“So the whirlwind originates in the failure of an incipient hurricane to escape from its cloud: it is due to the resistance which generates the eddy, and it consists in the spiral which descends to the earth and drags with it the cloud which it cannot shake off. It moves things by its wind in the direction in which it is blowing in a straight line, and whirls round by its circular motion and forcibly snatches up whatever it meets.” (Meteorology, by Aristotle)
Aristotle was famous for his writings on philosophy and logic, along with psychological, physical and natural history works. What he was not well known for was his views on meteorological points, in particular his writings on the wind. Even though his ideas were not considered accurate according to today’s standards, his written treatise, “Meteorologica (The Study of Weather),” is the earliest documented work on weather phenomena in the field of science.
The force of the wind
Wind is a vital force of weather changes. High and low pressures cause the wind to occur, with varying differences causing different wind speeds. Because air at the Equator is warmer than at the poles, warm air naturally rises toward the cooler air in the north. When this happens, the surrounding cool air will begin to flow inward,replacing the rising warm air that is losing density. Like an invisible bubble in the atmosphere, the warm air will cause a drop in air pressure, attempting to control the pressure differential. This process is a result of unequal heating of various surfaces on Earth.
A major part of wind movement is air pressure, also known as atmospheric pressure-referred to the weight of the Earth’s atmosphere as it presses down on the surface of Earth. Variations in air pressure cause weather changes and wind. High-pressure areas naturally seeking low-pressure areas, developing and influencing the wind. Wind speeds are also influenced by pressure gradient, These are the differences in atmospheric pressure on various points of the Earth’s surface.
Because sunlight and the sun’s rays carry energy, the sun is the driving force behind the weather and climate on Earth. The total energy of any surface on Earth is equal to the total energy it returns to space. Facts include the average temperature is required to be steady, and the surface of Earth is heated during the daytime only. However, the energy radiates back both day and night.
The flow of energy is influenced by the atmosphere, due to the shape of the planet and the direction of the sun’s rays—targeting the equator first and the Polar Regions last. As stated, warm air will naturally move toward cold air, which in turn develops the wind. Because air is able to flow in order to carry heat from one place to another, weather is produced with warm air lighter than cold air. In other words, rising air expands and the expansion of gas in air begins to cool it down, causing air movement.
Changing air pressures
Today, science has discovered that wind, high and low pressures, pressure gradients and contrasting temperatures on Earth are part of a big picture, working naturally to correct changes in air pressure and temperatures as the air rises above sea level.
Studies have shown that air is a gas that responds to latitude, temperature and elevation-due to the slightly oval shape of the Earth. This is best demonstrated through commercial airlines. Passengers who air-travel are told of their estimated time of arrival (ETA) and the height at which they will be flying—none of which is said to be true. This is because of the various changes in weather systems, elevation and temperature. What they should be told is they are flying is at a constant air pressure, not at a constant altitude.
Wind is generated from light spring breezes into massive hurricanes and tornadoes. They originate from the flow of high-density areas into low-density areas until they equal out. This is similar to the homeostatic control mechanisms in people, which works to prevent imbalances from occurring in the body.
Weather differences are the result of several things—pressure difference, contrasts in temperature, or even a difference in water vapor. These differences can be caused by a multitude of things that involves the density amounts of two bodies of air. Some causes would be a high-density cold air mass, water evaporation of a body of water, sunlight or the earth’s rotation.
How pressure differences create wind is a highly complex situation, with each variable dependent on one another. But one thing for sure…without the movement of conflicting air masses and temperatures…wind would become totally non-existent.