Editing Downwelling (section)

=== Wind-driven Ekman transport ===
[[Ekman transport]] is the net mass transport of the ocean surface resulting from wind stress and the [[Coriolis force]]. As wind blows across the ocean surface, it causes a frictional force that drags the uppermost surface water along with it. Due to the Earth's rotation, these surface currents develop at 45° to the wind direction. However, compounding frictional forces cause the net transport across the [[Ekman layer]] to be 90° to the right of wind stress in the [[Northern Hemisphere]] and 90° to the left in the [[Southern Hemisphere]]. Ekman transport piles up water between the [[trade winds]] and [[westerlies]] in [[Ocean gyre|subtropical gyres]], or near the shore during coastal downwelling.<ref name="www.sciencedirect.com">{{Cite web |title=Ekman Transport - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/ekman-transport |access-date=2023-12-05 |website=www.sciencedirect.com}}</ref> The increased mass of surface water creates high-pressure zones that push water downward. It can also create long convergence zones during sustained winds to create [[Langmuir circulation]].