Weng et al. (2025) Seychelles Dome Simulated in the CMIP6 Models

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-11-17
• Authors: Yongbiao Weng, Chaoxia Yuan, Jing‐Jia Luo, Toshio Yamagata
• DOI: 10.1175/jcli-d-24-0643.1

Research Groups

Models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6).

Short Summary

This study evaluates the ability of CMIP6 models to reproduce key characteristics of the Seychelles Dome (SD), finding that while the multimodel ensemble mean captures its semiannual oscillation and ENSO relationship, individual models exhibit discrepancies linked to biases in the Intertropical Convergence Zone (ITCZ) and ENSO-driven atmospheric teleconnections, despite overall improvements over previous CMIP phases.

Objective

• To evaluate the reproducibility of key Seychelles Dome (SD) characteristics in models participating in the Coupled Model Intercomparison Project phase 6 (CMIP6).

Study Configuration

• Spatial Scale: Regional (Seychelles Dome in the southwest tropical Indian Ocean), extending to basin-scale (tropical Indian Ocean, eastern tropical Pacific).
• Temporal Scale: Seasonal (semiannual oscillation, seasonal cycle), interannual (El Niño–Southern Oscillation - ENSO), and implications for long-term climate change (global warming projections).

Methodology and Data

• Models used: Coupled Model Intercomparison Project phase 6 (CMIP6) models.
• Data sources: Model outputs from CMIP6 simulations. (No external observational or reanalysis data sources for evaluation are explicitly mentioned in the abstract, only the models themselves are analyzed).

Main Results

• The multimodel ensemble mean effectively captures the unique semiannual oscillation of SD heat content and its close interannual relationship with El Niño–Southern Oscillation (ENSO).
• Substantial discrepancies exist among individual models in both the seasonal cycle and interannual variations of the SD.
• Models struggling to simulate the semiannual oscillation exhibit biases in the location of the Intertropical Convergence Zone (ITCZ) over the tropical Indian Ocean, leading to inaccurate surface wind stress and affected Ekman pumping strength.
• Models poorly simulating the interannual ENSO–SD relationship demonstrate biases in ENSO-driven atmospheric teleconnections to the tropical Indian Ocean.
• Both ITCZ and atmospheric teleconnection biases are closely linked to mean-state sea surface temperatures (SSTs) in the eastern tropical Pacific.
• Increasing eastern tropical Pacific SSTs improves the simulation of the ENSO–SD relationship but deteriorates the simulation of the SD’s seasonal cycle.
• CMIP6 models show an apparent improvement in simulating the SD compared to their precursors (previous CMIP phases).

Contributions

• Provides a comprehensive evaluation of CMIP6 models' ability to simulate the Seychelles Dome, a critical feature in the southwest tropical Indian Ocean.
• Identifies specific atmospheric and oceanic biases (ITCZ location, ENSO teleconnections, eastern Pacific SSTs) in CMIP6 models that contribute to inaccuracies in SD simulation.
• Highlights the trade-offs in model performance when addressing different aspects of SD variability (e.g., seasonal vs. interannual).
• Offers increased confidence in using CMIP6 models for projecting future changes in the Seychelles Dome under global warming, given their improved performance over previous generations.

Funding

Not specified in the abstract.

Citation

@article{Weng2025Seychelles,
  author = {Weng, Yongbiao and Yuan, Chaoxia and Luo, Jing‐Jia and Yamagata, Toshio},
  title = {Seychelles Dome Simulated in the CMIP6 Models},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-24-0643.1},
  url = {https://doi.org/10.1175/jcli-d-24-0643.1}
}