Saari et al. (2025) Synchronisation of Extreme Precipitation and Sea Surface Temperature Events in the Northern Hemisphere: A Complex Network Approach

⚠️ 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: 2025-12-14
• Authors: Connor Saari, Jürgen Kurths, Gabriele Villarini, Behzad Ghanbarian
• DOI: 10.1002/joc.70218

Research Groups

Not specified in the abstract.

Short Summary

This study analyzed spatiotemporal patterns and connections between inland extreme precipitation events (EPEs) and extreme sea surface temperature events (ESSTEs) in the Northern Hemisphere from 1930 to 2020, revealing distinct network characteristics and increasing trends for both event types after 1980.

Objective

• To analyze the spatiotemporal patterns of inland extreme precipitation events (EPEs) and extreme sea surface temperature events (ESSTEs) in the Northern Hemisphere (0°N–60°N) to better understand their connection.

Study Configuration

• Spatial Scale: Northern Hemisphere (0°N–60°N)
• Temporal Scale: 1930 through 2020 (91 years)

Methodology and Data

• Models used: Event synchronisation (ES) method, null model distribution for comparison, complex network analysis (calculating degree centrality, mean geographic distance (MGD), and clustering coefficient).
• Data sources: Gridded monthly gauge- and interpolation-based datasets for precipitation and sea surface temperature. Extreme events were detected using the 95th percentile threshold.

Main Results

• Both EPEs and ESSTEs exhibited non-monotonic trends over the past nine decades, with significant increasing trends observed after 1980.
• Key EPE network hubs were identified in Mexico, the African Sahel, and parts of Asia.
• ESSTE hubs were found in the Atlantic Ocean near the UK and US borders, the Pacific Ocean close to East Asia, and the Mediterranean and Red Seas.
• The EPE network showed larger mean geographic distances (MGDs) and more intense local clustering in continental areas (Sahel and East Asia), indicating the presence of teleconnections alongside strong local associations.
• In contrast, the ESSTE network had lower MGD values and close clustering within specific ocean basins, consistent with localized ocean-atmosphere coupling.

Contributions

• Provides novel insights into the complex drivers of extreme climate events by analyzing and contrasting the network characteristics (synchronization, hubs, MGD, clustering) of extreme precipitation and sea surface temperature events.
• Highlights the distinct spatial scales of teleconnections for continental extreme precipitation (larger MGD, local clustering) versus oceanic extreme sea surface temperatures (lower MGD, localized clustering).
• Contributes to understanding the spatiotemporal evolution and interconnectedness of extreme climatic events across the Northern Hemisphere.

Funding

Not specified in the abstract.

Citation

@article{Saari2025Synchronisation,
  author = {Saari, Connor and Kurths, Jürgen and Villarini, Gabriele and Ghanbarian, Behzad},
  title = {Synchronisation of Extreme Precipitation and Sea Surface Temperature Events in the Northern Hemisphere: A Complex Network Approach},
  journal = {International Journal of Climatology},
  year = {2025},
  doi = {10.1002/joc.70218},
  url = {https://doi.org/10.1002/joc.70218}
}