Why do the monsoons retreat?
The land becomes cool, the sun moves towards the Tropic of Capricorn, and low pressure changes to high pressure
This leads to a decrease in the intensity of the south-west monsoons, resulting in their systematic withdrawal.
Explain the mechanism of the westerly depressions.
The sub-tropical high pressure belt moves over the Mediterranean Sea, causing shallow cyclonic depressions to blow north-eastward into Europe
These western disturbances cause winter rainfall in the north-western part of the Indian sub-continent.
What are the characteristics of the advancing south-west monsoon season?
- Occurs from June to September
- Gives rainfall to almost entire India
- Very strong and moisture laden
This season is crucial for the agricultural sector in India.
What are the characteristics of the retreating south-west monsoon season?
- Occurs in October and November
- Gives rainfall only to peninsular India
- Not strong and contains little moisture
This season marks the end of the monsoon period in India.
List three differences between the Retreating south-west monsoons and the North East monsoons.
- Months: Retreating (October and November), North East (December, January, February)
- Direction: Retreating (South West to North East), North East (North-east to South-west)
- Rainfall: Retreating (West Coast), North East (Land to sea)
These differences affect the climatic conditions in the respective regions.
List three differences between the Arabian Sea branch and the Bay of Bengal Branch.
- Source of moisture: Arabian Sea (Arabian Sea), Bay of Bengal (Bay of Bengal)
- Direction: Arabian Sea (South west to north east), Bay of Bengal (South-east to north-west)
- Rainfall: Arabian Sea (Western India), Bay of Bengal (Eastern and Central India)
These branches contribute differently to the monsoon patterns in India.
What are the characteristics of Equable Climate?
- Moderating influence of sea present
- Characteristic of coastal areas
- Annual Range of Temperature is low
This climate type is typically found in regions near large bodies of water.
What are the characteristics of Extreme climate?
- Moderating influence of sea absent
- Characteristic of interior regions
- Annual Range of Temperature is high
This climate type is often found in areas far from oceans or seas.
State the economic importance of Relief rain in Tamil Nadu.
Beneficial for the millets and rice crops
Relief rainfall occurs in regions like Palni, Javadi, and Shevaroy hills.
State the economic importance of Cyclonic Rainfall in Punjab.
Highly useful for rabi crops in Punjab, Haryana, and Western Uttar Pradesh
This type of rainfall supports the agricultural cycle in these regions.
State the economic importance of Mango Showers in Kerala.
Good for the mango trees
These showers occur before the south-west monsoons and help in the early growth of mangoes.
What are the salient features of monsoon rainfall in India?
- Occurs mostly after the summer season
- Erratic and unpredictable
- Very unevenly distributed
- Mainly orographic (relief) in nature
- Also occurs due to cyclones and convection currents
These features significantly impact agriculture and water resources in India.
Calculate the annual rainfall for Station A.
67.6 cm
This is calculated by adding the rainfall received in a year.
What is the annual range of temperature at Station B?
5.6 ˚C
It is the difference between the highest and the lowest temperatures in a year.
In which hemisphere do you think Station A lies?
Northern Hemisphere
This is indicated by having summers in June and winters in December.
Which of these Stations has an equable climate?
Station B
It has a small annual range of temperature (5.6° C), indicating a mild climate.
On which coast of India do these stations lie? Justify your answers.
Both stations are on the western coast
They receive most of the rain from June to September.
