The Drastic Weather Phenomenon: El Nino
- Science
Ama perera
- 10 minutes read
What is El Nino?
Let’s go for the Introduction
El Nino is a climate pattern that describes unusual warming of surface waters in the eastern equatorial Pacific Ocean. Moreover, Trade Winds and Atmosphere are impacted by El Nino. For much detail, El Nino is the “warm phase” of a larger phenomenon called El Nino-Southern Oscillation(ENSO).
Is El Nino dangerous? Now let’s discuss about the Causes and Effects of El Nino events in Southern Pacific Ocean
In normal conditions,
Cold water, rich in nutrients flows in northerly direction along the west coast of South America. This is accompanied by a upwelling of nutrients caused by winds blowing from South. As a result of this, water will be having high productivity with a large number of anchovies and sardines feeding in plankton rich water. The higher productivity supports substantial fisheries industry and many species of sea birds and other organisms. Here further discussion about the change in the weather patterns in Pacific Ocean due to El Nino which occur every 3 to 5 years,
● The prevailing trade winds stop blowing in their normal pattern from the east.
● Warm Equatorial water is blown by abnormal winds from the West.
As a result, pressure gradients in the West and East Pacific Ocean are reversed causing a reversal of wind direction and equatorial currents.
This creates a large area of warm water….
● In addition to this effect, Upwelling stops and so the supply of nutrients to surface water is reduced.
● Increase in temperature results in death of many Cold water species and coupled with lack of nutrients, this causes the primary production to decrease.
●This affects higher trophic levels in food chains and food webs with the consequent collapse of commercial fish stocks.
● Also this effect causes to increase runoff (flooding)
● The salinity (salt level) in the ocean decreases as well.
El Nino often brings torrential rains in the north of the mountainous Latin American nations along with a high risk of mudslides. Also it can cause extended droughts in other parts of South America, Indonesia, Australia and Africa
Below shows some consequences of El Nino
Climatologists determined that El Nino occurs simultaneously with Southern Oscillation. Southern Oscillation is a change in air pressure over the tropical Pacific Ocean
How to determine the arrival of El Nino?
El Nino events are indicated by sea surface temperature increases of more than 0.9° Fahrenheit for at least five successive 3 months seasons. There are several means used to detect El Nino such as Satellites, Moored ATLAS and PROTEUS buoys, drifting buoys and sea level analysis.
Future Predictions by researchers…..
A peak in late 2020 could push the average annual temperature rise to a new record in 2021…
Illustration on how the temperature has changed through the years
In order to study seasonal to international variability and predictability around the globe with an emphasis on ENSO, the TOGO Program was designed.
Be on the watch for new researches on whether there will be a greater danger due to El Nino
AMA PERERA
