Selkirk et al. (2026) Coherent interdecadal cycles in global rainfall, temperature, and cloud cover with alignment to Jovian orbital periods

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

Identification

• Journal: Environmental Research Letters
• Year: 2026
• Date: 2026-03-31
• Authors: Tobias Selkirk, AW Western, James Webb
• DOI: 10.1088/1748-9326/ae598f

Research Groups

Not specified in the abstract.

Short Summary

This study identifies significant coherent 12.9- and 19.9-year cycles in global rainfall, surface temperature, and cloud cover, suggesting these interdecadal variabilities are externally paced by Jovian orbital dynamics rather than solely internal climate processes.

Objective

• To identify and characterize significant coherent interdecadal cycles (specifically 12.9- and 19.9-year) in globally gridded datasets of rainfall, surface temperature, and cloud cover.
• To investigate whether these cycles align with external drivers, specifically the orbital dynamics of Jovian planets, and propose a mechanism for their influence on climate variables.

Study Configuration

• Spatial Scale: Global (across approximately 40% of sites in globally gridded datasets).
• Temporal Scale: Interdecadal cycles (12.9 years and 19.9 years). The duration of the datasets used is not specified, but the focus is on these cycle periods.

Methodology and Data

• Models used: Not specified in the abstract (Gaussian clustering of wavelet amplitude power spectrum (GC-WAPS) is a statistical method, not a climate model).
• Data sources: Globally gridded datasets of rainfall, surface temperature, and cloud cover.

Main Results

• Significant coherent 12.9-year and 19.9-year cycles were identified in globally gridded datasets of rainfall, surface temperature, and cloud cover across approximately 40% of sites.
• These cycles represent a redistribution of energy, with spatially balanced regional clusters of positive and negative correlation, rather than an overall heating or cooling effect.
• The identified signals align closely with the orbital dynamics of the Jovian planets, exhibiting a consistent lag of approximately two years.
• A working hypothesis suggests that gravitational perturbations modulate interplanetary dust influx, potentially driving subtle downstream changes:
  • Total cloud cover: approximately 2%
  • Radiative balance: approximately 0.4 kelvin
  • Rainfall: approximately 10%

Contributions

• Provides empirical evidence suggesting that a significant fraction of interdecadal climate variability may be externally paced by Jovian orbital dynamics, challenging the sole attribution to internal stochastic processes.
• Introduces a novel hypothesis linking Jovian gravitational perturbations, interplanetary dust influx, and subsequent changes in cloud cover, radiative balance, and rainfall.
• Offers potential implications for long-term rainfall forecasting by identifying an external driver for interdecadal variability.

Funding

Not specified in the abstract.

Citation

@article{Selkirk2026Coherent,
  author = {Selkirk, Tobias and Western, AW and Webb, James},
  title = {Coherent interdecadal cycles in global rainfall, temperature, and cloud cover with alignment to Jovian orbital periods},
  journal = {Environmental Research Letters},
  year = {2026},
  doi = {10.1088/1748-9326/ae598f},
  url = {https://doi.org/10.1088/1748-9326/ae598f}
}