El Niño is a natural event that periodically weakens the
western surface of ocean currents in the equatorial pacific ocean. In an El Niño,
the wind that pushes water around (which keeps the east warm and west cold)
gets weaker making the ocean warmer, changing the air temperature and precipitation patterns in the United States.
The natural event that weakens the western surface ocean currents in the equatorial Pacific ocean is the <u>EL NINO EVENT</u>.
<u>Explanation:</u>
During this event, the easterly trade winds which converge which converge across the equatorial Pacific Ocean, weakens. Due to this reason the ocean current that draws the surface water away from the western coast of South America slows down. This results in precipitation in the southern part America while the northern part remains dry.