Juan Jesús González Alemán
Superior State Meteorologist. AEMET.
The expansion of the Azores anticyclone observed in the last tens of years is unprecedented in the last 1,200 years. Yes, it's a big headline in climate science, a fact that helps to definitively answer the oft-repeated debate on whether climate change is already affecting the very climate machinery of our region, southwest Europe, beyond temperature-related events.
Because it is: the study published this week in the journal Nature Geoscience shows that the expansion of the Azores anticyclone is responsible for the anomalous drought conditions affecting the entire western Mediterranean, including the Iberian Peninsula. In other words, climate change interferes with processes related to atmospheric circulation.
The expansion of the Azores anticyclone is responsible for the anomalous drought conditions affecting the entire western Mediterranean, including the Iberian Peninsula
This is crucial in the debate and will silence many dissenting voices. It is also a very robust study, combining different observational techniques and supported by climate model simulations. It is not only of interest in our region of south-west Europe, but also on a global scale.
The Azores anticyclone is now more extensive (mainly to the north) due to anthropogenic emissions that are causing climate change. This change in its behaviour is causing a decrease in winter precipitation in the region, especially on the Atlantic side, by diverting the typical trajectory of winter squalls to the north.
This has important socio-economic consequences in Spain because it affects important economic activities in the agricultural sector, as well as the water resource, and probably the wind resource. It is undoubtedly a very worrying study.
While it is true that the work is not perfect and has several uncertainties associated with it, as it could have been complemented with more observational data and simulations, it is a good indication of the changes that are taking place, and on which more research should be done.
Furthermore, it should not be forgotten that these changes are in line with what is expected in the future according to the latest climate change projections of the Intergovernmental Panel on Climate Change (IPCC), which foresee a worsening of this behaviour due to large-scale processes in atmospheric dynamics that are affected by climate change.
In short, it is no more than what has been predicted for more than 20 years: climate change is pushing desert climate conditions northwards, which will make the Iberian Peninsula increasingly similar to North Africa.