Climate Change: There is no doubt that El Nino and La Nina are very important natural climate phenomena occurring over the Pacific Ocean. This is because they impact and influence the weather conditions prevalent all over the world. The El Nino is the period that is marked by warmed up or increased temperatures at the surface of the central and eastern Pacific Ocean. Meanwhile, the La Nina period is when the eastern Pacific Ocean surface temperatures are colder than normal. Collectively, these phenomena are called the El Nino Southern Oscillation or ENSO. However, with climate change becoming more and more severe, numerous research have suggested that it could impact the El Nino and La Nina events, causing them to become more extreme and frequent, according to a report in IE.
The report cited a recent paper published in Nature Climate Change. The paper made a note that the future simulated ENSO sea surface temperature variability could be weakened due to the increase of carbon dioxide in the atmosphere. The increase could weaken the intensity of the temperature cycle of ENSO, the paper noted.
Study co-corresponding author Prof Axel Timmermann said that the research showed that these powerful natural phenomena could be silenced by the rampant global warming. Timmermann, who is the director at Pusan National University’s IBS Center for Climate Physics in South Korea, added that they did not yet know what ecological impact such a scenario would have.
The impact was assessed using one of the fastest supercomputers in South Korea – Aleph. The centre said that a single human would take 45 million years to compute the calculation that the supercomputer undertook in a second. One of the authors of the study Dr Sun-Seon Lee said that the supercomputer had been running non-stop for more than a year and completed century-long simulations that cover present-day climate as well as two different levels of global warming.
The team looked at what would happen to ENSO when the level of carbon dioxide doubled and quadrupled. It studied the atmospheric heat and its movement to find out that the ENSO system would collapse. In the future, they found, the El Nino events would most likely lose heat to the atmosphere at a quicker rate due to evaporation of water. It also found that there could be a reduced difference between temperatures in eastern and western tropical Pacific in the future, which could inhibit the temperature extremes that are developed during the ENSO cycle.
Apart from this, the team also looked at the tropical instability waves, and found that they might also weaken, thereby disrupting the La Nina event.
The study said that while year-to-year fluctuations in the temperatures in eastern Pacific equatorial region could weaken due to human impact on the environment, the rainfall extremes related to El Nino and La Nina would continue to increase.