Genre: Information/Explanation

Interactions between Earth's atmosphere and oceans drive weather and climate patterns . Although these interactions and patterns are complex , they are also predictable . This animation from The New Media Studio explains precipitation patterns by illustrating how differences in ocean surface temperatures create wind , and how wind patterns can in turn affect ocean surface temperatures . The Sun's energy is distributed unevenly across Earth's surface . Areas near our planet's equator absorb far more heat energy than areas near the poles . This uneven distribution of heat creates instability in Earth's atmosphere and oceans , and instability leads to movement of air and water . Air in the atmosphere is warmed by heat radiating from Earth's surface . The warmer the surface is , the warmer the air above it becomes . Because warm air is less dense than cold air , it tends to expand and rise , which lowers air pressure near the surface . Thus , regions of low air pressure generally form over warm water and land , while high-pressure regions form over cool surfaces . Such pressure differences create circular patterns of air called convection currents . In a convection current , warmer , low-pressure air rises and cooler , high-pressure air rushes in to fill the void . As the warm air rises , it loses heat in the upper atmosphere , cools , and sinks back toward Earth's surface , completing the circuit . The movement of air from high to low pressure in convection currents is responsible for most winds that blow across Earth's surface . The northern and southern hemispheres each have three zones in which winds blow predictably from east to west or west to east . On either side of the equator are zones dominated by the northeast and southeast trade winds , which blow strongly from east to west , and drive ocean currents in the same direction . The constant blowing of these strong winds pushes the warm surface water westward and causes a swell of warm water to build up in the western Pacific . In most years , the height of the sea surface near Indonesia is about 0.5 meters ( 1 . 6 feet ) higher than off the coast of Ecuador , and the water temperature is warmer by about 8 degrees Celsius ( 14 degrees Fahrenheit ) . On the east side of the ocean , cold water rises up from great depths to replace the water that was pushed westward . The interaction between global surface winds and ocean currents creates predictable climate patterns . For example , the heat carried westward by the warm ocean current causes powerful thunderstorms in northeastern Australia and eastern Indonesia . In contrast , the cold ocean surface on the east side of the Pacific gives rise to high pressure areas and low precipitation for much of the west coast of South America . About every three to four years , climate patterns in and around the Pacific Ocean change dramatically . The trade winds slacken and warm water that had been pushed to the west side of the Pacific is allowed to return eastward . This pattern , known as El Niño , typically causes droughts in Australia and Indonesia and damaging thunderstorms and floods in parts of South America and southern North America .