NUMERICAL STUDY OF QUASI-BIWEEKLY OSCILLATION IN TROPICAL ATMOSPHERE

By using a P-σ incorporated coordinate five-layer primitive equation spherical band model with surface temperature controlled by the heat balance equation,a simulation is done of disturbance formation in an anomalously warm SST area and of the quasi-biweekly oscillation(QBWO) of the disturbance,and associated rainfall and SST with SST being 1/3 period of oscillational phase ahead of rainfall.The study shows that the oscillation is produced by cloud-radiation interaction.Initial anomalously warm SST in the mid-western Pacific causes stronger oscillation than in the eastern.Hence the oscillation gets attenuated during the eastward movement of the disturbance.