Sardeshmukh et al. (2025) Learning ENSO Dynamics from Data

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

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-10-07
• Authors: Prashant D. Sardeshmukh, Cécile Penland, Gilbert P. Compo
• DOI: 10.1175/jcli-d-25-0053.1

Research Groups

Not explicitly stated in the abstract.

Short Summary

This study estimates the relative roles of dominant positive and negative feedbacks on El Niño–Southern Oscillation (ENSO) directly from observational data, revealing a critical competition between destabilizing positive feedbacks (zonal wind, subsurface ocean) and a stabilizing negative surface shortwave flux feedback due to cloud shielding, which primarily renders ENSO asymptotically stable.

Objective

• To estimate the relative roles of dominant positive and negative feedbacks on predictable ENSO event magnitudes, patterns, and durations directly from observational data.
• To clarify the predictable dynamics of the coupled Indo-Pacific atmosphere–ocean climate system through feedback-denial experiments.

Study Configuration

• Spatial Scale: Indo-Pacific atmosphere–ocean climate system, focusing on the equatorial Pacific, western Pacific, and Maritime Continent regions.
• Temporal Scale: Seasonal climate anomalies and longer-term predictions; data used spans 1979–2017 (38 years).

Methodology and Data

• Models used: A 15-component linear inverse model (LIM) of the coupled Indo-Pacific atmosphere–ocean climate system.
• Data sources: Observational data and reanalysis data for the period 1979–2017.

Main Results

• The study provides a clear picture of the dominant competition between destabilizing positive feedbacks (near-surface zonal wind and subsurface oceanic feedbacks) and a stabilizing negative surface shortwave flux feedback associated with cloud shielding.
• This negative surface shortwave flux feedback is primarily responsible for rendering ENSO asymptotically stable.
• Underrepresentation of this negative feedback in climate models likely causes them to extend equatorial Pacific warming during El Niño (and cooling during La Niña) too far west, compromising seasonal and longer-term predictions.
• An underrepresentation of this negative feedback over the Maritime Continent is consistent with common climate model biases, including mean sea surface temperature (SST) cold tongue and easterly trade wind biases over the western equatorial Pacific.

Contributions

• Provides the first direct estimation of dominant ENSO feedbacks from observational data, offering a novel understanding of the competition between destabilizing and stabilizing processes.
• Identifies the critical role of negative surface shortwave flux feedback in ENSO's asymptotic stability.
• Offers a data-driven explanation for persistent biases in climate models regarding ENSO representation and its teleconnections, particularly the westward extension of equatorial Pacific temperature anomalies and biases over the Maritime Continent.

Funding

Not explicitly stated in the abstract.

Citation

@article{Sardeshmukh2025Learning,
  author = {Sardeshmukh, Prashant D. and Penland, Cécile and Compo, Gilbert P.},
  title = {Learning ENSO Dynamics from Data},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-25-0053.1},
  url = {https://doi.org/10.1175/jcli-d-25-0053.1}
}