Question

which is expected to happen during la niña?
a. there is unusually low air pressure over the western tropical pacific.
b. the trade winds weaken as the pressure gradient increases.
c. unusually warm ocean temperatures are recorded in the equatorial pacific
d. upwelling along the west coast of south america increases.

Explanation:

During La Niña, trade - winds strengthen, leading to increased upwelling along the west coast of South America. This is because stronger trade - winds push surface water away from the coast, allowing cold, nutrient - rich water from the deep to rise. In the western tropical Pacific, there is high air pressure. The trade - winds strengthen as the pressure gradient increases, and ocean temperatures in the equatorial Pacific are unusually cold.

Answer:

D. Upwelling along the west coast of South America increases.