Previous studies based on the climate models participating in the Coupled Model Intercomparison Project (CMIP) have suggested an increase in the frequency of extreme El Niño events in the 21st Century in response to increasing greenhouse gases. Several studies have attributed these shifts in El Niño frequency and amplitude to the projected changes in the tropical Pacific mean state. In a new study published in Nature Communications, a team of scientists led by Hosmay Lopez at NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) investigated the seasonal evolution of El Niño events in the 21st century. The highlight of the major findings is that El Niño is projected to grow at a faster rate, and persist longer over the eastern and far eastern Pacific. These changes are attributed to significant changes in the tropical Pacific mean state in boreal spring and summer, dominant atmosphere-ocean feedback processes, and an increase in stochastic westerly wind burst forcings in the western equatorial Pacific. An important implication of these findings is that future El Niño events may have stronger and more persistent remote impacts over the globe via atmospheric teleconnections, especially during the onset and decay phases in boreal spring and summer.
Image Credit: https://sealevel.jpl.nasa.gov/data/el-nino-la-nina-watch-and-pdo/el-nino-2015/
Lopez, H., Lee, SK., Kim, D., Wittenberg, AT & Yeh, SW. (2022). Projections of faster onset and slower decay of El Niño in the 21st century. Nature Communications 13, 1915. https://doi.org/10.1038/s41467-022-29519-7
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