El Niño is an abnormal heating up of the waters of the Pacific Ocean in equatorial regions. El Niño means "the Christ Child", a name given to it by Peruvian fishermen when, due to this phenomenon, they saw all the fish disappear from the coast of Peru at around Christmas time every 3 to 7 years.

This heating up of the ocean waters has an impact on air pressure in certain regions. For example, it has been shown that during El Niño droughts occur in Southeast Africa and Northern Brazil, while the west coast of South America experiences excessive rainfall and flooding. The year after El Niño usually brings La Niña, with unusually cold sea temperatures and the opposite effects.

The extensive forest fires in Indonesia, the floods in China and other natural disasters are all likely to be the result of El Niño. In East Africa too, the climate seems to be influenced by El Niño/Southern Oscillation.

With the help of satellite images we are studying abnormal fluctuations in rainfall and plant growth to see whether these are always associated with the appearance of an ENSO phenomenon.

The area around Lake Tanganyika is very sensitive to climatic change. Recent fluctuations in climate are being studied by means of satellite pictures and meteorological measurements, while phenomena produced over the last 1000 years are being studied by analysing the sediments found on the lake bed. The main aim is to understand what effect a climatic phenomenon such as El Niño/Southern Oscillation (ENSO) has on the lake and its environment. ENSO is a disturbance of the ocean and the atmosphere which occurs regularly (every 3 to 7 years) in the Pacific Ocean, but the effects of which are felt all over the world, also in East Africa.