What is responsible for the strong observed asymmetry in teleconnections between El Nino and La Nina?

  • 1 March 2014
  • Number of views: 3387
What is responsible for the strong observed asymmetry in teleconnections between El Nino and La Nina?

Research funded by CPO’s Modeling, Analysis, Prediction, and Projections (MAPP) program focusing on observed asymmetry in teleconnections between El Nino and La Nina was published in the February issue of Geophysical Research Letters.

According to the research, a large asymmetric component (El Niño + La Niña) of El Niño–Southern Oscillation (ENSO)-related teleconnections over North America is found during 1984–2009 that is comparable in strength to the commonly studied symmetric component (El Niño − La Niña).

The scientists diagnosed climate reforecasts spanning this period in order to understand the processes responsible for the observed asymmetry.

They confirmed that an asymmetric component is indeed a fundamental property of atmospheric responses to recent ENSO forcing. Each and every composite of a 16-member reforecast ensemble has appreciable asymmetry in tropical Pacific rainfall, upper tropospheric Pacific-North American circulation patterns, and contiguous U.S. surface temperatures.

There is considerable sampling variability in the magnitude of this asymmetric component among individual reforecast composites.

Therefore, the scientists argued that the true sea surface temperature boundary-forced signal of ENSO teleconnections is likely composed of a symmetric component having greater magnitude than its asymmetric component, though the latter is an important property of how ENSO affects North American climate.  

To view the full report, visit: http://onlinelibrary.wiley.com/doi/10.1002/2013GL058964/pdf



Dr. Annarita Mariotti
MAPP Program Director
P: 301-734-1237
E: annarita.mariotti@noaa.gov

Dr. Daniel Barrie
MAPP Program Manager
P: 301-734-1256
E: daniel.barrie@noaa.gov

Alison Stevens*
MAPP Program Specialist
P: 301-734-1218
E: alison.stevens@noaa.gov

Emily Read*
MAPP Program Assistant
P: 301-734-1257
E: emily.read@noaa.gov

  • Subscribe to our newsletter!

«May 2018»


Americans’ health, security and economic wellbeing are tied to climate and weather. Every day, we see communities grappling with environmental challenges due to unusual or extreme events related to climate and weather. In 2017, the United States experienced a record-tying 16 climate- and weather-related disasters where overall costs reached or exceeded $1 billion. Combined, these events claimed 362 lives, and had significant economic effects on the areas impacted, costing more than $306 billion. Businesses, policy leaders, resource managers and citizens are increasingly asking for information to help them address such challenges.


Climate Program Office
1315 East-West Hwy, Suite 1100
Silver Spring, MD 20910