Climate of the Pyrenees: Extremes indices and long-term trends

Area of Science:

• Climatology
• Environmental Science
• Meteorology

Background:

• The Pyrenees mountain range presents complex climate dynamics influenced by its transboundary nature.
• Understanding regional climate patterns and extreme events is crucial for adaptation strategies.

Purpose of the Study:

• To analyze spatial and temporal climate patterns in the Pyrenees using extensive meteorological data.
• To investigate trends in extreme precipitation and temperature events from the mid-20th century to 2020.

Main Methods:

• Utilized a cross-border dataset from over 1500 meteorological stations (mid-20th century to 2020).
• Applied rigorous data quality control, homogenization, and spatial modeling.
• Generated a high-resolution gridded dataset (1 km²) for daily temperature and precipitation (1981-2020).
• Evaluated long-term trends using homogenized data series (1959-2020).

Main Results:

• Identified clear elevation-related temperature patterns, except for tropical nights on the Mediterranean side.
• Observed a distinct north-south precipitation disparity, becoming longitudinal for extreme events.
• Documented a significant warming trend of 0.2-0.4°C per decade.
• Found non-significant precipitation changes overall, but a decrease of ~3% per decade annually in southern/Mediterranean regions.

Conclusions:

• The Pyrenees are experiencing significant warming trends.
• Precipitation patterns are shifting, with notable decreases in specific regions.
• Elevation and latitude are key factors influencing Pyrenean climate variations.