Vicente‐Serrano et al. (2017) An updated review on recent trends in observational surface atmospheric variables and their extremes over Spain

Identification

• Journal: Cuadernos de Investigación Geográfica
• Year: 2017
• Date: 2017-01-18
• Authors: Sergio M. Vicente‐Serrano, Ernesto Rodríguez Camino, Fernando Domínguez‐Castro, Ahmed El Kenawy, César Azorín-Molina
• DOI: 10.18172/cig.3134

Research Groups

• Instituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas, Zaragoza, Spain
• Agencia Estatal de Meteorología (AEMET), Madrid, Spain
• Department of Geography, Mansoura University, Mansoura, Egypt
• Regional Climate Group, Department of Earth Sciences, University of Gothenburg, Sweden

Short Summary

This article synthesizes recent findings on observed atmospheric variables and their extremes over Spain, revealing an overall warming of approximately +0.3 °C⋅decade⁻¹ since the 1960s, a significant decrease in relative humidity, increased atmospheric evaporative demand, and complex, often decreasing, precipitation trends, collectively pointing to a warmer and drier climate scenario.

Objective

• To review the state-of-the-art findings on recent trends in observed surface atmospheric variables (solar radiation, air temperature, wind speed, surface humidity, precipitation, evapotranspiration) and their extremes in Spain, focusing on peer-reviewed articles published within the last decade.

Study Configuration

• Spatial Scale: Spain, including Peninsular Spain and specific regions (e.g., Catalonia, Balearic Islands, Canary Islands, Ebro River Basin, southern Spain, northeastern Spain, central plateau, Valencia region, Extremadura).
• Temporal Scale: The review covers studies published in the last decade, with the analyzed climate data typically spanning periods from the 1960s or 1980s up to 2011-2014, and some series extending back to the early 20th century or even the 18th century.

Methodology and Data

• Models used: Penman-Monteith scheme (for reference evapotranspiration), extreme value theory (for temperature and precipitation extremes), statistical models (e.g., gamma distribution for daily precipitation probability).
• Data sources: Peer-reviewed articles (for the review itself), observational data from meteorological stations (e.g., temperature, precipitation, wind speed, sunshine duration, Piché atmometer, pan evaporimeters), radiosonde data, and reanalysis datasets (e.g., ERA-40).

Main Results

• Solar Radiation: A strong increase (brightening) has been observed since the 1980s, with a significant upward trend of 3.9 W⋅m⁻²⋅decade⁻¹ between 1985 and 2010, peaking in summer (6.5 W⋅m⁻²⋅decade⁻¹). This brightening is attributed to changes in cloud cover (75%) and aerosol concentrations (25%).
• Air Temperature:
  • Mean: An overall increase of approximately +0.3 °C⋅decade⁻¹ since the 1960s, with accelerated warming during summer. A slowdown in warming rates (hiatus) was noted from the mid-1990s, particularly for maximum temperature and during the cold season.
  • Extremes: A general decrease in cold events and a notable increase in warm events and heat waves. Warm days increased by 1.1%⋅decade⁻¹, while cold nights decreased by -1.3%⋅decade⁻¹. The summer season length increased by 5 to 12 days⋅decade⁻¹ between 1979 and 2012.
• Wind Speed: A slight, generally non-significant downward trend of -0.016 m⋅s⁻¹⋅decade⁻¹ was recorded from 1961-2011. Seasonal patterns show declines in winter-spring and increases in summer-autumn. Daily peak wind gusts became less frequent and declined in the cold season, but increased in frequency and magnitude during the warm season.
• Surface Humidity: A remarkable decrease in relative humidity (-5% between 1961 and 2011) was observed across mainland Spain, most pronounced in spring (-1.02%⋅decade⁻¹) and summer (-1.56%⋅decade⁻¹). Specific humidity showed no overall change, except for an increase in spring.
• Precipitation: Exhibits strong spatial and temporal variability. Average annual precipitation showed a moderate decrease over the past five decades, with a statistically significant decrease of -18.7 mm⋅decade⁻¹ for 1961-2011. Studies indicate an increase in precipitation concentration, a reduction in the wet season length, and a higher proportion of autumn precipitation in the annual total.
  • Extremes: High uncertainty in trends for daily extreme precipitation events, though most studies suggest a decrease in daily precipitation intensity and an increase in days with low precipitation. Some analyses indicate a potential increase in the most severe events (e.g., 20-year return level).
• Snow Precipitation: Trends are inconclusive and highly dependent on the analysis period. Some studies report a significant decrease in annual snow days (around -50%) since the mid-1970s, while others find insignificant trends for different periods.
• Atmospheric Evaporative Demand (AED) / Reference Evapotranspiration (ETo): A strong increase of +24.4 mm⋅decade⁻¹ was observed at the annual scale across Spain from 1961-2011, with the largest increase in summer (12 mm⋅decade⁻¹). This trend is primarily driven by decreased relative humidity and increased maximum temperature.
• Droughts: Increased drought frequency and severity in most of Spain, attributed to both precipitation decrease and the rise in atmospheric evaporative demand.

Contributions

• Provides an updated and comprehensive synthesis of recent trends in a broad range of observed surface atmospheric variables and their extremes over Spain, extending previous reviews by including variables such as solar radiation, wind speed, surface humidity, and evapotranspiration.
• Consolidates quantitative trends and highlights spatial and temporal patterns across numerous studies published in the last decade.
• Elucidates the complex drivers of climate change in Spain, such as the roles of clouds and aerosols in solar radiation changes, and the combined influence of humidity and temperature on evaporative demand and drought severity.
• Confirms a consistent trend towards a warmer and drier climate scenario in Spain, aligning with observations in other Mediterranean regions.

Funding

• Research project PCIN-2015-220
• Research project CGL2014-52135-C03-01
• Red de variabilidad y cambio climático RECLIM (CGL2014-517221-REDT), financed by the Spanish Commission of Science and Technology and FEDER
• LIFE12 ENV/ES/000536-Demonstration and validation of innovative methodology for regional climate change adaptation in the Mediterranean area (LIFE MEDACC), financed by the LIFE programme of the European Commission
• IMDROFLOOD, financed by the Water Works 2014 co-funded call of the European Commission

Citation

@article{VicenteSerrano2017updated,
  author = {Vicente‐Serrano, Sergio M. and Camino, Ernesto Rodríguez and Domínguez‐Castro, Fernando and Kenawy, Ahmed El and Azorín-Molina, César},
  title = {An updated review on recent trends in observational surface atmospheric variables and their extremes over Spain},
  journal = {Cuadernos de Investigación Geográfica},
  year = {2017},
  doi = {10.18172/cig.3134},
  url = {https://doi.org/10.18172/cig.3134}
}