El Niño as a challenge for Global Climate Models

The El Niño Phenomenon affects the climatological state in the tropical Pacific ocean, changing typical characteristics in temperature, pressure and precipitation usually present in the ocean and continental regions. This work compile some of the main results shown in different intercomparison studies that describe how the models used in the last years simulate important characteristics of El Niño phenomenon compared with their predecessor versions. The criteria commonly used to get model comparisons is how well they show some characteristics such as the general temperature behavior (climatological mean state), changes along the year-session (seasonal variability), how often it occurs (periodicity), the relation between pressures and temperature (southern oscillation index) or spatial temperature, pressure and precipitation (ENSO composites), which are also treated in this paper. Recent global climate models seem to have better results in representing warm events than their predecessor versions, but, do we know the aspects that define an accurately representation? Have been isolated the model improvements that finally reached this better results? We will address these questions in this article. El Niño as a challenge for General Climate Models 2 1