Реферат: El Nino La Nina Essay Research Paper
El Nino La Nina Essay, Research Paper
As the easterly trade winds decrease, the western Pacific’s warm water flows toward the Americas. This giant mass of warm water flows over the colder water of the eastern Pacific. As this occurs, we get what is called El Nino, or the child. Its name (”the child”) is derived from its arrival during the Christmas season. Typical weather patterns of El Nino include an increase in surface temperatures as well as an increase in cloud cover over the equator. Also, for unknown reasons, a large high pressure system is formed over Australia while a low pressure system is formed over the central Pacific. Because winds move out of a high and into a low, the clouds that were formed over the Equator, are blown easterly towards the western seaboard. Also, the Jet Stream is altered so that it blows directly over the Atlantic Ocean, thus dramatically decreasing hurricanes for that year.
But when the warm waters brought on by El Nino recede, the cold waters of the Pacific Ocean move eastward and bring with it La Nina, the little girl. La Nina has a variety of different names such as El Viejo, anti-El Nino or simply “cold event”. When the warmer Pacific water is pushed westward by the trade winds, that water flows toward Asia and makes room for the colder, deep sea water, to rise and flow to the Americas. Because cold water doesn’t evaporate, there is a large reduction in the formation of storm clouds. The weather patterns of La Nina are basically an exact opposite of El Nino. Strong high pressure systems form over the Pacific and low pressure systems are discovered over Australia. Westerly trade winds push the warm waters west. The once thick cloud cover over the equator is split. Because of the opposite pressure systems, the Jet Stream is severely distorted and Atlantic storms gain strength, and numbers. Also, the hurricane season is more severe because of the Jet Stream alteration.
To compare El Nino and La Nina I made three different charts. Each one of the charts represents a different climatic change, temperature variation, rainfall and snowfall. The data was taken over a period of the three months of December, January, and February for the past two years. Also included in the charts are the daily and monthly normals (The “normal” was based on monthly records for the past 60 years). All the data was gathered from the NWS web site for the Albany Airport. Included with the charts is all the corresponding data.
From my charts I discovered many different and interesting things. One thing I found was that El Nino produced a truly a warmer than average winter. Also I discovered that La Nina was not necessarily a colder winter but a more extreme one (extreme meaning large variations of hot and cold temperatures). I also drew several conclusions from the snowfall data. One thing was that El Nino doesn’t have quite as much snow as a normal winter does. Unfortunately, by looking at La Nina’s data, the snowfall was very unpredictable and inconclusive. Surprisingly, the rainfall data was very different from the expected amounts. Since La Nina winters are colder, they are said not to have as much rain as normal, but in this case it had the most out of the three. Another surprise was that El Nino is a much warmer winter but it didn’t have the amounts of rain that La Nina did.
In conclusion, I believe that El Nino and La Nina both affect the Northeast’s climate. Although it doesn’t affect us as dramatically as on the West Coast, these two climatic phenomenons are very unpredictable and still can alter our seasons.