ISS PREVIOUS YEAR GS 2016 Q.NO. 2(b)

ISS PREVIOUS YEAR GS 2016 Q.NO. 2 (b)

ISS PREVIOUS YEAR GS 2016

ISS PREVIOUS YEAR GS 2016 Q.NO. 2 (b)

Question

What are Western Disturbances and Westerlies, and how are they different from monsoons? In which part of India are they mainly confined?

Solution

1. What are Westerlies?

ISS PREVIOUS YEAR GS 2016 Q.NO. 2 (b)

Westerlies are large-scale global winds that blow from west to east in the middle latitudes of the Earth. They occur between 30° and 60° latitude in both hemispheres.

These winds play an important role in transporting weather systems and moisture across continents. In the Northern Hemisphere, the westerlies influence weather conditions in Europe, Central Asia, and parts of North India during winter.

2. What are Western Disturbances?

Western Disturbances are low-pressure weather systems that originate in the Mediterranean region and move towards India carried by the westerly winds.

When these disturbances reach the Indian subcontinent, they bring winter rainfall and snowfall.

Key features of Western Disturbances:

• Originate in the Mediterranean Sea region

• Travel eastward with the westerlies

• Bring rain in northern plains

• Cause snowfall in the Himalayan regions

• Occur mainly during winter months (December to March)

Western disturbances are very important for winter crops such as wheat and barley in North India.

3. What are Monsoons?

Monsoons are seasonal winds that change direction due to the difference in heating between land and sea.

In India, the monsoon system mainly includes:

1. Southwest Monsoon (Summer Monsoon) – brings heavy rainfall from June to September.

2. Northeast Monsoon (Winter Monsoon) – affects mainly Tamil Nadu and southeastern India.

The monsoon winds carry large amounts of moisture from the oceans, causing widespread rainfall across the country.

4. Difference Between Western Disturbances and Monsoons

Feature	Western Disturbances	Monsoons
Origin	Mediterranean region	Indian Ocean and surrounding seas
Wind Direction	Carried by westerly winds (west → east)	Seasonal winds changing direction
Season	Winter (Dec–Mar)	Summer and winter seasons
Type of Rainfall	Light to moderate winter rain	Heavy seasonal rainfall
Area Affected	Mainly North India	Most parts of India

ISS PREVIOUS YEAR GS 2016 Q.NO. 2 (b)

5. Areas of India Affected by Western Disturbances

Western Disturbances mainly affect North and Northwestern India.

Important regions include:

• Punjab

• Haryana

• Delhi

• Western Uttar Pradesh

• Rajasthan

• Jammu & Kashmir

• Himachal Pradesh

• Uttarakhand

In the Himalayan regions, they bring snowfall, while in the northern plains they cause winter rain and sometimes hailstorms.

Conclusion

Western Disturbances and Westerlies are important winter weather systems that bring rainfall and snowfall to northern parts of India. They are very different from monsoons, which are seasonal winds responsible for the majority of India's annual rainfall. Western disturbances mainly affect North and Northwest India, especially during the winter months, and play a crucial role in agriculture and winter weather patterns.