Chen et al. (2026) Different Responses of the Madden‐Julian Oscillation to the Fast and Slow Decaying El Niño in Spring

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

Identification

• Journal: Geophysical Research Letters
• Year: 2026
• Date: 2026-03-25
• Authors: Xiong Chen, Chang Li, Minghao Yang
• DOI: 10.1029/2025gl121588

Research Groups

Not specified in the abstract.

Short Summary

This study investigates how El Niño's decay rate modulates the Madden-Julian Oscillation (MJO) during decaying springs, finding that fast-decaying El Niño weakens MJO activity over the central Pacific, while slow-decaying El Niño significantly enhances it through stronger moisture advection and lower-tropospheric moistening.

Objective

• To investigate the modulation of the Madden-Julian Oscillation (MJO) by El Niño during decaying springs.

Study Configuration

• Spatial Scale: Central Pacific region.
• Temporal Scale: Decaying springs following El Niño events.

Methodology and Data

• Models used: Not specified in the abstract.
• Data sources: Reanalysis data. El Niño events are categorized into fast-decaying (FD) and slow-decaying (SD) types based on their decaying rate.

Main Results

• In fast-decaying (FD) El Niño decaying springs, MJO circulation and convection significantly weaken over the central Pacific.
• In contrast, under slow-decaying (SD) El Niño conditions, MJO circulation and convection are substantially enhanced over the central Pacific.
• SD El Niño induces stronger westerly anomalies, positive moisture anomalies, and anomalous ascending motion over the central Pacific.
• These conditions lead to a weaker low-frequency background moisture zonal gradient and a stronger MJO circulation under SD El Niño.
• Both zonal and vertical moisture advection are much stronger under SD El Niño, resulting in more pronounced lower-tropospheric moistening east of the MJO convection center, thereby enhancing MJO activity.

Contributions

• This study identifies distinct modulations of MJO activity by different El Niño decay types (fast vs. slow-decaying), providing new insights into the mechanisms behind MJO enhancement under slow-decaying El Niño conditions, specifically highlighting the roles of moisture advection and lower-tropospheric moistening.

Funding

Not specified in the abstract.

Citation

@article{Chen2026Different,
  author = {Chen, Xiong and Li, Chang and Yang, Minghao},
  title = {Different Responses of the Madden‐Julian Oscillation to the Fast and Slow Decaying El Niño in Spring},
  journal = {Geophysical Research Letters},
  year = {2026},
  doi = {10.1029/2025gl121588},
  url = {https://doi.org/10.1029/2025gl121588}
}