[Mission 2022] QUIZ – 2022: INSIGHTS STATIC QUIZ, 22 November 2021 – Geography – INSIGHTSIAS

Solution: d)

The monsoons are experienced in the tropical area roughly between 20° N and 20° S. To understand the mechanism of the monsoons, the following facts are important.

(a) The differential heating and cooling of land and water creates low pressure on the landmass of India while the seas around experience comparatively high pressure.

(b) The shift of the position of Inter Tropical Convergence Zone (ITCZ) in summer, over the Ganga plain (this is the equatorial trough normally positioned about 5°N of the equator – also known as the monsoon trough during the monsoon season).

(c) The presence of the high-pressure area, east of Madagascar, approximately at 20°S over the Indian Ocean. The intensity and position of this high-pressure area affects the Indian Monsoon.

(d) The Tibetan plateau gets intensely heated during summer, which results in strong vertical air currents and the formation of high pressure over the plateau at about 9 km above sea level.

(e) The movement of the westerly jet stream to the north of the Himalayas and the presence of the tropical easterly jet stream over the Indian peninsula during summer.

Solution: c)

Due to a low temperature in the winter season, a high pressure develops over north-western India.

In contrast to it, low pressure is found over south India, Arabian Sea and Bay of Bengal.

Therefore, winds blow from north-west to south-east.

Solution: a)

• The currents of the Indian Ocean are modified by the landmass in the north and influenced by the Monsoon winds.
• In the North Indian Ocean, a complete reversal of direction of Monsoon Current, twice a year is observed between summer and winter because the Monsoon winds change their direction according to seasons.

South-West Monsoon Current(warm)

• In the summer season, the monsoon winds blow from south west to north-east. Consequently, the ocean current also flows from south-west to north-east direction.
• The main current moves in the Arabian Sea and the Bay of Bengal along the coast of India.

North-East Monsoon Current (warm)

• In the winter season, the monsoon winds blow from north-east to south-west. The ocean current also flows from north-east to south-west under the influence of these winds.

Solution: b)

Tropical Wet and Dry Climate (Aw): It is found to the north and south of the Amazon forest in Brazil and adjoining parts of Bolivia and Paraguay in South America, Sudan and south of Central Africa. The annual rainfall in this climate is considerably less and is variable also. The wet season is shorter and the dry season is longer with the drought being more severe. Temperature is high throughout the year and diurnal ranges of temperature are the greatest in the dry season. Deciduous forest and tree-shredded grasslands occur in this climate.

Solution: c)

Around September, with the sun fast retreating south, the northern land mass of the Indian subcontinent begins to cool off rapidly. With this air pressure begins to build over northern India, the Indian Ocean and its surrounding atmosphere still holds its heat. This causes cold wind to sweep down from the Himalayas and Indo-Gangetic Plain towards the vast spans of the Indian Ocean south of the Deccan peninsula. This is known as the Northeast Monsoon or Retreating Monsoon.

While travelling towards the Indian Ocean, the dry cold wind picks up some moisture from the Bay of Bengal and pours it over peninsular India and parts of Sri Lanka. Cities like Chennai, which get less rain from the Southwest Monsoon, receives rain from this Monsoon. About 50% to 60% of the rain received by the state of Tamil Nadu is from the Northeast Monsoon.