NCERT Solution For Class 9 Geography Chapter 4
Climate
- 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
(b) Mawsynram
(c) Cherrapunji
(d) Guwahati
Answer:
Mawsynram
NCERT Solution For Class 9 Geography Chapter 4
(ii) The wind blowing in the northern plains in summer is known as:
(a) Kaal Baisakhi
(b) Loo
(c) Trade Winds
(d) None of the above
Answer:
Loo
NCERT Solution For Class 9 Geography Chapter 4
(iii) Which one of the following causes rainfall during winters in the northwestern part of India?
(a) Cyclonic depression
(b) Retreating monsoon
(c) Western disturbances
(d) Southwest monsoon
Answer:
Western disturbances
NCERT Solution For Class 9 Geography Chapter 4
(iv) Monsoon arrives in India approximately in:
(a) Early May
(b) Early July
(c) Early June
(d) Early August
Answer:
Early June
(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
Answer:
Warm days and cold nights.
NCERT Solution For Class 9 Geography Chapter 4
- Answer the following questions briefly.
(i) What are the factors affecting the climate of India?
Answer:
The factors affecting the climate of India are
- Latitude
- Altitude
- Pressure and Winds
NCERT Solution For Class 9 Geography Chapter 4
(ii) Why does India have a monsoon type of climate?
Answer: India is said to have a “monsoon” type of climate. The seasonal change in wind direction that occurs once a year is referred to as the monsoon.
There is a clear seasonal pattern to the monsoon type of climate. Season to season variations in the weather are significant. In the country’s interior, these changes are especially apparent. Although the pattern of rainfall varies, the temperature in the coastal areas does not vary much.
In India, there are four distinct seasons: the monsoon’s advance, retreat, cold, and hot. However, there are some regional differences between these four seasons.
Monsoon winds have a major effect on India’s climate. The monsoon lasts from the beginning of June to the middle of September for 100–120 days.
(iii) Which part of India does experience the highest diurnal range of temperature and why?
Answer: The northwest of India is the region where this phenomenon is occurring. This effect is caused by the Thar desert. Not only that, but there isn’t an ocean in this area to keep the temperature moderate.
(iv) Which winds account for rainfall along the Malabar Coast?
Answer: Rainfall along the Malabar Coast is caused by southwest monsoon winds.
NCERT Solution For Class 9 Geography Chapter 4
(v) What are Jet streams, and how do they affect the climate of India?
Answer: In the troposphere, jet streams are a narrow band of westerly winds that are very high (above 12,000 m). In the summer, they travel at roughly 110 km/h, and in the winter, they reach about 184 km/h. Several distinct jet streams have been detected. The subtropical and mid-latitude jet stream is the most stable. During the monsoon, they are the source of depression.
(vi) Define monsoons. What do you understand by “break” in monsoon?
Answer: The movement of the monsoon trough is linked to monsoon breaks. The trough’s axis continues to move northward or southward for a variety of reasons, which controls the rainfall’s spatial distribution. Good rainfall occurs in the plains when the monsoon trough’s axis passes over them. In contrast, longer dry spells occur in the plains whenever the axis moves closer to the Himalayas, and widespread rain falls in the hilly regions that house the Himalayan rivers’ catchment areas.
NCERT Solution For Class 9 Geography Chapter 4
(vii) Why is the monsoon considered a unifying bond?
Answer: The monsoon has a definite unifying effect on the Indian subcontinent. Seasons are characterised by a regular cycle of weather brought about by changes in wind systems with the changing seasons. Monsoon-specific characteristics include the unpredictability of rain and uneven distribution. This phenomenon is the centre of the Indian landscape, animal and plant life, agricultural calendar, and people’s daily lives, including celebrations. Every year, Indians from east to west and north to south eagerly anticipate the arrival of the monsoon. Because these monsoon winds bring water, they unite the entire nation and initiate agricultural activities. This water’s river valleys combine into a single river valley unit as well.
NCERT Solution For Class 9 Geography Chapter 4
- Why does the rainfall decrease from the east to the west in Northern India?
Answer: The winds become less moist as they proceed in that direction. This is the cause of the decrease in rainfall.
- Give reasons as to why.
(i) Seasonal reversal of wind direction takes place over the Indian subcontinent?
Answer: 1. Seasonal variations in pressure that cause the wind direction to change.
2. El Nino is very important.
NCERT Solution For Class 9 Geography Chapter 4
(ii) The bulk of rainfall in India is concentrated over a few months.
Answer: The South West Monsoon winds determine how much rain falls; by July, it has spread quickly and over most of the nation.
(iii) The Tamil Nadu coast receives winter rainfall.
Answer:
It is because of North-East monsoon winds.
(iv) The delta region of the eastern coast is frequently struck by cyclones.
Answer:
The Bay of Bengal faces frequent pressure changes.
NCERT Solution For Class 9 Geography Chapter 4
(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are drought-prone.
Answer:
Because they fall in the rain shadow region of the Aravali Mountains.
NCERT Solution For Class 9 Geography Chapter 4
- Describe the regional variations in the climatic conditions of India with the help of suitable examples
Answer:
- Northern India experiences its cold weather from mid-November through February. In the northern region of India, December and January are the coldest months. From south to north, the temperature drops. On the eastern coast, the average temperature of Chennai is between 24 and 25 degrees Celsius, while in the northern plains, it varies between 10 and 15 degrees. The nights are cold and the days are warm. The upper Himalayan slopes see snowfall, and frost is a common occurrence in the region.
- The Deccan plateau records a maximum temperature of approximately 38°C in March. In Madhya Pradesh and Gujarat, the average April temperature is approximately 42°C. The northwest region of the nation typically experiences 45°C temperatures in May. The oceans’ moderating effect keeps temperatures in peninsular India lower.
NCERT Solution For Class 9 Geography Chapter 4
- Discuss the mechanisms of the monsoon.
Answer: (a) India’s landmass experiences low pressure while the surrounding seas experience relatively high pressure due to the different temperatures of the land and water.
(b) The movement in the summertime position of the InterTropical Convergence Zone (ITCZ) across the Ganga Plain.This is the equatorial trough, which is typically found approximately 5°N of the equator. When monsoon season arrives, it’s also referred to as the monsoon trough.)
(c) The high-pressure area over the Indian Ocean that is present east of Madagascar, roughly at 20°S. The Indian Monsoon is influenced by this high-pressure area’s position and intensity.
(d) During the summer, the Tibetan Plateau experiences extreme heat, which creates strong vertical air currents and low pressure over the plateau, which is located about 9 km above sea level.
(e) The westerly jet stream’s movement north of the Himalayas and the tropical easterly jet stream’s presence over the Indian peninsula in the summer.
YOU CAN ALSO FOLLOW US ON SOCIAL MEDIA
- Give an account of weather conditions and characteristics of the cold season.
Answer:
Northern India experiences a cold weather season that lasts from mid-November to February. In India’s northern region, December and January are the coldest months. Going northward from the south results in a drop in temperature. Located on the eastern coast, Chennai experiences an average temperature of 24° to 25°C.
Similarly, it varies from 10°C to 15°C in the northern plains. It is hot during the day and cool at night here.The higher slopes of the Himalayas receive snowfall, and frost is a common occurrence there.Northeast trade winds are predominant throughout the nation during this time of year. For the majority of the nation, it is a dry season because they blow from land to sea. Given that these winds blow from the sea to the land, some rainfall falls on the Tamil Nadu coast.
Light winds are moving outward from a weak area of high pressure that forms in the country’s north. These breezes, which originate in the northwest and come from the west, pass through the Ganga Valley. Clear skies, low temperatures, low humidity, and weak, erratic winds are the typical indicators of the weather.
Inflow of cyclonic disturbances from the west and northwest is a defining feature of the cold weather season over the northern plains. As the westerly flow carries these low-pressure systems into India, they form over the Mediterranean Sea and western Asia. Their effect is to bring snowfall in the mountains and much-needed winter rains over the plains. Winter rainfall, or “Mahawat” as it is known locally, is extremely important for the growth of “rabi” crops even though it is not a large amount overall. There’s no distinct cold season in the peninsular region. Since the sea has a moderating effect during the winter, there is hardly any discernible seasonal change in temperature patterns.
NCERT Solution For Class 9 Geography Chapter 4
- Give the characteristics and effects of the monsoon rainfall in India.
Answer:
Unlike the trades, the monsoon has a pulsating nature due to the various atmospheric conditions it encounters while travelling over the warm tropical seas. The monsoon lasts from the beginning of June to the middle of September for 100–120 days. The typical rainfall abruptly increases upon its arrival and persists continuously for a few days.
Different from the pre-monsoon showers, this is referred to as the “burst” of the monsoon. By the first week of June, the monsoon has usually reached the southernmost point of the Indian peninsula. Later on, The two branches that follow are the Bay of Bengal branch and the Arabian Sea branch. About ten days later, on June 10th, the Arabian Seabranch arrives in Mumbai. It’s progressing rather quickly.The branch of the Bay of Bengal also moves quickly, arriving in Assamin during the first week of June.
The monsoon winds are deflected westward over the Ganga Plains by the tall mountains. The central region of the country, Saurashtra-Kachchhand, is covered by the Arabian Sea branch of the monsoon by mid-June.Across the northwest portion of the Ganga Plains, the monsoon branches of the Arabia Sea and the Bay of Bengal combine. The Bay of Bengal branch typically sends Delhi monsoon showers by the end of June (the tentative date is June 29). The monsoon arrives in western Uttar Pradesh, Punjab, Haryana, and eastern Rajasthan by the first week of July. The monsoon makes its way to Himachal Pradesh and the rest of the nation by the middle of July.