Previous: The UCLA-GCM Next:Diagnostic Tools Up: Ext. Abst.

The performed simulations

The spatial resolution is of 4º latitude x 5º longitude, with 16 layers in vertical direction, from surface to the 1 hPa level. (one in the PBL, eight in troposphere and seven in stratosphere) for any of the simulations performed here. Time step was of 6 minutes in the calculation of predicted quantities. The physical processes are calculated each hour of simulated time.

We simulate this process by using the UCLA-GCM with two ensembles of 5 simulations each. The two ensembles are driven with different prescribed SST temperature. The first ensemble has the climatological SST for October ("Control" ensemble) as boundary condition, while the other ("Anomaly" ensemble) is driven (or forced) by imposing a monthly average of the anomalous SST for October 1997¹ (EN97, Fig. 5). The ensemble mean of the "Control" simulation fields are considered as the GCM representation of the October-climatological atmospheric circulation, whether the ensemble mean of the "Anomaly" simulations fields are considered as the GCM representation of the atmospheric circulation corresponding to October 1997. Any of the five individual simulation (for each of the two ensembles) is run after specifying the initial condition (with small random modifications among them) for September 15 (simulated date) and last 46 days (but we focus on the last 31 days, corresponding to October).