The India Meteorological Department (IMD) had forecast below normal Northeast monsoon over Tamil Nadu and normal rainfall over the southern peninsula for the current season.
- This year, the Southwest monsoon withdrew completely from the country on October 28, with a delay of a fortnight. On the same day, the IMD declared the onset of the Northeast monsoon over peninsular India.
- IMD have linked it to the prevailing La Niña conditions in the Pacific Ocean.
- The current position of the Inter Tropical Convective Zone (ITCZ) has also contributed to the poor rainfall during the ongoing monsoon season.
What is Northeast monsoon?
- The Northeast monsoon, also called the winter monsoon, occurs during October to December, and is a comparatively small-scale monsoon, which is confined to the Southern peninsula.
- The rainfall associated with the Northeast monsoon is important for Tamil Nadu, Puducherry, Karaikal, Yanam, coastal Andhra Pradesh, Kerala, north interior Karnataka, Mahe and Lakshadweep.
- Some South Asian countries such as Maldives, Sri Lanka and Myanmar, too, record rainfall during October to December.
- About 75 per cent of the country’s annual rainfall is received from the Southwest monsoon and rest from the Northeast monsoon.
What is La Nina?
- La Niña (Spanish for ‘little girl’) is an abnormal cooling of Pacific surface waters.
- Together, the El Niño and La Niña phenomena are termed as El Niño Southern Oscillation (ENSO).
- While La Niña conditions enhance the rainfall associated with the Southwest monsoon, it has a negative impact on rainfall associated with the Northeast monsoon.
Inter Tropical Convective Zone (ITCZ)
- The ITCZ is a low-pressure belt, whose northward and southward movements along the equator determine the precipitation in the tropics.
- Currently, the ITCZ is located to the north of its normal position.
(Source: Indian Express)
