‘Triple dip’ La Nina and its impact on India’s monsoon

Australia’s Bureau of Meteorology (BOM) predicted that a third consecutive event of La Niña could be underway.

What is La Niña?

• La Niña involves the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean coupled with changes in the tropical atmospheric circulation (winds), pressure, and rainfall.
• It usually has the opposite impact on weather and climate as El Niño.
• La Niña is characterized by lower-than-normal air pressureover the western Pacific.
• These low-pressure zones contribute to increased rainfall. 
• La Niña years are associated with above-average trade winds, pushing the warmer waters towards Asia and drawing in cooler than normal water temps to the equatorial pacific. 
• Causes: La Niña is caused by a build-up of cooler-than-normal watersin the tropical Pacific, the area of the Pacific Ocean between the Tropic of Cancer and the Tropic of Capricorn.
  • Unusually strong, eastward-moving trade winds and ocean currents bring this cold water to the surface, a process known as
• Effects:La Niña affects; patterns of rainfall, atmospheric pressure and global atmospheric circulations.

What does a triple La Niña mean?

• A triple La Niña or a ‘triple dip’ La Niña is a rare occurrence, lasting for three years in a row. It has happened only twice since 1950.
• On the contrary, the occurrence of two consecutive La Niña winters in the Northern Hemisphere is common.

Impact on India

• Monsoon: India may experience an extended monsoon lasting up to October due to La Niña.
• Agriculture:La Nina could have negative impacts on Indian agriculture.Farmers will be at risk of losing their standing Kharif crops if it rains during this period.