An El Nino is fully in place when:

Question

Quizplus · Accepted Answer

The leading edge of the Kelvin wave is what triggers the full onset of an El Nino, and it reaches the western coast of South America first. Option A is incorrect because dispersing water spreading away from the equator on the eastern coast of South America is related to La Nina conditions. Option B is also incorrect because dispersing water spreading away from the equator on the western coast of South America is not specific enough to indicate the onset of an El Nino. Option D is incorrect because the leading edge of the Kelvin wave does not reach the eastern coast of South America first.

An El Nino Is Fully in Place When