Atlantic Zonal Mode-Monsoon teleconnection in CMIP6 Models

Atlantic Zonal Mode (AZM) and Indian summer monsoon rainfall (ISMR) are known to have an inverse relationship, which means that the cold (warm) phases of AZM result in strong (weak) ISMR. The realistic simulation of AZM and its teleconnection with ISMR in coupled models is important for the better seasonal prediction of ISMR. Here, we evaluated the performance of 26 CMIP6 models in simulating the AZM-ISMR teleconnection using 40 years of historical simulations. The skill of most CMIP6 models in simulating the teleconnection between AZM and ISMR is poor. Out of the 26 models analyzed, only 10 models show the correct sign of AZM related rainfall response over central India. The underlying mechanism responsible for the models' failure in capturing AZM-teleconnection is studied using the large-scale dynamical/thermodynamical variables. By choosing a set of good and bad models we unravel the common biases responsible for the wrong teleconnection between AZM-ISMR. This study highlights the importance of correcting AZM‐ISMR teleconnection in climate models for better seasonal monsoon prediction.