Azores High (UPSC Current Affairs)

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Why in the news?

A recent study found that the Iberian Peninsula, which is predominantly occupied by Spain and Portugal, has experienced abnormally dry conditions as a result of an extremely massive "Azores High," subtropical weather phenomena

What is meant by Azores High?

• According to the researchers, the Azores High is a subtropical high-pressure system that spans the eastern subtropical North Atlantic and western Europe in the winter.
• In the subtropical North Atlantic, it is connected to anticyclonic winds.
• It is created when dry air ascends from the subtropics and it occurs along the Hadley Circulation's downstream branch.

What are the consequences of Azore high?

• According to data published in the journal Nature Geoscience, the Iberian Peninsula saw yearly drying of 5-10 millimeters per decade throughout the second half of the 20th century.
• By the end of the twenty-first century, it was noted, another 10–20 percent decrease in winter precipitation is anticipated.
• The Iberian region's agriculture is among the most susceptible in Europe as a result of these anticipated changes.
• By 2100, productivity in southern Spain's olive-growing regions would decrease by 30%.
• By 2050, the area under cultivation in grape-growing regions throughout the Iberian Peninsula will have decreased by 25 to 99 percent as a result of severe water shortages that will make the land unfit for viticulture.

What is the reason behind Azores High expansion?

• The researchers demonstrated that the Azores 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.

What are Hadley cells?

• The low-latitude overturning circulations known as Hadley Cells are characterized by air rising near the equator and air sinking at about 30° latitude.
• They regulate low-latitude weather patterns and are in charge of the trade winds in the Tropics.

Some Important FAQs

MCQs

Question: Consider the following statements:

1. In the tropical zone, the western sections of the oceans are warmer than the eastern sections owing to the influence of trade winds.
2. In the temperate Zone, westerlies make the eastern sections of oceans warmer than the western sections

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 and 2

Question: With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct?

1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the southwestern Indian Ocean during January — March.
2. OMT collected during January — March can be used in assessing whether the amount of rainfall in the monsoon will be less or more than a certain long-term mean.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2