Question

multiple choice question
the southern oscillation is the ______.
change in upwelling that occurs along the coast of peru during el niño events
process cyclones undergo as they move from the southern hemisphere to the northern hemisphere
periodic reversal of high - and low - pressure systems on either side of the tropical pacific ocean

Explanation:

The Southern Oscillation is characterized by the periodic reversal of high - and low - pressure systems across the tropical Pacific Ocean. It is not related to the change in upwelling during El Niño in Peru (which is a consequence of El Niño - Southern Oscillation), nor is it about the movement of cyclones between hemispheres.

Answer:

O periodic reversal of high- and low-pressure systems on either side of the tropical Pacific Ocean