Analysis of convectively coupled Kelvin waves in 15 WCRP CMIP3 models

Output from 15 global coupled models is analyzed for the existence and structure of convectively coupled Kelvin waves. Waves are isolated using a wavenumber-frequency spectral filtering technique, and composite structures are calculated via linear regression. The resulting 3-dimensional dynamical and thermodynamical wave structures are then compared to observations of convectively coupled Kelvin waves based on satellite and radiosonde data for the 1979-2006 period.

Model data are obtained from the World Climate Research Program's (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset. Specifically, data from the “Climate of the 20th Century Experiment” are utilized in this study.

Preliminary results suggest that model Kelvin waves typically propagate faster than observed waves. Waves in several models contain fairly realistic horizontal and vertical structures.