Showing papers by "Rob Allan published in 1997"

The Effect of Greenhouse SSTs on ENSO Simulations with an AGCM

Abstract: The potential for changes to the El Nino–Southern Oscillation (ENSO) phenomenon under enhanced greenhouse conditions is addressed in a series of atmospheric general circulation model (AGCM) experiments with both 1×CO2 and 2×CO2 radiative forcing and prescribed sea surface temperatures. In the first series of experiments, climate anomalies associated with the 1987 “warm” event SSTs are simulated for present-day (1×CO2) conditions. The results reveal realistic large-scale perturbations to mean sea level pressure, rainfall, evaporation, and low-level and upper-level winds compared to simulations using climatological SSTs. In the second series of experiments, the same warm anomalies are superimposed on the equilibrium SSTs calculated during the course of 2×CO2 equilibrium experiments. The resultant SSTs provide an analog warm event for enhanced greenhouse conditions. The simulated climate anomalies for this greenhouse event are similar to those of the present-day event, but, although some changes are...