EL NINO is a temporary change in the climate of the Pacific
ocean, in the region around the equator. You can see its effects in both
the ocean and atmosphere, generally in Northern Hemisphere winter. Typically,
the ocean surface warms up by a few degrees celsius. At the same time,
the place where hefty thunderstorms occur on the equator moves eastward.
Although those might seem like small differences, it nevertheless can have
big effects on the world's climate.