The Azores Anticyclone and Iberian Drought: 21st Century Projections
Across large parts of Spain and Portugal, drought conditions have intensified, marking the most severe period recorded in the last 1200 years. This escalation is linked to a high-pressure atmospheric system influenced by climate change, with scientists warning of significant consequences for wine and olive oil production. The Azores anticyclone has expanded in volume, altering the meteorological regime of the Iberian Peninsula and shaping long-term climate trends for Western Europe.
Researchers describe the Azores Anticyclone as a clockwise-rotating high-pressure system over the North Atlantic that now exerts a stronger influence on regional climate. A recent study notes that this system has changed markedly over the past century, with shifts in the North Atlantic climate not seen since the medieval period. Climate model simulations spanning 1200 years show that the anticyclone began to cover a larger area roughly two centuries ago, coinciding with rising greenhouse gas emissions from human activity and accelerating through the 20th century as global warming intensified.
Evidence from Portuguese stalagmites, preserving precipitation records for centuries, indicates that as the Azores Anticyclone expanded, winter rainfall in the western Mediterranean declined. A snapshot of drought in Malaga underscores the real-world impact of these shifts. The study provides a forward-looking forecast of Iberian precipitation, projecting a further 10 to 20 percent reduction by the end of this century. Such a decline would place Iberian agriculture among the most vulnerable in Europe, according to the researchers, who emphasize that the Azores anticyclone is likely to continue expanding as greenhouse gas levels rise, elevating drought risk for staple crops on the peninsula.
These findings carry important implications for predicted hydroclimate changes in the western Mediterranean during the coming decades, highlighting how a shifting high-pressure system can reorganize rainfall patterns across Europe.
The ‘protector’ of the rains
The Azores Anticyclone is described as Europe’s rain guardian by the study. It drives dry air during the summer, producing hot, arid conditions across Portugal, Spain, and much of the western Mediterranean. In contrast, the colder, wetter winters see the high-pressure system expand, channeling rain-bearing westerly winds inland. This winter rain is crucial for both ecological balance and economic vitality in the region, yet it has dwindled notably since the late 20th century.
While some aspects of the anticyclone’s natural variability remain unsettled, the researchers argue that the industrial era expansion of this system is linked to increased atmospheric greenhouse gas concentrations, underscoring the human influence on regional hydroclimate.
Vines may be gone by 2050
The future outlook for agriculture in the Iberian Peninsula carries less reassuring notes. The study projects that vine cultivation could drop by at least a quarter, with the possibility of near disappearance by 2050 due to severe water scarcity. Olive production in southern Spain is also projected to fall, with a potential 30 percent decrease in yields by 2100. In response, winemakers and farmers are exploring adaptation strategies, such as relocating vineyards to higher elevations and adopting more heat-tolerant grape varieties.
These projections help inform policymakers and the agricultural sector as they consider climate resilience measures and water-management strategies to sustain key crops in a warming world. The work cited here draws on comprehensive climate modeling and paleoclimate records to illuminate how human activities are reshaping regional climate patterns over centuries and what that might mean for the near future.
For further study and context, the findings are discussed in a detailed report by researchers in the field of climate science and Western European hydroclimate dynamics. (Nature Geology).