Glossary
El Niño
The warm phase of ENSO, characterized by a significant warming of the Pacific Ocean surface waters between South America and Papua New Guinea, disrupting normal weather patterns.
Example:
During an El Niño year, the normally dry Atacama Desert in Chile might experience unusual rainfall, leading to a rare bloom of flowers.
El Niño-Southern Oscillation (ENSO)
A natural climate pattern involving a giant seesaw of ocean temperatures and atmospheric pressure in the tropical Pacific, with El Niño and La Niña as its opposite phases.
Example:
Understanding the El Niño-Southern Oscillation helps scientists predict global weather anomalies, like why California might experience heavy rainfall one year and severe drought a few years later.
La Niña
The cool phase of ENSO, involving a cooling of the Pacific Ocean surface waters in the same region as El Niño, often leading to opposite weather effects.
Example:
A strong La Niña event might bring unusually cold and wet conditions to the Pacific Northwest of the United States, increasing snowpack in the mountains.
Migration Changes
Alterations in the seasonal movement patterns of animals, particularly birds, influenced by ENSO events affecting food availability or habitat conditions.
Example:
An unusually warm El Niño winter could disrupt the typical migration changes of monarch butterflies, affecting their overwintering sites.
Ocean Heat Capacity
The ocean's ability to absorb and store heat, which can decrease during El Niño, potentially contributing to global warming.
Example:
When the ocean heat capacity is reduced during an El Niño, more heat remains in the atmosphere, potentially exacerbating global temperature increases.
Precipitation Changes
Shifts in rainfall patterns caused by ENSO events, leading to increased risks of floods in some areas and droughts in others globally.
Example:
During El Niño, some regions like the Amazon rainforest might experience severe droughts, while others, like parts of the US, see increased precipitation changes and flooding.
Species Relocation
The forced movement of animal or plant species to new habitats due to rapid climate changes, such as those induced by ENSO events.
Example:
As ocean temperatures shift during El Niño, certain fish species might undergo species relocation, moving to cooler waters, which impacts local fisheries.
Thermocline
The layer in the ocean where a sharp temperature drop occurs, which deepens during El Niño and becomes shallower during La Niña.
Example:
A deeper thermocline during El Niño means less nutrient-rich cold water reaches the surface, impacting marine life like anchovy populations off Peru.
Trade Winds
Prevailing winds that blow from east to west across the tropical Pacific, which weaken during El Niño and strengthen during La Niña, driving the ENSO cycle.
Example:
Stronger trade winds during a La Niña event can push warm surface water far to the west, leading to cooler ocean temperatures near South America.
Upwelling
The process where colder, deeper, nutrient-rich water rises to the surface, typically occurring along coasts and enhanced during La Niña.
Example:
Increased upwelling off the coast of California during a La Niña year can lead to a boom in phytoplankton, supporting larger fish populations.