What are some of the causes and effects of El Nino?

Can someone please explain the causes and effects of el nino and la nina?

• it is interesting how el nino an la nina have the opposite effects, but i am really confused as to how they are causes. I would really appreciate if someone can give a detailed account on how both are caused and a few effects from both,. Thank you.

• Answer:

  hi Miss D Fied no more Ocean currents swirl around between continents because, One of the forces that propel the water is; Cold north and south polar regions Hot equatorial sun Hot water expands and rises, cold down It is propelled by the sun in the same way as the Wind currents Example , fill you bath tub with cold water put a heat source on top of one end , Put some thing like coffee beans, that just barely float in the water and something that just barely sinks. Watch for a minute or two and the particles will change ends as the hot water expands. Study wind currents also , they are easy to understand . Hot air rises. Hot day wind blows on shore as the morning sun heats the land and nearby air faster than the air over the water , which circulates the heat below and therefore the surface water is slow to heat up. Ever walked on the hot beach sand in your bare feet and ran to get to the cool water ? Then you get used to the water temperature and swim out into the deeper water and dive down in the afternoon and find there is a shallow area of water about one or two feet deep that it is warm and the temperature drops as you dive down. This is an example of the fluid dynamics of any liquid or gas that expands and contracts when heated and cooled. Are you still with me??? I am giving you the elements, not the exact answer in a phrase. The tools of understanding, not the answer as such. The next force propelling ocean currents on the complex geography of the earth, is the tidal waves that follow the Gravitational flow of the sun and moon at 1000 miles an hour. This is one or two 12,000 mile long waves up to one or two feet deep in mid ocean, that move westerly causing powerful currents around the tips of continents etc. that swirl and circulate . Often reversing direction as the high and low point of the wave passes by. Which is the surface speed of the earth as it rotates. 24,000 nautical miles per hour . 24 hours in a day, one hour the sun is 1,000 miles further along on its journey. We have quickly answered another question while we are in the neighbourhood . Where did the hour come from ! Meanwhile the wind is acting on the surface water and slowly pulling the water with it . Consequently the ocean currents often follow the trade winds. Back to Mr Nino and his wife , All these forces interact in the vast pacific to create the swirling currents you see on an ocean map . They are usually fairly predictable but climate change , alters the ocean temperatures and currents. The worlds biggest current is the humboldt current that circles around the large open water between Australasia and South America. When the surface temperatures alter from normal the current changes and when the current changes the surface temperature changes. Creating all the differences in sea life and land climate . This is what they call the el Nino or la Nina effect. North of the equator is a similar current called the North Atlantic Drift which usually circulates in the opposite direction , and has a direct influence on the west coast of North America.