In some regions El Niño causes heavy rains and floods. Photo: humedica
BACKGROUND: El Niño
Torrential rain, severe droughts, escalating fires – the consequences of the climate phenomenon El Niño are disastrous for the affected regions and their inhabitants. Experts figure that all in all this year´s El Niño will turn out much stronger than his precedents. First regional crises affirm this forecast and do not bode well for the coming months.
In our series of topics we provide an insight in the causes and effects of the phenomenon, talk to experts about its impact and set out, which consequences El Niño has for the disaster and development aid of humedica. We start with a background article dealing with the question, what El Niño is all about and how it works.
El Niño – the climate phenomenon put in simple terms
El Niño is a climatic anomaly, which occurs at irregular intervals of several years in the area between the West Coast of South America and Southeast Asia and leads to drastic changes in the global weather. In the Pacific Ocean this phenomenon modifies the circulation of both water and atmosphere – but down to the present day nobody is able to explain why.
In normal years without El-Niño trade winds bring warm water close to the surface from the West coast to Australia and Indonesia. Cool water rich in nutrients rises and takes the place of the carried-away warm water off the Peruvian coasts, which is why the sea there is about seven or eight degrees colder than off the coast of Indonesia. The cold water causes aridity and desertification in West Africa, while heavy monsoon rains go down on the warm sea off Indonesia.
If the El Niño phenomenon makes its appearance like it did this year, the trade winds tone down or sometimes turn even in the opposite direction, wherefore the mass of warm water is carried back to the West African coast.
The consequences of this climatic change are huge: Off the West African coast the nutrient-rich water is lacking, plankton perishes, fish flee to other sea regions or die, too. The sea warming also causes low-pressure areas that carry heavy rainfall and can lead to floods and landslides. That brings about more rain than usual on the North American coast as well.
At the same time El Niño leaves the West Pacific substantially dryer than usual causing crop losses due to droughts and forest fires. But the phenomenon does not only affect the Pacific area.
The modified wind directions in the Pacific region impact also the trade winds of other areas. So the South of Africa endures time and again severe periods of drought, while further North in Somalia and Kenya there are heavy rainfalls.
The current El Niño has already fatal consequences: In Ethiopia, Zimbabwe and Botswana people suffer from the hardest drought since 30 years. Today more than 50 million people are facing serious famine.
As mentioned above, to date no one can explain the causes for El Niño. Some hold solar eruptions responsible for this phenomenon, others blame the climate change and associated global warming and still others think that its appearance is subject to natural fluctuations
Even though the causes for El Niño could not be defined up to date, it is an indisputable fact that the phenomenon exists and that its consequences are fatal.
This article contains information taken from wetteronline.de.