Planetary vorticity results in deflection of ocean currents and winds through th
ID: 295269 • Letter: P
Question
Planetary vorticity results in deflection of ocean currents and winds through the so-called ‘Coriolis effect’ in the northern and southern hemispheres. Given what you have learned about planetary vorticity, explain why the Equatorial Undercurrent is such an unusual ocean current in that it flows in a dead straight line across the entire width of the Pacific Ocean at a depths typically around a couple of hundred metres beneath the surface? Also predict which direction the Equatorial Undercurrent must flow, west to east OR east to east? (this is a clue!)
Explanation / Answer
Equatorial undercurrents move from west to east. It is located within the band of 20 N around the equator. It is a wellknown fact that Coriolis force is not present along the equatorial belt. So, there is no deflection associated with this undercurrent. Two western boundary current merges and form this undercurrent, asymmetric with respect to the equator.