Ayugi et al. (2025) Physical Predictand Drivers and Characteristics of Aridity Across East Africa

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

Identification

• Journal: International Journal of Climatology
• Year: 2025
• Date: 2025-12-09
• Authors: Brian Ayugi, Kyaw Than Oo, Edovia Dufatanye Umwali, Donnata Alupot
• DOI: 10.1002/joc.70212

Research Groups

Not specified in the abstract.

Short Summary

This study investigates the expansion or contraction of aridity in East Africa over 34 years and identifies its dominant climatic drivers. It finds that temperature fluctuations exert a stronger influence on aridity patterns than precipitation, explaining 82.2% of the total variance, and regional aridity significantly correlates with major climate indices.

Objective

• To investigate whether aridity in East Africa is expanding or contracting in response to global warming and to identify the dominant climatic drivers of these trends.

Study Configuration

• Spatial Scale: East Africa, including eastern Kenya, central Tanzania, the Lake Victoria Basin, and Uganda.
• Temporal Scale: 34 years (past 34 years from the study's timeframe).

Methodology and Data

• Models used: De Martonne Aridity Index (for aridity assessment and climate classification), Empirical Orthogonal Function (EOF) analysis (for identifying dominant climatic drivers).
• Data sources: Historical climate data (temperature and precipitation) used to calculate the De Martonne Aridity Index.

Main Results

• East Africa predominantly experiences arid and semi-arid conditions, with De Martonne Aridity Index values ranging between 10% and 30%.
• Wet years (1981, 1982, 1986, 2006, 2013) show persistent arid conditions (De Martonne Aridity Index < 10) in eastern Kenya and central Tanzania, while the Lake Victoria Basin and Uganda experience humid conditions (28 ≤ De Martonne Aridity Index < 35%).
• Dry years (1984, 2000, 2005, 2009, 2014) intensify arid and semi-arid conditions across Kenya and Tanzania.
• Temperature fluctuations exert a stronger influence on aridity patterns than precipitation, explaining 82.2% of the total variance in the leading mode (EOF1) compared to 40.2% for rainfall.
• Regional aridity shows significant positive correlations with major climate indices: South Asian Summer Dipole (r = 0.44), Indian Ocean Dipole (r = 0.32), and Nino3.4 (r = 0.16).

Contributions

• Provides a quantitative assessment of aridity changes and climate type classification in East Africa over 34 years using the De Martonne Aridity Index.
• Identifies temperature-driven evaporative demand as the primary climatic driver of aridity patterns in East Africa, demonstrating its significantly greater influence compared to precipitation.
• Establishes significant teleconnections between regional aridity in East Africa and major global climate indices, particularly the South Asian Summer Dipole.
• Highlights the critical need for adaptive strategies in East Africa to mitigate the impacts of increasing temperature-driven aridity on agriculture, water resources, and livelihoods.

Funding

Not specified in the abstract.

Citation

@article{Ayugi2025Physical,
  author = {Ayugi, Brian and Oo, Kyaw Than and Umwali, Edovia Dufatanye and Alupot, Donnata},
  title = {Physical Predictand Drivers and Characteristics of Aridity Across East Africa},
  journal = {International Journal of Climatology},
  year = {2025},
  doi = {10.1002/joc.70212},
  url = {https://doi.org/10.1002/joc.70212}
}