El Nino WORLD AT RISK Learning Intentions: To understand the weather process of the southern Pacific To identify the impacts of ENSO To evaluate the role of development in mitigation of these events

What is the link? http://www.youtube.com/watch?v=SR5VPAqVQBw

Why do we care? Although El Niño events still hold an element of mystery climate scientists now believe that global warming is leading to a increase in magnitude and frequency of El Niño events

Pacific ocean There are close links between the worlds oceans and the atmosphere In the pacific these blow from the east to the west However these winds are not always consistent, which then influences the weather experienced globally

Normal enso Normally these trade winds result in warmer, equatorial waters being pushed towards Indonesia Creating a thermocline meaning that there is an upwelling of colder waters off the coast of S.America

Sea surface temperatures

What does this mean? The cold upwelling in S.America is nutrient rich and supports the Peruvian fishing industry The convection that occurs over Indonesia, not only influences weather locally but plays a role in weather globally

Impacts What would you expect the weather to be like on either side of the Pacific during these conditions?

Shift in the winds During El Niño times the trade winds are weaker allowing the hot pool of water to flood back across the Pacific This has enormous impacts on not only the area but globally

El nino

Signs of an el nino The first signs of an El Niño are: Rise in surface pressure over the Indian Ocean, Indonesia, and Australia Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean Trade winds in the south Pacific weaken or head east Warm air rises near Peru, causing rain in the northern Peruvian deserts Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific. http://www.guardian.co.uk/world/interactive/2004/aug/1 5/elnino

Impacts What impacts do you think an El Niño event could bring? Watch ‘The life and times of El Nino’ and add to your spider diagram IMPACTS OF EL NINO