Wen et al. (2025) Exploring causal pathways among soil moisture, climate and ocean–atmosphere teleconnection patterns over the drought-prone Greater Horn of Africa

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-11-02
• Authors: Zhuo Wen, Shibo Fang, Xinran Gao, Ricardo Barros Lourenço, Yanru Yu, Jiahao Han, Alemu Gonsamo
• DOI: 10.1016/j.jhydrol.2025.134534

Research Groups

• State Key Laboratory of Sever Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
• School of Earth, Environment & Society, McMaster University, Hamilton, Ontario L8S 4K1, Canada

Short Summary

This study employs a data-driven causal graph discovery algorithm (PCMCI+) to uncover causal relationships among ocean-atmosphere teleconnection patterns (ENSO, IOD), precipitation, temperature, and soil moisture over the drought-prone Greater Horn of Africa (GHOA) from 1980 to 2022, revealing that IOD generally exerts stronger causal effects on soil moisture, primarily mediated through precipitation.

Objective

• To discover causal relationships among El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) teleconnection patterns, precipitation, temperature, and soil moisture (SM) over the drought-prone Greater Horn of Africa (GHOA).
• To quantitatively calculate the causal effects of teleconnection patterns on SM mediated through different climate paths (precipitation and temperature).
• To explore the correlation of these causal relationships with regional drought conditions.

Study Configuration

• Spatial Scale: Greater Horn of Africa (GHOA)
• Temporal Scale: 1980–2022

Methodology and Data

• Models used: PCMCI+ (data-driven causal graph discovery algorithm)
• Data sources: Time series variables for El Niño Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), precipitation, temperature, and soil moisture (SM). Specific data sources (e.g., satellite, reanalysis) are not detailed in the provided text.

Main Results

• The Indian Ocean Dipole (IOD) generally presents higher causal effects on climate variables (temperature and precipitation) and on soil moisture (SM) through both climate pathways than the El Niño Southern Oscillation (ENSO) over most parts of GHOA.
• The strongest correlation with drought conditions is generally found during different IOD phases.
• Precipitation is identified as a more vital path through which teleconnection patterns causally impact SM in GHOA compared to temperature.

Contributions

• Provides the first attempt to quantitatively analyze the causal effects of teleconnection patterns on soil moisture (SM) through both precipitation and temperature pathways.
• Highlights the causal relationships within atmosphere–ocean-climate-soil interactions.
• Offers insights for a better understanding of climate change impact on drought over GHOA.

Funding

• Funding information is not provided in the excerpt.

Citation

@article{Wen2025Exploring,
  author = {Wen, Zhuo and Fang, Shibo and Gao, Xinran and Lourenço, Ricardo Barros and Yu, Yanru and Han, Jiahao and Gonsamo, Alemu},
  title = {Exploring causal pathways among soil moisture, climate and ocean–atmosphere teleconnection patterns over the drought-prone Greater Horn of Africa},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134534},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134534}
}