The India Meteorological Department (IMD) forecasted above-normal rain in the upcoming monsoon season in India, with “favourable” La Nina conditions expected to set in by August-September.
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Key aspects |
El Nino |
La Nina |
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Meaning |
It is a loose translation of “little boy” or “Christ child” in Spanish. |
It is called as “Little girl” in Spanish which is the opposite of El Niño. |
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About |
It is the warming of sea waters in Central-east Equatorial Pacific that occurs every few years (Warm phase off the coast of Peru).
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It sees cooler than average sea surface temperatures in the equatorial Pacific region (Cool phase).
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Trade winds |
It weakens in the western Pacific which cause warmer waters in the East. |
It becomes stronger than normal ans cause warmer waters in the west. |
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Sea surface temperature |
It increases across the Eastern Pacific by 6-8°C. |
It reduces across the Eastern Pacific by 3-5°C. |
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Impact |
It disrupts normal upwelling, reducing the rise of cold, nutrient-rich water from the ocean depths. |
It enhances upwelling, bringing cold, and nutrient-rich water to the surface near South America. |
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Impact on India |
It has the impact of suppressing monsoon rainfall, can cause droughts, adversely affecting agriculture and water supply. |
It is associated with good rainfall during the monsoon season. |
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Frequency |
It occurs every 3-7 years |
It occurs half the amount of time El Nino events do. |
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Fish population |
Reduced upwelling of deep nutrient rich waters leads to reduction in fish populations along South America coast. |
Enhanced upwelling of nutrient rich waters increasing fish populations along South American coast. |
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Recent ENSO trends |
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Indian Metrological Department |
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