Model Performance Metrics and Process Diagnostics for Boreal Summer Monsoon Intraseasonal Variability Applied to the GASS-YOTC Multi-Model Physical Processes Experiment

While intraseasonal variability (ISV) exerts profound impacts on the boreal summer Asian monsoon, shortcomings in our knowledge of key processes limits our capability for providing skillful subseasonal (~2-4 week) forecasts of the monsoon. Motivated by the urgent need to improve monsoon forecasting and reduce deficiencies in representing the ISV in climate models, a global model evaluation project on vertical structure and diabatic processes of ISV, namely the MJO, was jointly coordinated by the YOTC/WGNE MJO Task Force and GEWEX Atmospheric System Study (GASS) program. Following parallel lines of inquiry as the MJO Task Force has done with the MJO, we utilize previously proposed and newly developed model performance metrics and process diagnostics, and apply them to the 26 climate model contributions to MJOTF/GASS project. Based on the outcomes of this analysis, we will report on the fidelity of a broad set of contemporary models at representing the MJO, how our findings relate to similar efforts for the boreal winter MJO, and the implications for processes that underpin the ISV of the monsoon.