La Niña is a driving force behind many extreme weather events, and the strength of this system over the Pacific Ocean could double due to climate change, a new study has found. This could create extreme weather events around the world from extreme droughts to powerful storm systems that could cause vast amounts of damage.
Nations in the western Pacific Ocean could experience powerful precipitation events, while much of the United States will be subject to severe and extended droughts, the research reveals. Extreme weather events in the Pacific Ocean currently occur roughly once every 23 years, but new examination shows that frequency of the events could rise to once every 13 years.
La Niña is one phase of the El Niño-Southern Oscillation (Enso) cycle, with the other being the better-known El Niño.
"La Niña episodes represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific... In the tropics, ocean temperature variations in La Niña also tend to be opposite those of El Niño. During a La Niña year, winter temperatures are warmer than normal in the Southeast and cooler than normal in the Northwest," NOAA officials wrote.
La Niña, is a Spanish term, which translates as "little girl." Cool waters during these occurrences run around 5,000 miles across equatorial regions of the Pacific Ocean. The events have been linked to extreme weather events around the world, including blizzards, hurricanes, heat waves, and floods.
"During the 1998-1999 La Niña event, the southwestern United States experienced one of the most severe droughts in history," Wenju Cai from the Commonwealth Scientific and Industrial Research Organization in Australia said.
During that single La Niña event, floods covered more than half of Bangladesh, flooding and landslides occurred in Venezuela that killed between 25,000 and 50,000 people. More than 200 million people were driven from their homes, and thousands of residents killed by floods and storms in China. Over 11,000 people were also killed in Honduras and Nicaragua by Hurricane Mitch.
Climate change is also likely to drive extreme weather events from an average of once every 20 years to once a decade, Cai and his team determined in 2014. Roughly 75 of extreme La Niña events occur immediately following a severe El Niño phase.
Temperature differences in regions of the Pacific will drive stronger La Niña events, the study found.
"The implications are profound. It means affected regions will experience opposite extremes from one year to the next," Cai told the press.
Study of La Niña and how the system can be effected by climate change was detailed in the journal Nature Climate Change.
