En el presente artículo nos enfocaremos en las fluctuaciones de la TSM que se encuentran sobre la escala de tiempo intraestacional, la cual se refiere a las oscilaciones de las variables climáticas con un periodo que varía entre 30 y 120 días. Cabe mencionar que una parte de esta variabilidad intraestacional proviene de la variabilidad interna del océano y es asociada a la actividad de remolinos de mesoescala. El presente artículo no analiza la variabilidad interna, la cual es más marcada afuera de la zona de afloramiento costero, sino se centra sobre la variabilidad forzada que puede explicar los eventos cálidos o fríos asociados a una alteración del afloramiento promedio dentro de una estación. Es importante predecir tal tipo de evento pues este puede tener un gran impacto sobre el ecosistema marino y sobre el clima costero.

We propose that the first two empirical orthogonal function (EOF) modes of tropical Pacific sea surface temperature (SST) anomalies do not describe different phenomena (i.e., El Niño‐Southern Oscillation (ENSO) and “El Niño Modoki”) but rather the nonlinear evolution of ENSO. We introduce two new uncorrelated indices (E and C), based on the leading EOFs, that respectively account for extreme warm events in the eastern and cold/moderate warm events in the central equatorial Pacific, corresponding to regimes with different evolution. Recent trends in ENSO can be described as an increase in the central Pacific (C) variability that is associated with stronger cold events, as well as a reduction in the eastern Pacific (E) variability within the cold/moderate warm regime, consistent with model projections. However, little can be said observationally with respect to the extreme warm reg...

The Tropical Rainfall Measuring Mission Microwave Imager sea surface temperature (SST) and QuikSCAT wind stress satellite data are used to investigate the intraseasonal upwelling variability along the coat of Peru over the period 2000–2008. Two regions of peak variance correspond to the central Peru region (Pisco region, 15°S) and the northern Peru region (Piura region, 5°S). A covariance analysis reveals a significant coherency between winds and SST anomalies off Pisco, consistent with Ekman pumping and transport dynamics. The upwelling cell consists in a meridionally extended fringe of colder (warmer) water extending as far as 250 km from the coast at 15°S. In the Piura region, the intraseasonal covariability pattern is represented by two modes, one relevant to the direct Ekman dynamics and the other one associated with the remote forcing of intraseasonal oceanic Kelvin wave. Two ...