Propagación de variaciones de baja frecuencia en la temperatura superficial del Pacífico nor-oriental

Abstract

We study the propagation o flow frequency variability of sea surface temperature (SST) data (1982-1989) in the north eastern Pacific Ocean. The analysis shows that the SST interannual variability is associated with the El Nifio event of 1982-83. This event appears as a front parallel to the coast and as a warm water intrusion from the ocean interior. The first eigenfunction ( 61%) is associated with the mature phase of El Nifio, and its westward propagation from the coast. The second eigenfunction (29%) is associated with an intrusion from the interior induced by large-scale advection generated by an intensification of the central Pacific winds. This signal is out of phase with the coastal signal by about 18 months. The westward propagation speed of the coastal signal was estimated to be from 3.4 to 1.7 km/day for latitudes less than 25°. The speed and form of this large-scale wave conforms with the theoretical characteristics of a Ross by wave.