Description
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Source: Britannica
Context
Chile and Argentina were recently ranked among the coldest areas on Earth outside of the polar regions due to polar anticyclones.
What is a Polar Anticyclone?
- A polar anticyclone is a wind system that forms at or near the poles due to high air pressure.
- During the winter season, the polar anticyclone is at its fiercest.
- Polar anticyclones include the Siberian anticyclone and the high-pressure system that occurs over Canada and Alaska during the winter months.
- The cooling of surface layers of air creates polar anticyclones.
How a Polar Anticyclone forms?
- The cooling of surface layers of air creates polar anticyclones.
- This cooling leads the air near the surface to become denser, while also causing an inflow of high-level air to replace the denser, sinking air.
- These activities increase the bulk of air above the surface, resulting in the anticyclone. The weather in the center areas of these anticyclones is usually clear and quite chilly. Polar anticyclones have their maximum power near the Earth's surface.
- It frequently migrates eastward and equatorially during the winter, sending chilly waves to milder latitudes. As they migrate closer to the Equator, they bring cool, dry weather during the summer.
- The polar front is the barrier that separates frigid polar air from warmer air, and extratropical cyclones, also known as wave cyclones, originate along this frontal surface.
Source: news.un.org
Practice Question:
Q.Which of the following statements about the Alaknanda River is/are correct?
- The Alaknanda originates from the Satopanth Glacier near Badrinath.
- It meets the Bhagirathi River at Devprayag to form the River Ganga.
- The Mandakini River is a left-bank tributary of the Alaknanda.
Select the correct answer using the code below:
A) 1 and 2 only B) 2 and 3 only C) 1 and 3 only D) 1, 2 and 3
Answer:
D) 1, 2, and 3
Explanation:
- Statement 1: Correct. The Alaknanda River originates from the Satopanth Glacier near Badrinath in Uttarakhand.
- Statement 2: Correct. The Alaknanda meets the Bhagirathi River at Devprayag, and from that point, the combined flow is known as the Ganga.
- Statement 3: Correct. The Mandakini River, which joins the Alaknanda at Rudraprayag, is a left-bank tributary.
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