El Niño-Southern Oscillation (ENSO) is a climate phenomenon occurring every 2–7 years in the tropical Pacific Ocean, associated with changes in air pressure east to west.
During El Niño events equatorial trade winds blowing west weaken, causing changes in air pressure and wind speed that move warm surface water eastward from the western Pacific to coastal South America. This results in a deeper thermocline (the depth at which sea temperature rapidly changes) that prevents the normal upwelling of cooler, nutrient-rich waters, having devastating impacts on marine food chains, as well as local communities reliant upon the fishing industry.
It also brings heavier and prolonged rainfall to South America, increasing the threat of flooding, while in Australia and Indonesia there is drought, posing hazards for water supply and irrigation for agriculture. During La Niña events, all off these conditions reverse.
New research published in Geophysical Research Letters suggests that ENSO is likely to be strongly impacted by continental deforestation (purposeful felling trees), specifically that occurring in the “Maritime Continent”—the region between the Indian and Pacific Oceans that includes the archipelagos of Indonesia, Borneo, New Guinea, Philippine Islands and Malay Peninsula.
Land use changes such as deforestation reduce evapotranspiration and cause alterations to surface albedo (the amount of sunlight reflected by Earth’s surface) that ultimately warms the ambient environment. This further impacts land-atmosphere-ocean interactions to modify local climate.
2023-11-07 19:41:15
Post from phys.org
