What is responsible for the strong observed asymmetry in teleconnections between El Niño and La Niña?

摘要: A large asymmetric component (El Nino + La Nina) of El Nino–Southern Oscillation (ENSO)-related teleconnections over North America is found during 1984–2009 that comparable in strength to the commonly studied symmetric Nino − La Nina). Climate reforecasts spanning this period are diagnosed order understand processes responsible for observed asymmetry. It confirmed an indeed a fundamental property atmospheric responses recent ENSO forcing. Each and every composite 16-member reforecast ensemble has appreciable asymmetry tropical Pacific rainfall, upper tropospheric Pacific-North American circulation patterns, contiguous U.S. surface temperatures. There considerable sampling variability magnitude among individual composites. We argue therefore true sea temperature boundary-forced signal likely composed having greater than its component, though latter important how affects climate.