27 June 2026

Photo: MPI-M / Dakuan Yu

Summary of ICON XPP model performance across different categories of ENSO metrics—tropical climatology, ENSO characteristics, feedbacks, and teleconnections—comparing the fully coupled reference run (“Fully coupled model reference”, red point), optimized coupled model experiment ("Optimized run_coupled", green cross), fully coupled high resolution run for ICON XPP model (“high resolution_coupled”, black rectangle), optimized coupled-model experiment with global mean temperature (GMT) correction (“Optimized run_coupled_GMT”, yellow triangle). The CMIP6 distribution is shown as a boxplot with the box representing the interquartile range (25th–75th percentile), the central line indicating the median, and whiskers showing the full model spread (minimum to maximum).

A new study led by Dakuan Yu and colleagues demonstrates how systematic parameter optimization can improve the simulation of El Niño and La Niña in the ICON XPP Earth System Model. By identifying which atmospheric parameters have the strongest influence on tropical Pacific climate variability, the team developed a framework that significantly improves key aspects of El Niño-Southern Oscillation (ENSO) behavior, including its amplitude, seasonality, and climate feedbacks. The work provides a new pathway for improving climate model performance and contributes to the ongoing development of ICON XPP Earth system model for climate prediction and projection.

Yu, D., Dommenget, D., Pohlmann, H., and Müller, W. A.: A systematic atmospheric parameter optimization method to improve ENSO simulation in the ICON XPP Earth system model, Geosci. Model Dev., 19, 5531–5552, https://doi.org/10.5194/gmd-19-5531-2026, 2026.

This work is part of Task 1.1 of the Coming Decade project.