Why in news?
A study by independent meteorologists has predicted a decline in rainfall over the Central Indian region.
What is the finding?
- Low Pressure Systems (LPS) usually bring rain to this area.
- But there is a declining trend in the number of these Low Pressure Systems (LPS).
- The region will witness a 45% decline in the frequency of LPS activity.
- About 50 years from now, the monsoon over central Indian region is expected to reduce.
- This could result in lesser rainfall in this heavily rain-fed agrarian belt.
- This is expected to be realised during the decades spanning between 2065 and 2095.
- The study also highlights a 10% increase in the instances of LPS forming over land.
- This would eventually lead to extreme rainfall over the North Indian plains.
How do LPSs work?
- Low Pressure Systems (LPS) originate in the Bay of Bengal.
- They travel landwards in a southeast-northwest direction.
- It crosses Odisha, Andhra Pradesh, Telangana, Chhattisgarh, Jharkhand, Madhya Pradesh, Maharashtra and Uttar Pradesh.
- This region is known as the core monsoon zone.
- Most LPS pass by this region during the June to September monsoon season.
- This makes it a very crucial region to understand the monsoon.
- A new test-bed facility is being set up on the outskirts of Bhopal to study these key rain-bearing systems.
Why is the decline?
- One of the main reasons for decrease in rainfall could be the large-scale decrease in the moist westerly winds.
- These winds, called monsoon circulations, travel from the Arabian Sea along India’s west coast onto the mainland.
- In addition, these are observed to have shifted northwards from their normal track during their forward propagation.
- Climate change effect on the monsoon, especially over the core monsoon zone, is seen as inevitable.
- With the rise in global temperature, the atmosphere would have a much higher moisture holding capacity.
- But at a certain point this capacity would collapse, leading to extreme rainfall events and absence of consistent rainfall.
- Extreme rainfall events are already found to be increasing in recent years.
Source: Indian Express
