Winds of Change
The older you get the stronger the wind gets - and it's always in your face.
- Pablo Picasso
Look what the wind is bringing us!
by Lyall Watson
An atmosphere is the most vital prerequisite for life and mind. With it, everything becomes possible. Orbiting rockpiles organise themselves, taking on the self-contained look of living creatures, giving and receiving information, learning the essential skills involved in managing the sun.
Earth is such a creature. An organism in its own right, growing, wrapping itself in a moist and luminous membrane of air. And within this semi-transparent envelope, fed by a network of capillary breezes, carrying energy and information from one extremity to the other, are the great arteries of the prevailing winds.
The greatest gust of any wind in the world, outside of a tornado, seems to be 371 km/h recorded on April 12th 1934 at the peak of Mount Washington in the northern Appalachians. This took place during a gale that averaged over 200 km/h for that day and was boosted to its record speed by the funnel effects of the mountains around the weather station.
In 1938, during a gliding competition over the Rhï¿½n mountains in central Germany, five contestants flew into a thundercloud in search of lift. They were sucked directly into the violent centre and as their sailplanes broke up around them, all five parachuted free. "The consequences were dreadful. Instead of falling gently downwards, the parachutes were filled to bursting point by the wind and carried upwards. Higher and higher they soared into increasingly colder layers of cloud. However hard they tried to steer with their arms and legs, they could not escape the howling force of the gale. Huge raindrops soaked their bodies in a few seconds. Hailstorms lashed their faces. Only one man, severely injured, escaped with his life." It is difficult to imagine the ordeal of the others. At a height of over 10 km, they must have been frozen, tossed about like living icicles, stabbed at by lightning, until the storm grew tired of its game and discarded their bodies.
Even large aircraft fare little better. During WWII, a squadron of 8 fully laden bombers heading north from Australia flew into a line of cumulonimbus clouds. Only 2 came out the other side.
A full-fledged hurricane is a vast self-sustaining heat engine 100 times larger than a thunderstorm and 1,000 times more powerful than a tornado. An ordinary summer afternoon thunderstorm has the energy equivalent of 13 Nagasaki-type atomic bombs. Most hurricanes have at least 25,000 times that potential for destruction. One storm in 1928 dropped 2,500 million tons of water on Puerto Rico in just two hours, but this was in fact only a fraction of its total capacity. An average hurricane precipitates about 20,000 million tons of water a day, which represents the energy equivalent of half a million atom bombs.
There is, in warmer climates, less incentive to curl up with a good book. People in Florida and Louisiana buy and read fewer books than others of equivalent income in Oregon or Maine. And people everywhere show a preference for light fiction in the summer.
For a climate to be invigorating and lead to a high level of human arousal, temperature, pressure and humidity are not in themselves important. What is vital is that they change, often and at irregular intervals. Which, in principle, means that there needs to be frequent passage of a number of weather fronts, alternating highs and lows, bringing sharp fluctuations in local conditions and human physiology.
[This sounds much like "Windy Wellington!" I suppose I would call Wellington's climate "invigorating." I read in Chapman's book Strange Facts & True about New Zealand that Windy Wellington's nickname is well earned. On average, Wellington has 188 days with wind gusts of over 65 km/h and over 41 days when gusts reach 96.5 km/h.]
Gaia is a galactic creature, breathing cosmic air, and feeding on the fruits of the universe. The winds are her system of circulation, passing on energy and information, and we are one of the results. A recent flowering that gives her awareness both of the universe and of herself.
In 1953, two meteorologists finally proved that warm air lifts from Earth's surface in great buoyant bubbles, exactly like the vapour that rises from the bottom of a kettle of gently-boiling water. These bubbles or "thermal shells" are self-contained meteorological systems with their own internal turbulence. If they were visible, they would look like giant rotating smoke rings. And it is inside these that the larger birds with broad wings come to soar so effortlessly over land, that they seem, in the words of Keats, "to sleep wing-wide on the air." They are carried aloft as passengers inside parcels of air that rise faster than the birds' gliding flight causes them to fall, and never reach the bottom of such a bubble, because the air inside it is spinning fast enough to keep them flying horizontally.
This bubble-stream system of convection is clearly the most effective way of transporting heat upwards without too great a loss. Once they reach a certain height and size, the bubbles drift with the wind, redistributing warmth and, with it, the creatures held captive inside the temperature shell. Swallows have been seen soaring and feeding inside such bubbles at heights of up to 2,000 metres and can, in an average high altitude wind of around 50 km/h, be carried 1,000 km in a single day.
The air is alive with news. Each breath of wind carries tales of fruit and flower, of moose and moth in search of mates, of old dust, new rain and the constant ebb and flow of busy genes. The chances are that one of the viruses or bacteria you inhaled today is already looking for ways of fomenting revolution, spreading the message, and carrying on its craft of social and genetic engineering.
Even the trees, it seems, are listening.
Botanists working in woods near Seattle have just discovered that willows and alders warn each other when they are being attacked by leaf-eating insects. The natural defence of these plants to attacks by tent caterpillars or webworm is to produce alkaloids in their leaves that make them unpalatable. And when a tree is infected it sends out an airborne warning cry in the form of a chemical, probably one of the terpenes, that starts other trees some distance away preparing to meet the onslaught. Sugar maple and poplar saplings do something similar when mechanically damaged by having their leaves plucked or torn.
[Also see Don't Wilt Have a Pill for more on that same subject.]
A fresh breeze can be exhilarating, clearing the air, blowing sometimes, it seems, clean through us, carrying away obstructions that lie in the way of perfect freedom of mind. But anything more than a strong breeze becomes annoying, swirling up dust that irritates the membranes of nose and throat, causing acute discomfort to the eyes. We have a surprisingly low threshold to wind - almost as though at a certain speed, the skin begins to transmit warning signals to the brain, making us feel uneasy, perhaps a little anxious and irritable.
We, and apparently everything else larger and heavier than a dandelion seed, react to wind pressure in much the same way as sailing ships. At force 2, we first become aware of the movement of air across the skin as it, in effect, begins to fill our sails. At forces 3 and 4, gentle and moderate breezes tend to tilt things a little, keeping twigs and leaves in motion, raising dust and consciousness of the presence of wind about us. At force 5, simple tasks such as opening an umbrella, become quite complex. And suddenly, at the upper limit of force 6, we seem to run headlong into a real threshold.
When wind speeds reach about 45 km/h, we and porcupines and pedigreed cows all begin to run into the same pressure problems as sailing vessels, and may find it necessary to reef in a little, perhaps even tie down.
The threshold between forces 6 and 7 is very real, marking the point at which humans begin to struggle, whole trees start to sway, loose plant material becomes airborne, and small perching birds and insects get grounded.
The Biological Wind Threshold lies at the point where the Weather Bureau finds it necessary to issue its first "small craft warning". This is not an arbitrary point. It corresponds to a rise in turbulence which is not a linear function of wind speed, but shows a marked stepwise increase in intensity. This occurs at a wind speed of about 10 metres per second (36 km/h), which is the velocity at which a wind begins to exert a pressure equivalent to force 6. The result is that any force greater than 6 becomes universally relevant, and the "small craft warning" gets broadcast even on our own internal nervous network. The "gale warning" not only keeps shipping in the harbour, but also effectively keeps all birds and insects out of the air and all prudent humans indoors. But by the time "storm warnings" become appropriate, at wind forces greater than 11, the scale loses biological relevance. Such conditions are rare on land and, when they do occur, lead to general organic and inorganic devastation.
Confronted with a wind above the threshold between force 6 and 7, men tend to face into it, leaning against the pressure, head tilted up, often squinting and grimacing, seeming almost to take a wry pleasure in accepting the challenge as a test of strength. Women, even when similarly dressed in jeans and sweaters, behave differently. Most tend to turn away from the wind, head down, with arms folded protectively across the breast.
Lower limits to cold are imposed by our inability to produce enough heat in some circumstances, no matter how hard the body works. Hands are always some 8ï¿½C and feet 10ï¿½C cooler than the body core, and when either of these extremities reach zero, the tissues freeze, blacken and die. Unconsciousness occurs when the whole body temperature falls to 30ï¿½C and the heart stops altogether at 26ï¿½C. A naked body dropped into freezing water reaches this point in less than five minutes.
A normal healthy adult human, awake but at rest, produces about 50 kilogram calories per hour per square metre of body surface. For convenience, this quantity of heat is called "one metabolic unit" and is described as basal metabolism. To be comfortable, even in still air, in a room at 21ï¿½C with a humidity of 50%, such a person would need to be insulated. These particular conditions were selected in 1941, because it was discovered that they were the ones at which a man wearing the standard three-piece business suit of the day could maintain a constant skin temperature. The degree of warmth represented by that old-fashioned western suit and its underwear has now become the standard unit of insulation in the international clothing industry and is known everywhere as one Clo.
For comparison, a bikini represents a Clo value of .04, a pair of shorts .1, jeans and a T-shirt .33, a warm skirt and blouse over a slip total .45, and a light modern suit about .7. Add about .3 Clo for knee boots, .37 for a V-neck sweater, and a further .7 Clo for a complete set of thermal underwear. It takes four layers of clothing, including a greatcoat, gloves, hat and earmuffs, to bring the Clo value up to 3.0, and a down-lined polar suit to reach 3.5, and yet both still fall short of the 4.1 Clo routinely worn by any husky dog. Which begins to make sense of the old trapper's rating of winter weather into "one, two, or three-dog night." The average polar bear, incidentally, wouldn't be seen alive or dead in a coat of less than 8.0 Clo.
[This lovely book included these words about windows (the real kind, not the operating system from Microsoft):]
The eyes of a house are not just for looking through, and were never meant to be sealed shut. These are the time-honoured rules:
The "Venturi Effect" is a blast that develops in the gap between two buildings, which can involve wind forces three times greater than those in the open, and many times higher than those in sheltered streets nearby.
It is always unpleasant, can be dangerous, and seems best voided by the old-fashioned solution of building around plazas or squares that enjoy the wind shadows created by their own "Cell Effect."
[The Telecom building edging the southern boundary of Chaffers Marina (where our boat is moored in Wellington), also known as the Herd Street Post Office and the subject of a heritage debate, has a pronounced "Venturi Effect."]
To a very real extent, a city behaves like an organism in its own microclimate. The roughness of the skyline reduces the speed of winds passing over it, but increases their turbulence, channelling eddies and flows, sometimes at high speeds, through the concrete canyons. When winds are light, the irregularity of heat flow inside the city creates its own wind field. It has been suggested that if the surface air motions in a city were to be recorded from above with time-lapse photography, the patterns would resemble the motions of "an amorphous, slowly pulsating jellyfish"
The precise nature of the connection between earth's magnetic field and the wind remains a mystery, but an answer could lie in the oceans. Sea water is a good conductor and the huge rivers of salt water carried along by ocean currents cut across our field, inducing a weak electric current that charges the entire planet, turning the world into a giant dynamo.
A strong magnetic field produces fast ocean currents which spread heat in the ocean sink more evenly, cutting down the disparity between hot and cold zones of water and air, and eliminating some of the winds which normally rush to restore equilibrium. But the process of course goes on. Calm warm weather results in a slowing down of ocean currents, producing a weaker field, uneven distribution of heat, more frequent winds and therefore cooler weather.
The result is an elegant feedback system in which temperature, rainfall, ocean currents and electromagnetic fields are all held in delicate equilibrium on the responsive see-saw of world wind.
Niva [in Sanskrit] means "to stop blowing", and nirvana "to be extinguished altogether".
The wind produces some of its most memorable effects once it reaches force 6, the beginning of a gale, and strums telephone and power lines like the strings on a giant guitar. When the evoked tone coincides with the natural harmonic of the wire, then the volume increases and holds its pitch in an eerie concert. If this moves into a minor key, it has the ability to produce physiological changes, lowering the blood pressure of anyone nearby. Wires strung between poles whose interval is appropriate for major key tones, have the opposite effect.
Sailors and fishermen, people who live constantly in the wind, become habituated. Their bodies learn to deal with wind stress. But many city dwellers lose the ability to adapt.
At the Hebrew University in Jerusalem, pharmacologist Felix Sulman has been studying the physiological responses to Israel's version of the sirocco. He finds that almost 1/3 of the population experience some kind of adverse reaction to the sharav. And of these, 43% show an unusually high concentration of serotonin in their urine. This is a powerful and versatile hormone which causes the constriction of peripheral blood vessels, including those in the brain, controls sleep, and is responsible for the development of mood. It is a natural tranquilliser, but too much of it produces clinical symptoms which include migraines, allergic reactions, flushes, palpitation, irritability, sleeplessness and nausea.
The Santa Ana, like other ill winds, is perfectly capable of violence without human help. When it blows, there is the usual increase in ulcer perforation, embolism, thrombosis, hï¿½morrhage, myocardial infarction and migraine - not to mention theatrical failures, lower industrial production and loss of milk in cows. All these disorders are the result of tension, the product of an atmosphere heavy with menace and imminent catastrophe. Of dry air so filled with static electricity that even a handshake becomes shocking.
Nathan Robinson, at the Israel Institute of Technology in Haifa, finds that there is a noticeable increase in the number of positive ions in air, starting 12 hours before a sharav arrives, and reaching concentrations of over 5000 ions per cubic centimetre when the wind is at its peak.
Sulman in Jerusalem sees this as the missing link between winds and their ills. The positive ions are mostly molecules of oxygen which, he suggests, are inhaled and bind even more readily than uncharged oxygen to red blood corpuscles in the lungs. This lowers partial oxygen pressure in the alveoli and allows carbon dioxide pressure to increase. People breathing positive ions certainly do begin to pant and struggle for breath and this, concludes Sulman, is what releases the stress hormone serotonin, with all its characteristic symptoms.
Source: the wonderful book Heaven's Breath: A Natural History of the Wind by Lyall Watson. Watson obviously lovingly respects the earth. (I'll bet he recycles everything he can.)
For pages on natural disasters - including lightning strikes, volcanoes, floods, global warming and more - as well as satellite photos and some great pictures of trees,
clicking the "Up" button immediately below takes you to the Table of Contents page for this Environment section.