Kelvin Wave and the Madden-Julian Oscillation in Aqua-plant Simulations by the Naval Research Laboratory Spectral Element Atmospheric Model (NSEAM).

摘要

The Naval Research Lab (NRL) Spectral Element Atmospheric Model (NSEAM) with full physics included is used to investigate the organization and propagation of equatorial waves under the aqua-planet conditions. The sensitivity of the simulation to the distribution of the vertical levels and selected details of the model s precipitation physics is discussed utilizing simulated convective precipitation with the aid of the time-longitude plots and spectral diagrams. It is shown that the Kelvin wave simulation depends strongly on the details of the vertical level distribution and the methods associated with the lifting condensation level. While significant variability is found among the aqua-planet simulations by global atmospheric models, the new model captures the essential interaction between the dynamics and physics of the atmosphere such that the simulated speed and spectrum of the eastward propagating Kelvin waves and the signature of the Madden-Julian Oscillation are as approximately predicted by simplified theory and limited observations.