Scientists blame these two ‘children’ for drastic changes in our weather patterns
Over the years, we have come to accept that the change in our weather is the fault of either an El Niño, or a La Niña – this is over and above of course, the impact due to climate change and global warming.
So, who are these naughty children and why are they messing with our weather patterns?
El Niño was originally named El Niño de Navidad by Peruvian fishermen in the 1600s to describe a warm southward coastal current that occasionally developed around the Christmas season. El Niño is Spanish for “the Christ Child.”
La Niña means The Little Girl in Spanish. La Niña is also sometimes called El Viejo, anti-El Niño, or simply “a cold event.”
Meet El Niño
Well for a start, an El Niño is nothing new. El Niño was originally named El Niño de Navidad by Peruvian fishermen in the 1600s to describe a warm southward coastal current, that occasionally developed around the Christmas season.
Climate records of El Niño go back millions of years, with evidence of the cycle found in ice cores, deep sea muds, coral, caves and tree rings.
During an El Niño, the trade winds weaken in the central and western Pacific. Surface water temperatures off South America warm up, because there is less upwelling of the cold water from below to cool the surface. The clouds and rainstorms associated with warm ocean waters also shift toward the east.
The warm waters release so much energy into the atmosphere that weather changes all over the planet. In Africa, it often brings excessive rains to the east, while the southern and eastern areas experience drought.
Forecasters declare an official El Niño when they see both ocean temperatures and rainfall from storms veer to the east. Experts also look for prevailing trade winds to weaken and even reverse direction during the El Niño climate phenomenon.
These changes set up a feedback loop between the atmosphere and the ocean that boosts El Niño conditions. Scientists do not yet understand in detail what triggers an El Niño cycle. Not all El Niños are the same, nor do the atmosphere and ocean always follow the same patterns from one El Niño to another.
According to weather scientists there is no single cause of an El Niño. This is one of the reasons why they can’t always accurately predict them. There is some predictability in the common features that arise with El Nino, which is why weathermen can make forecasts of it. But it won’t be the same every time.
El Niños occur every three to five years but may come as frequently as every two years or as rarely as every seven years.
Meet La Niña
La Niña is also sometimes called El Viejo, anti-El Niño, or simply “a cold event.” La Niña episodes represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific and tend to be opposite to those of El Niño impacts.
How El Niños effect South Africa and fuels unwanted wildfires
Typically, El Niños occur more frequently than La Niñas. Each event usually lasts nine to 12 months. They often reach peak strength between December and January, and then decay by May of the following year.
According to recent reports from the South African Weather Bureau, although the southern part of Africa generally receives below-normal rainfall during El Niño years and La Niña usually brings normal or above-normal rainfall, this cannot be accepted as a rule.
According to South African weather bureau, the 1997-98 El Niño was the strongest on record, but not all South Africa received below-normal rainfall. Earlier this year the Weather Service reported that prospects of an El Niño weather pattern forming has risen significantly. In a Reuters report, writer Ed Stoddard explained that El Niño usually brings drier weather to Southern Africa.
According to Kishugu co-founder and CEO Chris du Bruno Austin, this creates ideal weather conditions to fuel unwanted wildfires. Last year El Niño conditions were the primary cause of the drought that hit harvests, slowed economic growth and created an ideal environment for wildfire.
According to reports, Aid agencies have warned that its return could be catastrophic for areas such as southern Madagascar, which has been experiencing chronic food shortages.
Kishugu deals with the El Niño child
“Although there is nothing we can do about the fire-friendly weather that the El Niño brings – such as drought, berg winds and temepratures that favour ignition, we can be prepared to reduce the damage that unwanted wildfire causes,” said Austin.
“At Kishugu we have proved repeatedly that the implementation of our Integrated Fire Management strategies is the best defence against the weather that an El Niño delivers.”
*With acknowledgement to the National Ocean Service (National Oceanic and Atmospheric Administration, US department of Commerce), The National Centre for Environmental Information and the SA Weather Bureau.