El nino/la nina and a normal year

Trade winds blow towards the equator and the warmer water of the western pacific.

The trade winds patterns are disrupted

Here the warmer water heats the air above causing convectional uplift, creatng low pressure weather conditions and rainfall over south east asia

In the East Pacific off the coast of Peru, the conditions are dry as the air returns and sinks here, creating the walker loop.

The trade winds either die or blow in the opposite direction

The pressure of the trade winds results in sea levels in Australasia being 50cm higher than in peru and sea temps 8C higher

The air movement also enables the winds to pull up water along the east coast of south america

the air circulation loop is reversed

On the east coast of south america there is a shallow warm upper layer overlying the deep cold layer of the ocean the boundary between these layers is the thermocline

The thermocline causes an upwelling of cold water bringing nutrients from the ocean bottom and producing optimum fishing conditions off the coast of peru

Trade winds in the western pacific die or blow in the opposite direction

it's like an exxagerated normal year

the water that is normally piled up in the west moves back to the east so that the sea level on the peruvian coast rises 30m and conditions are calmer across the whole pacific ocean.

The air circulation loop is reversed so that air sinks in the western pacific bringing drought to countries in that region

extremely strong trade winds

Air rises in the eastern pacific causing convectional rainfall- sometimes flooding in coastal areas in south america

The change in location of air distorts the jet streams causing world wide teleconnections

An exaggerated normal year with a very strong walker loop

There are extremely strong trade winds pushing warmer water westwards and raising the sea level by up to a meter higher in indonesia and the phillipines

causes landslides in south america

Deep low pressure develops over south east asia causing heavy rain on account of the pacific there is a strong upwelling of cold water off the coast of peru

The higher than average pressure that occurs heer causes severe drought in the semi-arid areas of peru and northern chile

heavy rainfall in europe and flooding

The see sawing of atmospheric pressure between the easterm pacific and the indo australian area is called the southern oscillation

Drought in indonesia, australia and malaysia - west

many people die of extreme heat caused =east

mild winters in n.usa and w.canada -west

demise of pevurian fish catches - east

reduced hurricane season -west

increased rain in southern usa states

Increased galapago iguana mortality rate -west

lots of hurricanes in n america - west

heavy rainfall in europe in the spring causing flooding-east

high rain in s america leading to landslides in the andes - east