Trade winds Fontaine Maury collected enough information to create wind and current charts for the world's oceans. As part of the Hadley cell, surface air flows toward the equator while the flow aloft is towards the poles. A low-pressure area of calm, light variable winds near the equator is known as the doldrums, near-equatorial trough, intertropical front, or the Intertropical Convergence Zone. When located within a monsoon region, this zone of low pressure and wind convergence is also known as the monsoon trough. Around 30° in both hemispheres, air begins to descend toward the surface in subtropical high-pressure belts known as subtropical
Asymmetry of the Intertropical Convergence Zone northern tropicalSST slightly. Vice versa, SST of southern part to the equator is much reduced. Therefore, SST of northern tropical is much higher, and higher than southern tropical, by which increases the CESG. As a result, this positive feedback, which is defined as Wind-Evaporation-SST (WES) will intensify this process. In this way, the WES keeps the ITCZ north of the equator. And the precondition of WES is the asymmetric distribution of SST, and WES also strengthens this process. According to the observation of equatorial upwelling and obvious asymmetry of the ITCZ in the Pacific and Atlantic, it is inferred that