The Pacific waters off the coast of South America are currently experiencing an unusual “coastal El Niño”, according to biological oceanographer Francisco Chavez of the Monterey Bay Aquarium Research Institute. This event is not linked to the larger El Niño phenomenon which has global climate implications but is instead a band of warm water isolated to the region. Meanwhile, models have suggested that there is a 62% chance of a classical El Niño developing by June or July, with a possible four in 10 chance of a strong El Niño event. However, forecasting such an event remains challenging due to complex atmospheric dynamics and a high level of uncertainty.
El Niño events can have significant consequences for global weather patterns. For example, less hurricane activity typically occurs in the Atlantic when El Niño is active in the Pacific. However, the wider impact on precipitation is unclear, with Peru potentially experiencing higher levels of rainfall but the Amazon rainforest at risk of devastating drought. Additionally, the warming of the Pacific could play a significant role in raising global temperatures, with 2023 potentially becoming a record-warm year.
Heat in the ocean can also have significant consequences for marine health, with warmer waters becoming less biologically productive. Corals, in particular, are sensitive to heat and can bleach in response, releasing their symbiotic algae that provide them with energy. Furthermore, the ocean’s natural circulation, influenced in part by temperature, plays an important role in supporting the food chain. Upwelling, which brings cold water to the surface, helps to fertilize phytoplankton, which in turn is a critical food source for zooplankton. Should the ocean stratify due to high surface temperatures, it may become more difficult to break up the necessary nutrients for these creatures to survive, ultimately leading to a less fertile ocean.
It is clear that the potential impacts of future El Niño events are wide-ranging and complex, and as such, demand further attention and research to help mitigate the potential negative effects.
