1 What happened in 1982 El Nino? Mehmet ILICAK RSMAS, University of Miami 2005 2 Outline What is El Nino? What is El Nino? Why 1982? Why 1982? Oceanographic Events Oceanographic Events Meteorological Events Meteorological Events Summary Summary 3 What is El Nino? major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean.Eastern Pacific OceanEastern Pacific Ocean Non-El Nino conditions the trade winds blow towards the west across the tropical Pacific. Non-El Nino conditions the trade winds blow towards the west across the tropical Pacific. During El Nino, the trade winds relax in the central and western Pacific leading to a depression of the thermocline in the eastern Pacific, and an elevation of the thermocline in the west. During El Nino, the trade winds relax in the central and western Pacific leading to a depression of the thermocline in the eastern Pacific, and an elevation of the thermocline in the west. 4 Why 1982 El Nino? The strongest and most devastating of the century. The strongest and most devastating of the century. 2,000 deaths. 2,000 deaths. $13 billion in damage to property and livelihoods. $13 billion in damage to property and livelihoods. 5 Oceanographic Events The Annual Cycle in the Tropical Pacific The Annual Cycle in the Tropical Pacific The Canonical El Nino The Canonical El Nino Theory Theory El Nino El Nino Oceanographic Events during El Nino, Mark A. Cane 6 7 Standard El Nino Phases Prelude: Strong easterlies, high sea level, Prelude: Strong easterlies, high sea level, deep thermocline. Onset: East trade winds begin to diminish Onset: East trade winds begin to diminish Event: Warming the South Coast of America, westerly winds, high sea level Event: Warming the South Coast of America, westerly winds, high sea level Mature Phase: Another warming in December, trade winds become normal Mature Phase: Another warming in December, trade winds become normal 8 9 Theory El Nino West coast sea level decreased in April and continued to drop throughout the year. West coast sea level decreased in April and continued to drop throughout the year. East Coast Islands sea level increased 25cm instead of 10cm. East Coast Islands sea level increased 25cm instead of 10cm. 11 SST Anomalies 12 Meteorological Aspects of El Nino In normal conditions, Walker Circulation In normal conditions, Walker Circulation 13 Typical El Nino vs El Nino Atm. Conditions after the peak of Typical El Nino 1982 El Nino Atm. Conditions 14 Possible reasons of 1982 El Nino Swing in the Southern Oscillation Swing in the Southern Oscillation El Chichon eruption El Chichon eruption The El Chichon eruption of 6th April 1982 was powerful enough to eject aerosols and dust particles into the stratosphere, resulting in greater scattering and reflection of incoming sunlight, thus dampening the warming effect of El Nio. The El Chichon eruption of 6th April 1982 was powerful enough to eject aerosols and dust particles into the stratosphere, resulting in greater scattering and reflection of incoming sunlight, thus dampening the warming effect of El Nio. 15 December 1982-February SST & SST Anomalies