The changing climate has been a persistent topic of research in recent years, with many scientists seeking to understand the potential impacts of our warming planet. Recent research has indicated that climate change may have greater implications than we initially thought – it could potentially cause intensified El Niño and La Niña events. These findings were achieved through one of South Korea’s fastest supercomputers, Aleph.
The Findings – Key Insights
Based on the simulations run on the Aleph supercomputer, increasing levels of atmospheric carbon dioxide could weaken future sea surface temperature variability during the El Niño-Southern Oscillation (ENSO) cycle. This implies that the heat from future El Niño events will be lost more rapidly due to the accelerated evaporation of water vapor. Other projected changes include a decreased temperature difference between the eastern and western tropical Pacific, which may hinder the development of temperature extremes during the ENSO cycle. The simulations also suggest a future weakening of Tropical Instability Waves (TIWs), a key feature influencing temperature variability in the equatorial Pacific and Atlantic Ocean regions, potentially disrupting La Niña events.
Understanding ENSO: El Niño and the Southern Oscillation
El Niño and the Southern Oscillation, collectively known as ENSO, denote periodic fluctuations in sea surface temperature (El Niño) and the air pressure of the overlying atmosphere (Southern Oscillation) across the equatorial Pacific Ocean. They manifest as complex weather patterns triggered by variations in ocean temperatures in the Equatorial Pacific Region. Both El Niño and La Niña phenomenons typically last nine to 12 months, though some prolonged events can persist for years.
About El Niño
El Niño is a climate pattern characterized by the anomalous warming of surface waters in the eastern tropical Pacific Ocean. Serving as the “warm phase” of the ENSO cycle, El Niño tends to occur more frequently than La Niña. The warmer Pacific waters linked to El Niño cause a southward shift in the Pacific jet stream, causing varying climate impacts across different regions. While the northern US and Canada experience drier and warmer conditions, the US Gulf Coast and Southeast face increased rainfall and flooding.
Impact of El Niño
The impact of El Niño extends beyond weather patterns to affect marine life off the Pacific coast. Under normal conditions, upwelling brings cold, nutrient-rich water from ocean depths to the surface. During El Niño events, this upwelling weakens or halts, reducing the supply of nutrients necessary for phytoplankton growth. This affects fish that feed on phytoplankton and, subsequently, species higher up the food chain. Warmer waters may also draw tropical species usually found in warmer regions into colder habitats.
About La Niña
La Niña is the “cool phase” of the ENSO cycle and is characterized by the unusual cooling of the tropical eastern Pacific. Unlike El Niño events, which usually last no more than a year, La Niña episodes can last between one and three years.
Impact of La Niña
The effects of La Niña are felt strongly along the west coast of the Americas, where increased upwelling occurs, bringing cold, nutrient-rich water to the surface. This phenomenon generally benefits the western South American fishing industry. A more severe hurricane season may occur during a La Niña event, as it causes the jet stream to move northward and weaken over the eastern Pacific. Consequently, the South American countries of Peru and Ecuador experience drought, and areas in the Western Pacific, Indian Ocean, and off the Somali coast witness increased temperatures. La Niña events can also lead to extreme flooding in Australia.
