Wind is a concept that has its etymological root in the Latin language: ventus. It is the current of air generated in the atmosphere for reasons of nature.
According to their characteristics, it is possible to classify the winds in different ways. The trade winds are those that blow between the tropics. These winds depart from subtropical areas of high pressure towards equatorial regions of low pressure: due to the rotation of the planet, the trade winds are deflected westward by the Coriolis effect. It is known as the Coriolis effect, which can be seen in a rotating frame of reference when a body is in motion. In turn, a frame or frame of reference is a set of conventions that observers use to be able to measure certain amounts of physics, such as position.
Thus, in the southern hemisphere, the trade winds blow from the southeast to the northwest, while in the northern hemisphere they are directed from the northeast to the southwest. The trade winds drive what is known as the Hadley circulation, which involves a transfer of heat from the equatorial region to the subtropical region. The circulation or Hadley cell is a fluid mass dynamically organized to respond to a change in temperature, in a closed circuit of the Earth’s atmosphere that predominates in tropical and equatorial latitudes. As for the location, they can be seen at latitudes of 30º from the equator, both in the northern and southern hemispheres. Then, an upward cellular movement carries the heat with the air and takes it to higher latitudes. The meeting between the trade winds of the southern hemisphere and the trade winds of the northern hemisphere creates the so-called intertropical convergence zone, better known by the acronym ITCZ. The ITCZ can be defined as the convergence of moist and warm air masses, giving rise to a low pressure belt in the equator region. In the ITCZ it is normal for storms to form. It is important to note that solar heating of the atmosphere is the fundamental energy source for this convergence. As atmospheric air is diathermic, that is, it does not heat up when the sun’s rays pass through it, the increase in temperature occurs indirectly, only when it touches the continents and oceans and receives part of their heat. At that moment, in addition to heating, the air goes through a state of expansion and loses density, which is why convection occurs, a phenomenon that consists of reaching the upper atmosphere.
In antiquity, the trade winds were instrumental in travel from Europe to America. When those winds weren’t blowing hard, sailboats couldn’t move forward. Therefore, the periods when the trade winds lacked intensity were dangerous for this type of expedition that aspired to reach American soil. In this sense, it is important to highlight that the intensity of the trade winds depends on the time of year; If we add to this the fact that they are not aggressive and destructive winds, it is understandable that for long periods of time they seem rather languid. As for the etymology of the word alisios, we can point out that it is formed from the Latin root alis; was used throughout the 13th century in the French language to denote the gentle, amiable, measured, and gentle nature of these winds, which appear regularly and do not blow violently.