This picture of El Nino weather pattern is courtesy of NASA. The El Nino effect can be seen in the white around Central America.
What Is El Nino & La Nina Weather Pattern?
The El Nino effect weather pattern originates in the eastern Pacific Ocean off the coast of South America, raises the water temperature greater than 0.5°C and initiates a process of changing weather patterns all over the world. El Nino & La Nina works with the Southern Oscillation weather phenomena and often referred to collectively as ENSO for convenience.
La Nina is the opposite of El Nino and creates a cooling effect in the ocean, but does not occur as often and like its big brother La Nina changes weather patterns globally.
What is the definition of El Nino & La Nina, where did the meaning originate?
South American fisherman were the first to coin the term “El Nino” meaning technically “the boy” and colloquially as “the Christ child” for the time of year when the weather pattern is most prevalent. La Nina means “the girl”, the opposite of El Nino.
What are the effects of El Nino & La Nina?
El Nino is known for causing or increasing droughts in Australia, North & South America and parts of Africa, brings warmer winters for North America, and inhibits trade winds that bring nutrient rich cooler water to come to the surface and flow along currents. The lack of nutrient rich cooler waters means less food for fish, results in lower reproduction, changes their migratory patterns and even fish kills are known to happen. El Nino years have coincided with countless fishery collapses in South America and beyond. In fact, one particularly bad El Nino year it was resposible for killing more than 15% of the worlds coral reefs because of the change in water temperatures and the lack of flowwing nutrients.
La Nina brings stormier, wetter weather. Monsoons, flooding, active typhoon and hurricane seasons and earlier, heavier snowfall and lower temperatures in northern countries. La Nina is part of what makes our planet active, weather wise. But, La Nina’s have been becoming more few and far between in recent years which brings us to our next section.
This YouTube Video gives some great information on the effects of El Nino.
What causes El Nino & La Nina and how often do the occur?
Scientist don’t have an answer as to the cuase of El Nino’s and La Nina’s. But what is noticeable is the coincidental increase in the global warming phenomenon. Is this nurture or nature; with the increase of El Nino’s and the diminishing of La Nina’s, is human activities the cause of the increased El Nino’s? Or, are we just going through a normal long term warming trend that is caused by El nino? Scientists are busy gathering data and trying to put all the pieces of a very big puzzle into place. Also, depending on which side of the fence you sit on, there is no shortage of opinions.
El Nino’s occur approximately every 3 to 5 years and can last from 6 months 2 over 2 years. Conversely La Nina’s occur in between the El Nino years and don’t last as long. As mentioned earlier going into the future these numbers could change, and the trend is for more frequent and longer lasting El Ninos.
ENSO was such a great discovery for weather meteorologists in that they now can provide much more detailed and longer range weather forecasts.
Darshan Montgomery and FriendlyForecast.com providing a great Victoria BC Weather forecast.