Zhang et al. (2025) Evaluation of CMIP6 models in simulating the impact of rapid decay El Niño events on the Hadley Circulation

Identification

• Journal: Atmospheric Research
• Year: 2025
• Date: 2025-10-10
• Authors: T. L. Zhang, Juan Feng, Falei Xu, Shuang Wang, Xuanliang Ji
• DOI: 10.1016/j.atmosres.2025.108530

Research Groups

• State Key Laboratory of Remote Sensing Science, Faculty of Geographical Science, Beijing Normal University, Beijing, China
• Beijing Engineering Research Center for Global Land Remote Sensing Products, Faculty of Geographical Science, Beijing Normal University, Beijing, China
• State Key Laboratory of Satellite Ocean Environment Dynamics, National Marine Environmental Forecasting Center, Beijing, China

Short Summary

This study evaluates 27 CMIP6 models' ability to simulate Hadley Circulation anomalies during rapid decay El Niño events, finding that models with cold sea surface temperature biases in the Indo-Pacific Warm Pool underestimate these anomalies and exhibit structural deviations.

Objective

• To evaluate whether state-of-the-art Coupled Model Intercomparison Project 6 (CMIP6) models can adequately capture the Hadley Circulation (HC) anomalies associated with rapid decay (RD) El Niño events.
• To examine the physical causes underlying performance differences among CMIP6 models in simulating HC anomalies during RD El Niño events.

Study Configuration

• Spatial Scale: Tropical atmosphere, Indo-Pacific Warm Pool (IPWP).
• Temporal Scale: Interannual variability, focusing on the decaying phase of El Niño events.

Methodology and Data

• Models used: 27 Coupled Model Intercomparison Project 6 (CMIP6) models.
• Data sources: Observations (for comparison), CMIP6 model simulations.

Main Results

• CMIP6 models are categorized into Type I (better performance) and Type II (less satisfactory performance) based on their ability to simulate the spatial characteristics of Hadley Circulation (HC) anomalies during rapid decay (RD) El Niño events.
• Type I models reasonably capture the observed HC anomalies associated with RD events.
• Type II models underestimate HC anomalies and exhibit evident structural deviations compared to observations.
• Type II models show cold sea surface temperature anomaly (SSTA) biases in the Indo-Pacific Warm Pool (IPWP), which lead to reversed meridional SST gradients compared to observations.
• These anomalous SST distributions in the IPWP are identified as the primary cause for the deviations in the spatial structure of HC anomalies in Type II models.

Contributions

• Identifies the anomalous sea surface temperature distribution in the Indo-Pacific Warm Pool during rapid decay El Niño events as a crucial factor limiting the performance of CMIP6 models in reproducing related Hadley Circulation variations.
• Provides a reference for improving the simulation of tropical air-sea interactions, particularly during rapid decay El Niño events, in climate models.
• Underscores the importance of considering different decay rates of El Niño events in model evaluations and climate research.

Funding

• Not specified in the provided text.

Citation

@article{Zhang2025Evaluation,
  author = {Zhang, T. L. and Feng, Juan and Xu, Falei and Wang, Shuang and Ji, Xuanliang},
  title = {Evaluation of CMIP6 models in simulating the impact of rapid decay El Niño events on the Hadley Circulation},
  journal = {Atmospheric Research},
  year = {2025},
  doi = {10.1016/j.atmosres.2025.108530},
  url = {https://doi.org/10.1016/j.atmosres.2025.108530}
}