AZORES HIGH

It large persistent atmospheric high-pressure centre that develops over the subtropical region of the eastern North Atlantic Ocean and western Europe during the winter and spring seasons in the Northern Hemisphere
It is associated with anticyclonic winds in the subtropical North Atlantic. It is formed by dry air aloft descending the subtropics and coincides with the downward branch of the Hadley Circulation.
Azores high is also called Bermuda high, Azores anticyclone, or Bermuda-Azores high.
It is a subtropical high-pressure cell that moves westward during the summer and fall when it is known as the Bermuda high.
The Bermuda high is often associated with warm humid weather in the eastern United States during the summer months.
It forms one pole of the North Atlantic oscillation, the other being the Icelandic Low.
The system influences the weather and climatic patterns of vast areas of North Africa and Southern Europe, and to a lesser extent, eastern North America.
The Sahara Desert's aridity and the Mediterranean Basin's summer drought are due to the large-scale subsidence and sinking motion of air in the system.

2. Weather associated with Azores High

An annual drying of 5-10 millimetres per year per decade has been recorded in the Iberian Peninsula throughout the second half of the 20th century.
A further 10-20 per cent drop in winter precipitation is expected by the end of the 21st century.
These projected changes make agriculture in the Iberian region some of the most vulnerable in Europe. The study projected:

Olive-growing regions in southern Spain will suffer a 30 per cent decline in production by 2100.
Cultivation area in grape-growing regions across the Iberian Peninsula will shrink 25-99 per cent by 2050 due to severe water deficits that will render land unsuitable for viticulture.

3. Expansion of Azores High

The researchers demonstrated that the Azore's High expansion is caused by external climate forces and that atmospheric greenhouse gas concentrations are the sole external forcing responsible for this signal during the industrial era.
Winters with a very large Azores High were substantially more frequent in the industrial age after 1850 than in pre-industrial eras, according to observations and climate model predictions.
Since 1850, simulations of the previous millennium have shown that the industrial era extension of the Azores High is unprecedented, which is "compatible with precipitation proxy evidence from Portugal."
According to the study, the Azores High expansion began after 1850 and intensified in the 20th century, which is compatible with warming caused by human activity.

Share to Social