Syllabus:

GS-1: Salient features of the World’s Physical Geography; Important Geophysical phenomena

Context:

The India Meteorological Department (IMD) announced that the southwest monsoon has arrived over parts of the Bay of Bengal and Andaman Sea at least a week before its scheduled arrival time.

More on the News

  • This year marks the region’s earliest monsoon onset in seven years, preceding IMD’s normal date of May 21 for the South Andaman Sea and Port Blair.

Monsoon in India

  • Monsoon refers to the seasonal reversal in the direction of winds and the associated rainfall. This word is derived from the Arabic word “Mausim”.
  • Southwest Monsoon:
  • It occurs from June to September. It hits Kerala on the southwestern coast and then proceeds across the country.
  • This is the main monsoon impacting India, bringing relief from the heat and significantly supporting the ecosystem, economy, and kharif crop cultivation.
  • Over 70 percent of India’s annual rainfall occurs between June and September, with a Long Period Average of 880 mm.
  • Northeast Monsoon:
  • It occurs from October to December and affects peninsular India. It is not as intense as the southwest monsoon but is crucial for the growth of rabi crops.
  • It is crucial for Tamil Nadu, Kerala, Puducherry, Karaikal, coastal Andhra Pradesh, Rayalaseema, and Yanam. Tamil Nadu gets about 48% (443.3 mm) of its annual rainfall from October to December, which is vital for rabi crops.
  • It is also known as the winter monsoon, retreating monsoon, or reverse monsoon.

Effects of climate change on Changing Rain Pattern in India due to Climate Change

  • Traditionally drier regions like Rajasthan, Gujarat, Konkan, central Maharashtra, and parts of Tamil Nadu saw over a 30% rise in southwest monsoon rainfall compared to the 1981–2011 average.
  • Traditionally high rainfall regions like Assam and Meghalaya experienced a decline in monsoon precipitation.
  • Southwest monsoon rainfall increased in 55% of India’s tehsils, driven mainly by short, intense downpours that often lead to flash floods.
  • During the southwest monsoon in India, wet extremes account for an increasing share of total seasonal rainfall.
  • The retreating monsoon rainfall spiked by more than 10% in approximately 80% of tehsils in Tamil Nadu, 44% in Telangana, and 39% in Andhra Pradesh.
Shares: