A relatively new type of climate anomaly El Niño heat to the center, shifted from the east to the central part of the Pacific Ocean, it is becoming more frequent and more powerful — it can "messed things up" climate scientists engaged in long-term modeling, says the joint study of the Jet Propulsion Laboratory (JPL ), NASA and the National Oceanic and Atmospheric Administration of the United States (NOAA).
El Niño is Spanish for "little one" or "boy", — climatic anomaly in the equatorial Pacific, where the abnormally warm surface water moves along the equator to the American continents. Cold "contrast" El Niño is called La Niña, "babe" or "girl." These phenomena are periodically replace each other, exerting a significant influence on the climate of the planet.
Tong Li (Tong Lee) from JPL and MakFeyden Michael (Michael McPhaden) of NOAA estimated fluctuation strength of El Niño in the period since 1982, according to satellite observations and direct measurements of water temperature in the Pacific Ocean, which carries NOAA. They found that during this period the power anomalies, defined as the amount of sea surface temperature deviations from the average, almost doubled, reaching a peak in 2009-2010. The results of the researchers in a paper published in the journal Geophysical Research Letters.
"Our research has led us to the conclusion that the long-term trend of growth temperatures, which we observe in the central Pacific Ocean, mainly due to a strong El Niño, and not the general increase in the temperature of the environment" — said Lee, whose words Press Service of JPL.
Scientists believe that stronger anomalies can explain the steady increase in temperatures in the Pacific region, which is observed in the last few decades. According MakFeydena, it is possible that in this way has an effect of climate change on El Niño. His colleague said that in order to ascertain the causes of the anomaly change — natural variability or climate change caused by human activity — will require additional research.
"Classic" El Niño, the authors explain the work, acting on a specific scenario: the usually strong trade winds from the east in the eastern tropical Pacific Ocean become weak, and this prevents the mixing of cold and warm waters — the latter begins to move in the direction of North and South America. Because of this, on the surface of the ocean there is unusually warm area, the center of which is to the east.
In the early 1990s, however, the anomaly was often "retreat" from the script: the new type of El Niño, called, in particular, the Central Pacific, or "El Niño Modoc» (modoki is Japanese for "similar, but the other "), the maximum temperature is shifted from the east to the center. These anomalies were observed in 1991-1992, 1994-1995, 2002-2003, 2004-2005 and 2009-2010. Many climate models indicate that global warming scenarios for this type of anomaly will occur much more frequently, the report said.
"If the trend we are seeing continues, it will insert a spanner in the long-term weather and climate forecasting, which is largely based on our understanding of El Niño as they were in the second half of the XX century", — concluded MakFeyden.