Scientists are still trying to understand how nature's vicious cycle (El Niņo and La Niņa) and volcanic eruptions are causing unusual weather patterns globally. In El Niņo and La Niņa's case, the weather is so variable that it is hard to call any situation normal as the body of warm surface ocean water oscillates (or slashes back and forth) across the Pacific Ocean.
On June 15 1991, the 5770 ft high Mount Pinatubo in the Philippines erupted. During this period, along with volcanic ash, 20 million tonnes of sulphur dioxide was ejected into the stratosphere. This sulphur dioxide when combined with atmospheric water vapour changed into a sulphuric acid "aerosol parasol" - a shield that blocks sun light & lowers global temperature for several years.
The development of TAO (tropical atmosphere / ocean) array of 70 moored buoys to span the equatorial Pacific that monitors the ocean water temperature is an important tool to confirm the periodic arrivals of El Niņo and La Niņa. Using this information, farmers and fishermen in northern Peru made the threat of El Niņo's effects in 1997 - grass grew on land that was usually barren, and farmers raised cattle. Rice and beans could be planted in areas normally too dry to support them; fishermen were able to plan for shrimp harvests in coastal waters, generally too cold for the shell fish.
This early information allows preparation which saves lives. In Peru, construction of storm drains and stockpiling of emergency supplies saved hundred of lives in 1997 and 1998.
Drought caused by El Niņo
A few centuries ago, Isaac Newton, a scientist, proved that light consists of 7 primary colours, red, orange, yellow, green, blue, indigo and violet producing what we call a spectrum.
To prove this, he used a triangular glass prism and a source of light. When light passes through that prism at a certain angle, a spectrum of colours appear at the another side of the prism.
This also happens in the sky, after it rains when the sun is high in the sky. The water droplets in the air act as micro sized prisms to produce a rainbow.
There are many other anomalies of the weather. They include haloes, auroras, sun dogs, mirages, green flashes, volcanic clouds and coronas. Find out more about these anomalies by visiting your school library or even the Internet.