La Nina

La Nina is an Ocean – Atmospheric phenomenon occurring in the central Pacific Ocean. La Nina is the opposite of “El Nino” and means “Little Girl” in Spanish.

Key Points

  • This complex climate phenomenon occurs as a result of strong Trade winds blowing from Southern America to the Eastern Australian coast.
  • Due to strong trade winds, warm water moves towards the east Australian coast and creates a Low-Pressure Region.
  • It results in the upwelling of cold currents near the South America (Peru) coast, because of which it forms an excellent fishing ground. A high-pressure region is created on the Peru coast.
  • Due to this, atmospheric and oceanic circulation is created between the South American and Australian continents. Showers are seen on the Australian coast while desertification increases on the Peru coast.
  • During La Nina, the temperature of the sea surface across the eastern equatorial part of the central Pacific Ocean will be less than normal by 3 to 5 °C.
  • A La Nina lasts for at least 5 months.
  • It impacts the global climate and weather patterns. This can lead to storms as well as droughts.

IMD forecasts Colder Winter for North and Central India

India Meteorological Department has forecasted colder winter in Northern and Central India, due to the La-Nina phenomenon prevalent over the Pacific Ocean. IMD has forecasted this on the basis of moderate La Nina conditions. The Madhya Maharashtra, Konkan, and the entire eastern southern region will experience a warmer or normal winter season.

ENSO and EL-Nino

ENSO i.e. El Nino–Southern Oscillation is an irregularly periodic variation in the temperatures of the sea surface and winds over the tropical eastern Pacific Ocean. It affects the climate of the tropics and subtropics. El Nino is the warm phase of ENSO. El Nino is accompanied by low air pressure in the eastern Pacific and high air pressure in the western Pacific. Both the phases of ENSO switch in 3 to 7 years.