El Nino and southern Oscillation (ENSO)
ENSO (el Niño and the southern oscillation) Oscillation of ocean temperature/Fluctuation of ocean temperature Usually occurs in the southern hemisphere Equatorial Pacific Ocean Occurs around Christmas time Warm water Impact weather conditions around the world
“Normal” “Neutral phase” “ENSO” Trade winds blow east to west Pushes warm water towards Asia (India, Indonesia) Warm air rises Monsson season The warm water being pushed away from central and south America is replaced by cold water…. “upwelling” Upwelling waters carries nutrients Phytoplankton like nutrients Zooplankton like phytoplankton Fish like zooplankton Bigger fish like fish People like fish
“Normal” “Neutral phase” Warm air rises and cools Rain This air travels east and up reaching the troposphere Air is cool and dry and sink over Peru
Normal
Not normal-El Niño event Warm phase of ENSO Winds are not strong enough to push the warm water to the west Warm waters slow move to the eastern side of the pacific Upwelling of cold nutrient rich waters does not occur Rain patterns change Sea levels rise-warm water expands Floods in central/south America (Peru) Droughts in Indonesia, India Where does it occur? Tropical Pacific ocean Equatorial pacific ocean What is it Development of warm ocean waters Change/moving of rain fall patterns Impact global weather and climate Trade winds weaken Atmospheric pressure weakens
Each El Nino event is different Usually experience warmer global temperatures during el nino years
El Niño
La nina Similar to normal or neutral phase Cold phase of ENSO Trade winds are strong Cold ocean current
El Nino changes climate What are the implications? Wetter conditions increase the transmission of diseases Flooding leads to more mosquitos which transmit diseases like malaria, dengue fever, yellow fever, zika Sanitation problems-water sources are contaminated with raw sewage which can lead to the spread of cholera, dysentery and giardia
El Nino changes climate What are the implications? Warmer water promotes transmission of diseases Bacteria growth Increase insect breeding Habitat destruction-loss of biodiversity Coral bleaching-loss of biodiversity No upwelling-loss of food, disruption of food web Disrupt migration patterns-disruption of food web
El nino changes climate What are the implications? Warmer land temperatures increase breeding seasons for insects (mosquitos)-vectors for disease transmission increase in area/range of insects high populations of insects because they are not killed off by colder weather Species are unable to adapt and starve/die off Habitat destruction
El nino changes climate What are the implications? Drier air Stagnant water= breeding ground for insects/mosquitos One of the largest Dengue fever outbreaks was during an unusually dry season
El nino changes climate What are the implications? Drought Less freshwater Concentrated pollutants in the little water available Increase in diarrheal diseases-cholera-leads to dehydration leads to death Increase of fires-habitat destruction-loss of biodiversity Decrease of food production-decrease in available food-organisms starve
Increase in rain fall Flooding-plants cant grow-loss of food source Erosion-habitat destruction Mudslides-habitat destruction Increase in storms-increase of rain fall-flooding-habitat destruction