Parameter Tree:
EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > SEA SURFACE TEMPERATURE INDICES > TRANS-NINO INDEX

Definition:
The timeseries is calculated from the HadISST and the NCEP OI Datasets. It is the standardized Nina 12 minus the Nina 4 with a 5 month running mean applied which is then standardized using the 1950-1979 period.

Reference:
Earth Systems Research Laboratory, Physical Sciences Division, NOAA,
http://www.esrl.noaa.gov/psd/gcos_wgsp/Timeseries/TNI/

Kevin E. Trenberth and David P. Stepaniak: J. Climate, 14, 1697-1701.