Its atmospheric component is defined by the pressure difference between Tahiti and Darwin, Australia, and is measured by the Southern Oscillation Index.
An instance of this effect is credited by some historians as setting off the famines that energized the French Revolution, while another is tied to the demise of the Moche civilization. Both the Atlantic and Pacific oceans see a lower incidence of tropical cyclones during an instance of this, and 1998 contained an especially intense instance of this phenomenon, helping lead to that year being the warmest on record. Its atmospheric component is defined by the pressure difference between Tahiti and Darwin, Australia, and is measured by the Southern Oscillation Index. For 10 points, name this periodic climatic effect centered around the warming of the eastern Pacific ocean.
An instance of this effect is credited by some historians as setting off the famines that energized the French Revolution, while another is tied to the demise of the Moche civilization.
{El Niño}-Southern Oscillation [or {ENSO}; prompt on "Southern Oscillation"]