Climate:- The Q&A of Class 9 NCERT
Climate
1. Choose
the correct answer from the four alternatives given below.
(i) Which
one of the following places receives the highest rainfall in the world?
(a) Silchar
(c) Cherrapunji
(b) Mawsynram (d) Guwahati
(ii) The
wind blowing in the northern plains in summers is known as:
(a) Kaal
Baisakhi (c) Trade Winds
(b) Loo (d) None of the above
(iii) Which
one of the following causes rainfall during winters in north-western
part of
India.
(a) Cyclonic
depression (c) Western
disturbances
(b)
Retreating monsoon (d) Southwest monsoon
(iv) Monsoon
arrives in India approximately in:
(a) Early
May (c) Early June
(b) Early
July (d) Early August
(v) Which
one of the following characterises the cold weather season in India?
(a) Warm days
and warm nights
(b) Warm days and cold nights
(c) Cool
days and cold nights
(d) Cold
days and warm nights
1. What are the controls affecting the
climate of India?
A:- India's
climate is influenced by various factors: latitude, altitude, atmospheric
pressure and wind patterns, proximity to the ocean, ocean currents, and the
relief features of the land.
2. Why does India have a monsoon type of
climate?
A:- India's
climate is significantly shaped by the monsoon winds. Hence, it has a monsoon
type of climate.
3. Which part of India does experience
the highest diurnal range of temperature and why?
A:- The
Indian Desert in the northwestern part of India has an extreme diurnal
temperature range due to the rapid heat absorption and release by the abundant
sand.
Daytime
temperatures can reach 50°C, while nighttime temperatures can drop to around
15°C. Additionally, the absence of an ocean nearby means there's no moderating
influence on the temperature.
4. Which winds account for rainfall
along the Malabar coast?
A:- The
Malabar Coast receives its rainfall from the southwest monsoon winds.
5. What are Jet streams and how do they
affect the climate of India?
A:- Jet
streams, high-altitude westerly winds above 12,000 meters, vary in speed from
110 km/h in summer to 184 km/h in winter. The most consistent jet streams are
the mid-latitude and subtropical ones, playing a role in monsoon season
depressions.
6. Define monsoons. What do you
understand by “break” in monsoon?
A:- Monsoon
refers to the complete reversal of winds over a large area leading to a change
of seasons.
A
"break" in the monsoon refers to alternating wet and dry periods,
where rainfall occurs for a few days, followed by rainless intervals.
7. Why is the monsoon considered a
unifying bond?
A:- While temperature
conditions vary across India, the monsoon imparts a sense of unity. The
seasonal shift in wind systems and associated weather patterns creates a
rhythmic cycle of seasons that unifies the entire nation.
8. Why does the rainfall decrease from
the east to the west in Northern India.
A:- Rainfall
decreases from east to west in Northern India due to a gradual decline in the
humidity of the prevailing winds. As these winds move westward, they lose
moisture, leading to reduced rainfall in that direction.
9. Describe the regional variations in
the climatic conditions of India with the help of suitable examples.
A:- India
exhibits diverse climatic conditions across regions. In northern India, the
cold weather season begins in mid-November, with December and January being the
coldest months. Temperatures range from 10°C to 15°C in the northern plains,
while Chennai on the eastern coast maintains an average of 24°C to 25°C. Frost
is common in the north, and the Himalayan slopes experience snowfall.
As we move
into March, the Deccan plateau records high temperatures of about 38°C. In
April, Gujarat and Madhya Pradesh experience around 42°C, and by May,
northwestern parts see temperatures of up to 45°C. However, peninsular India
maintains lower temperatures due to the moderating influence of the oceans.
This variation in temperatures showcases the regional diversity of India's
climate.
10. Discuss the mechanism of monsoons.
A:- The
factors influencing the Indian monsoon are as follows:
(a)
Differential heating and cooling of land and water create low pressure over
India and high pressure over the surrounding seas.
(b) The
shift of the Inter Tropical Convergence Zone (ITCZ) over the Ganga Plain during
summer, which is also known as the monsoon trough.
(c) The
presence of a high-pressure area east of Madagascar at approximately 20°S over
the Indian Ocean, which significantly impacts the Indian Monsoon.
(d) The
intense heating of the Tibetan Plateau during summer, leading to strong
vertical air currents and low pressure formation at a high altitude of about 9
km above sea level.
(e) The
movement of the westerly jet stream north of the Himalayas and the presence of
the tropical easterly jet stream over the Indian peninsula during summer play a
crucial role in the monsoon dynamics.
11. Give an account of weather conditions
and characteristics of the cold season.
A:- The Cold
Weather Season in India, spanning from mid-November to February, is
characterized by distinct weather conditions:
- Clear
skies, low temperatures, and low humidity prevail during this period.
- Winds are
generally feeble and variable.
-
Temperature decreases from south to north, with the peninsular region
experiencing less noticeable temperature changes due to the moderating
influence of the sea.
- December
and January are the coldest months, with warm days and cold nights.
- Frost is
common in the northern parts, and the higher Himalayan slopes receive snowfall.
-
Sub-tropical westerly jet streams south of the Himalayas bring cyclonic
disturbances from the Mediterranean, resulting in winter rains on the plains
and snowfall in the mountains.
- The Tamil
Nadu coast also experiences winter rainfall due to the north-east trade winds
blowing from the sea to the land.
12. Give the characteristics and effects
of the monsoon rainfall in India.
A:- Characteristics
of monsoon rainfall in India include:
(i) Monsoon
duration of 100 to 120 days, typically from early June to mid-September.
(ii) A
sudden increase in rainfall, known as the 'burst' of the monsoon, occurs around
its arrival.
(iii)
Monsoons feature wet and dry spells or 'breaks' in rainfall, with rain
occurring for a few days at a time, interspersed with rainless intervals.
(iv) The
uncertain character of monsoon rains is influenced by pulsating southwesterly
winds affected by different atmospheric conditions, leading to highly variable
annual rainfall.
(v) Rainfall
is unevenly distributed across India, with maximum rainfall in parts of the
western coast and northeastern regions, while some areas like parts of
Rajasthan, Gujarat, Leh, and the leeward side of the Western Ghats receive very
little rainfall.
Effects
of monsoon rainfall in India:
(a) Indian
agriculture heavily relies on monsoon water, and late, insufficient, or
excessive rains can negatively impact crops.
(b) Uneven
rainfall distribution leads to drought-prone and flood-affected regions across
the country.
(c) The monsoon shapes India's distinct climatic pattern, providing a unifying influence despite regional variations, uniting the country and its people.
As we conclude our exploration into the questions and answers of the Class 9 NCERT Climate chapter, it's evident that the study of our planet's climate is not merely a lesson in academia; it's a call to action. The more we unravel the intricacies of Earth's climate system, the more we realize our interconnectedness with the environment. From understanding the impact of human activities on climate change to appreciating the delicate dance of ecosystems, each answer unveils a layer of responsibility and awareness. Armed with knowledge, the Class 9 students are not just students; they are stewards of the Earth's future. The questions posed in the NCERT textbook serve as beacons, guiding us toward a sustainable and harmonious coexistence with nature. As we reflect on the lessons learned, let's carry the torch of environmental consciousness into our daily lives. The journey to comprehend the climate is ongoing, and with each answer discovered, we inch closer to creating a world where questions about the health of our planet become less daunting and more hopeful. In the grand symphony of nature, may our understanding be the melody that harmonizes with the Earth's rhythm.
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