Nino 3 Index Reconstruction: readme file
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              World Data Center for Paleoclimatology, Boulder
                                and 
                   NOAA Paleoclimatology Program
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NOTE: PLEASE CITE ORIGINAL REFERENCES WHEN USING THIS DATA!!!!!

CONTRIBUTORS: Cook, E.R.
NAME OF DATA SET: Nino 3 Index Reconstruction

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2000-052.

SUGGESTED DATA CITATION: Cook, E.R., 2000, 
Nino 3 Index Reconstruction.  International Tree-Ring Data Bank.  
IGBP PAGES/World Data Center-A for Paleoclimatology 
Data Contribution Series #2000-052.  
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

ORIGINAL REFERENCE: Unpublished data.

LAST UPDATE:  8/2000 (Original receipt by WDC-A Paleo)
GEOGRAPHIC REGION: Pacific Ocean 
PERIOD OF RECORD: 1408-1978 AD

LIST OF FILES: Nino3.readme.txt (this file), nino3.recon.txt.

DESCRIPTION:
Reconstruction of the Nino3 Index of El Nino-Southern Oscillation 
variability, for the months of December through February each year, 
based on tree ring data from northern Mexico and Texas, USA.

The reconstruction uses factor scores from a Principal Components Analysis (PCA) 
of time t and selected t-1 and t+1 lags of 14 tree-ring chronologies from northern
Mexico (Durango and Chihuahua) and the southwestern U.S.A. (Arizona, Utah and
New Mexico) plus the first two factor scores from a network of 9 chronologies 
in OK and TX as independent variables.  All chronologies were compiled from 
indices of tree growth (earlywood or total ring width) detrended to remove 
biological trends (Cook 1985).