If trade winds die down or reverse, there is a possibility of a hurricane and an ENSO event. Such a change can be explained by the nature of trade winds and their characteristics. Trade winds are the groups of dependable surface winds that appear between the sectors of rising and descending air. Out of them, the most persistent ones are easterlies, the winds centered at approximately 15°N and 15°S latitudes. These winds are the “surface winds of the Hadley cells” that migrate from the horse latitudes to the doldrums.
The El Niño Southern Oscillation (ENSO) is closely associated with trading winds. ENSO illustrates two significant issues pertaining to ocean circulations. The first point is that ocean circulations collaborate with the atmosphere. The second issue is that the circulations of oceans can have crucial effects on global weather. ENSO is composed of two cycles: El Niño and La Niña. The El Niño cycle starts when the Pacific Ocean’s western tropical water moves eastward along the equator in the direction of the South America coast. Under usual circumstances, this warm water pools near the Philippines and Indonesia. However, during El Niño, the warmest surface waters of the Pacific “sit offshore” of northwestern South America.
El Niño is officially estimated when rainfall from storms and ocean temperatures veer to the east simultaneously. Additionally, forecasters pay attention to prevailing trade winds that die down or reverse. The reason for such observations’ significance is that they set up a “feedback loop” between the ocean and the atmosphere. Such a loop can advance El Niño conditions. During the El Niño, the location of tropical storms moves in the eastern direction due to atmospheric moisture serving as fuel for thunderstorms. More than that, the biggest amount of evaporation occurs above the warmest waters in the ocean.
Taking into consideration the mentioned facts, it is relevant to assume that the character of trade winds has a significant impact on the ocean-atmosphere. Thus, it can also be estimated that the number of hurricanes would grow in case trade winds die down or reverse. There is one more phenomenon that plays a crucial role in this respect. This cycle is opposite to El Niño, and it is called La Niña. La Niña is recorded when trade winds blow with more strengths than they normally do and when waters of the tropical eastern Pacific have a lower temperature than usual.
While scientists have learned to identify ENSO and sometimes even predict it, they admit that there is no unanimous understanding of the causes of the El Niño cycle. El Niños are quite dissimilar sometimes. Also, the ocean and the atmosphere do not always adhere to the same patterns during different El Niños. Oceanographers remark that there is no single major cause of El Niño. Because of this, it is impossible to arrange a perfect forecasting method. There is only a moderate level of predictability, which means that cycles are not the same every time. Therefore, the character of trade winds, which play an important role in the circulation of the atmosphere, can be used to predict hurricanes and ENSO events.