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How does a subtropical gyre help power the Gulf Stream?

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Map of the North Atlantic Ocean showing major ocean currents, with warm currents like the Gulf Stream and North Atlantic Drift highlighted in pink and cold currents in blue. Arrows indicate current directions and relative speeds, connecting the eastern coasts of North America, the western coasts of Europe and Africa, and the Arctic region. — Gulf Stream Major warm and cold currents of the North Atlantic Ocean.

The subtropical gyre acts as the central hub of energy for the Gulf Stream by creating a large-scale, wind-driven circulation system. This process is powered primarily by the climatological wind distribution, specifically the clockwise circulation of a subtropical anticyclone.1

The mechanism functions through the following steps:

Ekman Transport: Wind stress on the ocean surface causes Ekman transport, which moves surface water at an angle to the wind. Within the subtropical gyre, this transport leads to a convergence of surface waters.234
Sea Level Elevation: This convergence forces less dense, warm surface water to accumulate, creating a "hill" in sea level that can be about one metre higher than the surrounding ocean.123
Geostrophic Current: The resulting horizontal pressure gradient, balanced by the Coriolis force, generates a geostrophic current. This dynamic force drives the intense, poleward-flowing western boundary current known as the Gulf Stream.124

Essentially, the gyre’s energy is stored in this elevated lens of water, which maintains the pressure gradient necessary to sustain the Gulf Stream's powerful flow.1