Southern Oscillation Index Reconstruction: SOI.readme file
-----------------------------------------------------------------------
               World Data Center A- Paleoclimatology
-----------------------------------------------------------------------
NOTE: PLEASE CITE ORIGINAL REFERENCES WHEN USING THIS DATA!!!!!

CONTRIBUTORS:
D.W. Stahle (1), R.D. D'Arrigo (2), P.J. Krusic (2), M.K. Cleaveland (1),
E.R. Cook (2), R.J. Allan (3), J.E. Cole (4), R.B. Dunbar (5), M.D. Therrell
(1), D.A. Gay (1), M.D. Moore (6), M.A. Stokes (7), B.T. Burns (8), J.
Villanueva-Diaz (9) and L.G. Thompson (10)
  (1) Dept. of Geosciences Tree-Ring Lab., U. of Arkansas, Fayetteville,
      AR 72701;  (501) 575-3159, dstahle@comp.uark.edu
  (2) Tree-Ring Lab., Lamont-Doherty Earth Observatory, Palisades, NY
  (3) Climate Impact Group, CSIRO Mordialloc, Victoria, Australia
  (4) Geological Sciences/INSTAAR, U. of Colorado, Boulder, CO
  (5) Dept. of Geology and Environmental Science, Stanford U., Stanford, CA
  (6) Scripps Inst. of Oceanography, La Jolla, CA
  (7) Lab. of Tree-Ring Res., The U. of Arizona, Tucson, AZ
  (8) Native Seed SEARCH, Tucson, AZ
  (9) INIFAP, San Luis Potosi, Mexico
(10) Byrd Polar Research Center, Ohio State U., Columbus, OH

NAME OF DATA SET:  Southern Oscillation Index Reconstruction

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 1998-038
SUGGESTED DATA CITATION: Stahle, et al, 1998, Southern Oscillation 
Index Reconstruction.  International Tree-Ring Data Bank.  
IGBP PAGES/World Data Center-A for Paleoclimatology Data Contribution 
Series #1998-038.  NOAA/NGDC Paleoclimatology Program,
Boulder CO, USA

ORIGINAL REFERENCES:
Allan, R.J., J. Lindesay and D. Parker.  1996.  El Nino/Southern
Oscillation & Climatic Variability.  CSIRO Publishing.  408 pp.

Cook, E.R.  1985.  A Time Series Approach to Tree Ring Standardization.
PhD dissertation.  Tucson, AZ: U. of Arizona.  171 p. University Microfilms
International, 300 N. Zeeb Rd, Ann Arbor, MI 48106

Stahle, D.W., R.D. D'Arrigo, P.J. Krusic, M.K. Cleaveland, E.R. Cook,
R.J. Allan, J.E. Cole, R.B. Dunbar, M.D. Therrell, D.A. Gay, M.D. Moore,
M.A. Stokes, B.T. Burns, J. Villanueva-Diaz and L.G. Thompson.  1998.
Experimental dendroclimatic reconstruction of the Southern Oscillation.
Bull. American Meteorological Society 79: 2137-2152.

LAST UPDATE:  11/1998 (original receipt at WDC-A Paleo)
GEOGRAPHIC REGION: Southern Pacific 
PERIOD OF RECORD:  1706 A.D. - 1997 A.D.  

LIST OF FILES: SOI.recon.txt-Reconstructed winter (DJF) SOI, 1706-1977. Format I5,F9.3
SOI.obs.txt-Observed winter (DJF) SOI, 1876-1996 (Allan et al. 1996),
adjusted to make the mean 1879-1977 equal 0.0.  Format I4,F6.2

DESCRIPTION:
EXPERIMENTAL DENDROCLIMATIC RECONSTRUCTION OF THE SOUTHERN OSCILLATION
This file documents reconstruction of the winter (DJF) season of Allan's
version of the Southern Oscillation Index (SOI).  It was reconstructed by
using the 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), the southwestern U.S.A. (Arizona, Utah and
New Mexico) and Java, Indonesia 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).  The
dependent variable was winter (DJF) average SOI compiled by R. Allan, based
on normalized Tahiti minus Darwin sea level pressure, multiplied by 10
(Allan et al. 1996), adjusted so the mean of the period 1879-1977
equals 0.0.

The reconstruction is the basis for the paper (D.W. Stahle et al. 1998).