Wind-driven zonal jets in the South Pacific Ocean

Zonal jets west of the large islands of the South Pacific Ocean are predicted by theory, commonly seen in ocean models with sufficiently high resolution, and are beginning to be observed. These jets are often taken to reflect the blocking effect of the islands in the South Equatorial Current through "Island Rule'' dynamics. Here it is shown that quasi-permanent structures of the basin-wide wind field imply the existence of jets formed independently of the islands. Evidence for the existence of the wind-driven jets is found in climatological geostrophic currents. The hydrographic structures that produce the jets occur well below the thermocline.