QBO‐MJO Connection in CMIP5 Models

Abstract

Abstract Recent studies have shown that the quasi‐biennial oscillation (QBO) affects the boreal winter Madden‐Julian oscillation (MJO), its teleconnection, and even its subseasonal prediction skill. Despite its widespread influences, the QBO‐MJO connection has rarely been examined with a climate model. Here, we demonstrate that the QBO‐MJO connection is not well reproduced in the four Coupled Model Intercomparison Project 5 (CMIP5) models that internally generate the QBO. A weak hint of the QBO‐MJO connection is found only in the medium‐resolution Max Planck Institute Earth System Model (MPI‐ESM‐MR). The MJO response to the QBO in this model, however, is not robust and is less organized than that in the observations. The reasons for no or weak QBO‐MJO connection in the climate model simulations are discussed in terms of the underestimated QBO and MJO amplitudes and weak static stability change in response to the QBO in the model.