Rainfall over the southern peninsular region of India has been deficient so far which indicates that the northeast monsoon has remained dull this year.
Key takeaways
Reasons for deficient rainfall this Northeast monsoon
Prevailing La Niña conditions in the Pacific Ocean: La Niña conditions enhance the rainfall associated with the Southwest monsoon, but has a negative impact on rainfall associated with the Northeast monsoon.
Inter Tropical Convective Zone (ITCZ): The current position of the ITCZ has also contributed to the poor rainfall during the ongoing monsoon season. Currently, the ITCZ is located to the north of its normal position.
Important value addition
Northeast monsoon
The Northeast monsoon occurs during October to December.
It is confined to the Southern peninsula.
It is also called the winter monsoon.
Northeast monsoon is important for Tamil Nadu, Puducherry, Karaikal, Yanam, coastal Andhra Pradesh, Kerala, north interior Karnataka, Mahe and Lakshadweep.
Tamil Nadu records about 48% of its annual rainfall during these months, making it the key factor for undertaking agricultural activities.
Some South Asian countries such as Maldives, Sri Lanka and Myanmar, too, record rainfall during October to December.
La Niña
La Niña (Spanish for ‘little girl’) refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, along with changes in the tropical atmospheric circulation.
It usually has the opposite impacts on weather and climate as El Niño, which is the warm phase of the so-called El Niño Southern Oscillation (ENSO).
ITCZ
The ITCZ is a low-pressure belt, whose northward and southward movements along the equator determine the precipitation in the tropics.
