Cyclones and Monsoons

09 Jun Cyclones and Monsoons

Cyclones and Monsoons

This article covers “Daily Current Affairs” and the topic details “Cyclones and Monsoons”. The topic “Cyclones and Monsoons” has relevance in the Environment section for the UPSC CSE exam.

Relevance of the topic “Cyclones and Monsoons”:

For Prelims:
What are cyclones?
What are the initial conditions for the onset of monsoons? 

For Mains:
GS 3: Environment
What is the relation between cyclones and monsoons?
What are the recent changes are observed in the pattern of monsoons in relation to cyclones?
Way forward 

Why in the news?

What are cyclones?

Cyclones are powerful tropical storms characterized by low-pressure systems and strong winds that circulate around a central eye. They typically form over warm ocean waters near the equator. 

What are the initial conditions for the onset of cyclones? 

1. Warm ocean waters (at least 26.5°C or 80°F)
2. Atmospheric instability with temperature and moisture differences
3. Coriolis effect, more pronounced at 5-30 degrees latitude
4. Low vertical wind shear
5. Disturbance or tropical wave as a trigger
6. Pre-existing low-pressure system

What is the relation between cyclones and monsoons?

Monsoons play a role in the formation of cyclones. The seasonal reversal of wind patterns during monsoons can contribute to the development of cyclones. As monsoon winds bring in moisture from the ocean, it enhances the atmospheric conditions necessary for cyclone formation.

Cyclones can impact the progress and intensity of monsoon seasons. Cyclones bring intense rainfall and can disrupt normal monsoonal circulation. They can alter wind patterns, temporarily stall or weaken the monsoon, or bring excessive rainfall leading to flooding.

What are the recent changes observed in the pattern of monsoons in relation to cyclones? 

Cyclones can have both positive and negative impacts on the onset of monsoons. The location of the origin of the cyclone is important for the impact on the monsoon winds. It depends on whether the cyclone is originating in the Arabian Sea or the Bay of Bengal. 

The southwest monsoon in India is influenced by the movement of cyclones in the Bay of Bengal. The monsoon trough, which is a low-pressure area, plays a crucial role in the onset and progression of the monsoon.

When a cyclone is located further north in the Bay of Bengal, the counter-clockwise circulation around the cyclone creates strong southwest winds on its western side. These winds can interact with the monsoon trough and help in pulling it forward. As a result, the southwest winds associated with the cyclone can strengthen the prevailing monsoon winds, aiding in the advancement and onset of the monsoon over the Indian subcontinent.

The onset of the Monsoons: Since the direction of the cyclone movement is anti-clockwise the back winds as a result of the cyclones aid in the onset of the monsoon winds which also flow from southwest to northeast.

When a cyclone is positioned farther north in the Bay of Bengal, the southwest-to-northeast back winds can have a positive impact on the monsoon. These winds help in pulling the monsoon trough forward, aiding in the timely onset of the monsoon season.

1. For example, Cyclone Mocha formed in the Bay of Bengal had a trajectory from northwest to east. Its back winds aided the timely onset of monsoon over the Andaman and Nicobar Islands.

Source:https://www.thehindu.com/sci-tech/energy-and-environment/monsoon-onset-cyclone-biparjoy-climate-change-explained/article66945760.ece

plutus ias current affairs eng med 9th June 2023

PRELIMS QUESTIONS

Q.1 Consider the following statements about the cyclonic back-winds that play a significant role in the onset of the monsoon season:

1. They hinder the onset of the monsoon.
2. They have no impact on the monsoon.
3. They assist in the onset of the monsoon.
4. They cause cyclones to form.

Select the correct answer from the code given below:

1.  1 only
2.  2 only
3.  3 only
4.  None of the above

Answer: (c)

Q.2 Consider the following statements about the initial conditions for the onset of cyclones: 

1. Warm ocean waters above 26℃-27℃.
2. Atmospheric stability with minimal temperature and moisture differences. 
3. Coriolis effect, more pronounced at 5-30 degrees latitude
4. High vertical wind shear.

Select the correct answer from the code given below:

1.  1 only
2.  1 and 2 only
3.  1 and 3 only
4.  All of the above

Answer: (c)

Mains Question

1. Discuss the relationship between cyclone formation and the onset of monsoons with suitable examples.

Mohit Pratap Singh