Assessment of the Ability of CMIP6 GCMS to Simulate the Boreal Summer Intraseasonal Oscillation Over Southeast Asia

The boreal summer intraseasonal oscillation (BSISO) plays an important role in the variability of a wide range weather and climate phenomena across region modulated by Asian monsoon system. This study evaluates strengths weaknesses 19 Coupled Model Intercomparison Project Phase 6 (CMIP6) models to reproduce basic characteristics BSISO. models' rainfall largescale climates are evaluated against GPCP ERA5 reanalysis datasets. All exhibit variance 30–60-day bandpass-filtered convection anomalies but with diverse magnitude when compared observations. CMIP6 capture structure eastward/northward propagating BSISO at wavenumbers 1 2 struggle intensity location signal. Nevertheless, show good ability simulate power spectrum coherence squared principal components combined empirical orthogonal function (CEOF) can distinction between CEOF modes red noise. Also, result shows that some coherent features as indicated Hovmöller diagram. contribution latent static energy relationship moist over Southeast Asia is also simulated selected models, albeit signals weak. Taking together, represent summertime region, BSISO, biases still exist.