Simulation of the Madden–Julian Oscillation in a Coupled General Circulation Model. Part I: Comparison with Observations and an Atmosphere-Only GCM

Abstract In Part I of this study it was shown that air–sea coupling had a positive impact on some aspects of the simulation of the Madden–Julian oscillation (MJO) by a GCM. However, errors in the basic-state climate of that GCM appeared to be preventing the MJO-related convection from propagating into the west Pacific. In this paper, the actual impact of these errors will be addressed. An integration of a flux-adjusted version of the coupled model has been performed, which has reduced basic-state errors in the west Pacific. In this version of the coupled GCM the MJO does propagate into the west Pacific. The simulation of the MJO by a coupled model with the same atmospheric component but a different ocean GCM is also analyzed. This coupled GCM has similar systematic errors in low-level zonal wind and precipitation to the model studied in Part I, but with warmer SSTs. Results from this experiment, together with the other available evidence, suggest that it is the errors in the low-level zonal wind component...

[1]  S. P. Anderson,et al.  Surface meteorology and air-sea fluxes in the western equatorial Pacific warm pool during the TOGA c , 1996 .

[2]  J. Turner,et al.  A one‐dimensional model of the seasonal thermocline II. The general theory and its consequences , 1967 .

[3]  John F. B. Mitchell,et al.  The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments , 2000 .

[4]  Phillip A. Arkin,et al.  Analyses of Global Monthly Precipitation Using Gauge Observations, Satellite Estimates, and Numerical Model Predictions , 1996 .

[5]  Maria Flatau,et al.  The Feedback between Equatorial Convection and Local Radiative and Evaporative Processes: The Implications for Intraseasonal Oscillations , 1997 .

[6]  M. Mcphaden,et al.  Intraseasonal surface cooling in the equatorial western Pacific , 2000 .

[7]  P. Rowntree,et al.  A Mass Flux Convection Scheme with Representation of Cloud Ensemble Characteristics and Stability-Dependent Closure , 1990 .

[8]  H. Hendon,et al.  Mixed Layer Modeling of Intraseasonal Variability in the Tropical Western Pacific and Indian Oceans , 1998 .

[9]  B. Hoskins,et al.  The Relationship between Convection and Sea Surface Temperature on Intraseasonal Timescales , 2000 .

[10]  D. Gregory,et al.  Parametrization of momentum transport by convection. II: Tests in single‐column and general circulation models , 1997 .

[11]  H. Hendon.  Impact of Air-Sea Coupling on the Madden-Julian Oscillation in a General Circulation Model , 2000 .

[12]  J. Slingo,et al.  On the predictability of the interannual behaviour of the Madden‐Julian oscillation and its relationship with el Nin̄o , 1998 .

[13]  Richard Neale,et al.  Organization of tropical convection in a GCM with varying vertical resolution; implications for the simulation of the Madden-Julian Oscillation , 2001 .

[14]  H. Hendon,et al.  Intraseasonal air-sea interaction in the tropical Indian and Pacific Oceans , 1997 .

[15]  P. Delecluse,et al.  OPA 8.1 Ocean General Circulation Model reference manual , 1998 .

[16]  R. Neale,et al.  The Maritime Continent and Its Role in the Global Climate: A GCM Study , 2003 .

[17]  Duane E. Waliser,et al.  The Influence of Coupled Sea Surface Temperatures on the Madden–Julian Oscillation: A Model Perturbation Experiment , 1999 .

[18]  Richard H. Johnson,et al.  Trimodal Characteristics of Tropical Convection , 1999 .

[19]  A. Matthews,et al.  Intraseasonal oscillations in 15 atmospheric general circulation models: results from an AMIP diagnostic subproject , 1996 .

[20]  P. Gent,et al.  Isopycnal mixing in ocean circulation models , 1990 .

[21]  Richard Neale,et al.  Scale interactions on diurnal toseasonal timescales and their relevanceto model systematic errors , 2003 .

[22]  N. Rayner,et al.  Version 2.2 of the Global sea-Ice and Sea Surface Temperature Data Set , 1996 .