The Time Sequence and Magnitude of Physical Effects of El Niño in the Eastern Pacific

Abstract

During the years 1982–84 different pinniped populations along the Pacific coasts of the Americas were heavily affected by climatic anomalies over a wide range of latitudes, extending from Alaska in the north to the south of Chile. These anomalies can be related to El Niño (EN), a climatological phenomenon characterized by anomalous conditions in the atmosphere and the ocean. It appears in a somewhat regular time sequence in the tropical Pacific, extends, however, less intensively to the mid-latitudes and beyond. During EN, anomalously warm water appears along the coast of Ecuador and Peru. As an example we show the deviation of the sea surface temperature from the long-term mean at Puerto Chicama (Fig. 1). The magnitude of this positive sea surface temperature (SST) anomaly can be used to classify the intensity of an EN.