• The Northeast monsoon has remained subdued this year. Rainfall over the Southern peninsular region has been deficient so far. The reason is a prevalent La Niña condition, along with a low pressure belt that is currently lying to the north of its normal position.
• India receives rainfall during two seasons. About 75 per cent of the country’s annual rainfall is received from the Southwest monsoon between June and September.
• The Northeast monsoon, on the other hand, occurs during October to December, and is a comparatively small-scale monsoon, which is confined to the Southern peninsula.
• Also called the winter monsoon, 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.
How is La Niña linked with the Northeast monsoon?
• While La Niña conditions enhance the rainfall associated with the Southwest monsoon, it has a negative impact on rainfall associated with the Northeast monsoon.
• during La Niña years, the synoptic systems — low pressure or cyclones — formed in the Bay of Bengal remain significantly to the north of their normal position.
• Besides, instead of moving westwards, these systems recurve. As they lie to the north of their normal position, not much rainfall occurs over southern regions like Tamil Nadu.
Mains Paper 1: Geography
Prelims level: Northeast monsoon
Mains level: How is La Niña linked with the Northeast monsoon?