Which of the following causes El Nino over the Pacific Ocean?

Question

1)strong trade winds flowing west to east
2)buildup of warm water on the surface
3)jet stream bands shifting further south
4)upwelling of cold water from the deep

Answer 1

El Niño is primarily caused by the following factors from your list:

2. buildup of warm water on the surface - During an El Niño event, the typical warm water that accumulates in the western Pacific moves eastward, leading to a significant buildup of warm water in the central and eastern Pacific.

3. jet stream bands shifting further south - The change in ocean temperatures during El Niño affects atmospheric circulation, which can lead to a southward shift in the jet streams.

In contrast:

1. strong trade winds flowing west to east - This statement is incorrect when describing El Niño, as El Niño is typically characterized by weakened trade winds, which normally blow from east to west.

2. upwelling of cold water from the deep - Upwelling usually decreases during El Niño events due to the warmer surface waters, which can suppress the upwelling of colder, nutrient-rich waters.

In summary, the answers related to El Niño are 2 and 3.