacks, nausea and vomiting, anxiety and tension—even diminished or dimness of vision.
Tempers flare, nerves are frayed, hospital admissions swell, suicide numbers skyrocket. Even the psychiatric wards are fuller than usual.
Surgeons put off carrying out surgery because the blood clots more slowly. Judges have been known to deal more leniently with crimes of passion if committed when the winds blow.
For many people, a wind of ill repute is the weather of apocalypse. “One woke in the night troubled not only by the peacocks screaming in the olive trees but by the eerie absence of surf,” wrote Didion about the Santa Ana. “The sky had a yellow cast, the kind of light sometimes called ‘earthquake weather’.”
All the ill winds have common elements: a rapid rise in temperature, an abrupt decrease in humidity and, most significant of all, a sharp rise in the level of positive ions released into the air.
Researchers who have studied the Sharav discovered that  half a day to three days before the winds began to blow, the total number of atmospheric ions nearly doubles, and the ratio of positive to negative ions changes from 1 to 2 to 1 to more than 3. The change in the air’s ionic charge has a direct relationship to the onset of illnesses felt by the populations a day or two before the arrival of the winds.
Ions are simply electrical charges in the atmosphere—an atom with too many or too few electrons. An ion is formed when a molecule encounters enough energy to unleash an electron from it, from other sources but also the explosive and unpredictable activity of the sun, particularly relating to the level of cosmic rays.
The atom that loses an electron becomes a positive ion, and the molecule the ejected electron attaches itself to becomes a negative ion.
Both positive and negative ions are equivalent to a tiny pulse of static electricity, and the air we breathe is made up of billions of these tiny charges.
Good ‘clean’ air contains 1500–4000 ions per cubic centimeter and the preferred ratio should be slightly more negative than positive ions—1.2 to 1.
However, ions are highly unstable and, in our industrialized and largely indoor lives filled with pollution and electromagnetic charges from artificial sources, the number of ions we usually breathe in is drastically diminished and the ratio often disturbed, leaving most of us inhaling a low level of mainly positive ions, which aren’t particularly good for us.
The question of whether these miniscule charges in the air affect living things fascinated the late Professor Albert P. Krueger, Emeritus Professor of Bacteriology at the University of California. For more than 25 years, Krueger studied these effects at the specially created Air Ion Laboratory, within the Life Sciences department of the university. His work resulted in more than 75 published papers, which transformed this field from a curiosity of nature to a respectable scientific discipline.
Krueger’s work showed that both positive and negative ions can have a major effect on the health of living things. High levels of either, for instance, are lethal to bacteria. Krueger also showed that changing the level of ions produces substantial changes in many animal activities, such as their growth rates, sleeping periods and rates of respiration—even their output of urine or feces.
Even plants are profoundly affected by ions. Krueger’s studies showed that a high density of negative ions could speed up plant growth by as much as 50 per cent. High levels of ions stimulated the metabolism of certain enzymes, nucleic acid and uptake of oxygen—all of which would markedly increase growth.
Krueger was arguably the first to demonstrate that negative ions are good for you. His experiments revealed that changing the ion ratio in favor of negative ions is highly beneficial to all living things and can boost the healing of burns as well as healthy cell proliferation and regeneration.
The exact mechanism that causes air ions to have such a profound effect eluded Krueger until he made a remarkable discovery: the relationship between levels of these charges in the atmosphere, and the manufacture of the brain and blood hormone serotonin.
First with laboratory animals and then in humans, Krueger found that ions in the air affected the production and oxidation of serotonin in the blood and brain in mammals. High levels of positive ions dramatically raised blood levels of serotonin whereas negative ions decreased them.
Serotonin, produced by the pineal gland, exerts profound effects on the endocrine and neurovascular systems, and also helps to control metabolism and such activities as blood-clotting, blood pressure and smooth-muscle contraction.
In the brain, serotonin controls the sleep–wake cycle, hunger and temperature regulation, but also mood and emotions. However, too much serotonin makes you feel ill and give you headaches; low levels make you feel drowsy and depressed.
Professor Felix G. Sulman, a pharmacologist at the University of Shibolai in Jerusalem, also studied the effects of these winds on the production of serotonin and found that in people prone to the effects of the ill winds, levels of serotonin rose sharply two days before the onset of the Sharav in Israel. The levels remained high and only leveled off after the winds finally diminished.
So what’s the connection between solar activity and the level of ions in the air?  Several years ago a joint team of scientists from the National Space Institute at the Technical University of Denmark (DTU Space) and the Hebrew University of Jerusalem made the link between solar activity and changes in the cloud cover of the Earth.
The more solar activity, they discovered, the more the Earth is protected from cosmic rays and the less the cloud cover. The less the solar activity, the more cosmic rays and the higher number of clouds.
Clouds are large concentrations of ions (and lots of positive ions in polluted areas). The sun is unusually quiet this year, with less activity, meaning we have more unshielded cosmic rays and so an increase in ions. And high levels of ions, as we know, affect human physiology and behavior.
Does this prove that the sun caused COVID-19? Short answer: no.  But until we recognize that we are, essentially, an intergalactic superorganism, we will never be able to fully understand health issues like pandemics – much less ourselves.