What is the primary origin of trade winds?

The primary origin of trade winds can be attributed to the pressure belts located at approximately 30° N and S latitudes. These winds are part of the larger global circulation system, specifically the Hadley cell, where warm air rises near the equator, creating a low-pressure area. As this air rises, it cools and moves towards the poles, eventually descending at around 30° latitude, where it creates high-pressure zones.

The descending air warms up as it compresses, leading to high-pressure areas that influence the wind direction. The trade winds, therefore, flow from these high-pressure areas toward the low-pressure region near the equator. This movement completes the cycle of air circulation and is what drives the consistent easterly winds known as trade winds.

While land heating differences, equatorial high-pressure regions, and ocean currents play significant roles in overall atmospheric circulation, they do not primarily dictate the formation of trade winds. The main drivers remain the large-scale pressure belts at around 30° N and S, making them the correct answer in this context.