‘Double-Dip’, La Nina forms for second year in a row: NOAA

Context

A La Nina system has formed for the second year in a row, according to the Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA).

Key-highlights

• The latest La Nina is expected to last through the early spring of 2022 (February).
• Previous La Ninas occurred during the winter of 2020-2021 and 2017-2018. An El Nino developed in 2018-2019.

Double-dip

• Two La Ninas happening one after the other (with a transition through ENSO neutral conditions in between) is not uncommon.
• It is usually referred to as a ‘double-dip’. In 2020, La Nina developed during the month of August and then dissipated in April 2021 as ENSO-neutral conditions returned, the statement said.

Understanding the geographic phenomenon

• La Nina (means ‘little girl’ in Spanish) is a natural ocean-atmospheric phenomenon.
• It is marked by cooler-than-average sea surface temperatures across the central and eastern Pacific Ocean near the equator.
• El Nino: It is the opposite of El Nino(meaning ‘little boy’), that is marked by warmer-than-average sea surface temperatures across the central and eastern Pacific Ocean near the equator.
• Both, La Nina and El Nino are part of the El Nino Southern Oscillation (ENSO) cycle.
• ENSO is characterized by opposing warm and cool phases of oceanic and atmospheric conditions in the tropical Pacific Ocean.
• El Nino usually causes a decrease in precipitation and has been found to cause drought-likeconditions in India. On the other hand, La Nina causes an increase in precipitation. It also causes formation of low-pressure areas.