Pérez‐Alarcón et al. (2025) Unveiling the Role of Mediterranean Cyclones in North Africa’s Precipitation

Identification

• Journal: Earth Systems and Environment
• Year: 2025
• Date: 2025-10-27
• Authors: Albenis Pérez‐Alarcón, Rogert Sorí, Amal El-Sehwagy, Ricardo M. Trigo, Luís Gimeno, Zeinab Salah, Milica Stojanovic
• DOI: 10.1007/s41748-025-00905-7

Research Groups

• Centro de Investigación Mariña, Environmental Physics Laboratory (EPhysLab), Universidade de Vigo, Spain
• Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Portugal
• Egyptian Meteorological Authority, Cairo, Egypt
• Departamento de Meteorologia, Universidade Federal do Rio de Janeiro, Brazil
• Climate System Research Unit, UVigo-CESGA, Santiago de Compostela, Spain

Short Summary

This study quantifies the contribution of Mediterranean cyclones (MCs) to precipitation in North Africa (NA) from 1980 to 2024, revealing that MCs account for approximately 9% of total annual precipitation in the region, with significant seasonal and spatial variability.

Objective

• To quantify the contribution of Mediterranean cyclones (MCs) to the annual and monthly precipitation totals in the North Africa (NA) region.

Study Configuration

• Spatial Scale: North Africa region (Morocco, Algeria, Tunisia, Libya, and Egypt). Cyclone tracking domain: 20°−50°N and 10°W−40°E. MC-related precipitation defined within a 400 km radius of the cyclone center.
• Temporal Scale: 1980 to 2024 (45 years). Data resolutions: 6-hourly for ERA5 reanalysis, 3-hourly for MSWEP precipitation.

Methodology and Data

• Models used: Cyclone Tracking framework (CyTRACK)
• Data sources:
  • Multi-Source Weighted-Ensemble Precipitation (MSWEP) dataset (0.1° spatial resolution, 3-hourly temporal resolution).
  • European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 reanalysis data (mean sea level pressure and near-surface wind components, 0.25° spatial resolution, 1-hourly time step, used 6-hourly for CyTRACK).

Main Results

• Approximately 48% of the annual Mediterranean cyclone (MC) count contributes to precipitation in the North Africa (NA) region.
• On average, MCs account for approximately 9% of the total annual precipitation across the entire NA region.
• The highest MC contributions (12–15% annually) are localized over the Atlas Mountains in Algeria and Tunisia, and parts of northern Morocco, with moderate contributions (5–11%) in surrounding coastal areas.
• MC contributions exhibit a marked seasonal cycle, peaking in April (~14%) and dropping to a minimum in August (~2%).
• Statistically significant positive trends in MC contributions (1.5–2.5% per decade) were found in northern and central Algeria, and northeastern Egypt (~1% per decade).
• Statistically significant negative trends (2–2.5% per decade) were concentrated over eastern Libya. No region-wide significant trends were detected.

Contributions

• Provides the first detailed, quantitative climatological assessment of Mediterranean cyclone (MC) contributions to precipitation across the entire North Africa (NA) region, addressing a significant knowledge gap.
• Highlights the crucial role of MCs as a seasonally-timed water source for NA, particularly for the Maghreb subregion.
• Reveals the complex spatial and seasonal variability of MC-related precipitation and identifies heterogeneous regional trends, suggesting a potential linkage between changes in cyclone behavior and regional hydroclimatic variability.
• Emphasizes the importance of understanding MC contributions for improving hydrological management strategies and climate change adaptation in this climate-sensitive region.

Funding

• Xunta de Galicia (Postdoctoral Grant No. ED481B − 2023/016, ED481D − 2024/017, Project Excelencia-ED431F-2024/03, Project ED431C2021/44 - Programa de Consolidación e Estructuración de Unidades de Investigación Competitivas (Grupos de Referencia Competitiva) and Consellería de Cultura, Educación e Universidade).
• Ministerio de Ciencia, Innovación y Universidades, Spain (MICIU/AEI/10.13039/501100011033) (Grant RYC2021 − 034044-I, SETESTRELO project grant no. PID2021 − 122314OB-I00).
• European Union Next Generation EU/PRTR.
• Portuguese Science Foundation (FCT) through the project AMOTHEC (DRI/India/0098/2020).
• MARINA project (04MARINAEGESEOAC3) funded by the ESA EO AFRICA R&D Facility.
• CESGA (Centro de Supercomputación de Galicia) and RES (Red Española de Supercomputación) for computing resources and technical support.
• Universidade de Vigo/Consorcio Interuniversitario do Sistema Universitario de Galicia (Universidade de Vigo/CISUG agreement with Springer Nature) for Open Access funding.

Citation

@article{PérezAlarcón2025Unveiling,
  author = {Pérez‐Alarcón, Albenis and Sorí, Rogert and El-Sehwagy, Amal and Trigo, Ricardo M. and Nieto, Raquel and Gimeno, Luís and Salah, Zeinab and Stojanovic, Milica},
  title = {Unveiling the Role of Mediterranean Cyclones in North Africa’s Precipitation},
  journal = {Earth Systems and Environment},
  year = {2025},
  doi = {10.1007/s41748-025-00905-7},
  url = {https://doi.org/10.1007/s41748-025-00905-7}
}