Part 1 of Essay
Typically, the level of ocean water around the world is higher in the western Pacific and lower in the eastern, near the Western coast of South and North America. This is due primarily to the presence of easterly winds in the Pacific, which drag the surface water westward and raise the thermocline relatively all the way up ....

Part 2 of Essay
.... normal year, there is upwelling on the western South American coastline, and cold waters of the Pacific rise and push westward. However, during an El Nino year, upwelling is suppressed and as a result, the thermocline is lower than normal. Finally, thermocline rises in the west, making upwelling easier and water colder. Air pressures at sea level in the South Pacific seesaw back and forth between two distinct patterns. In the high index phase, also called "Southern Oscillation", pressure is higher near and to th ....