Wolter, K., and M.S. Timlin, 1998: Measuring the strength of ENSO -
how does 1997/98 rank? Weather, 53, 315-324
Rasmusson, E.G., and T.H. Carpenter, 1982: Variations in tropical sea
surface temperature and surface wind fields associated with the
Southern Oscillation/El NiC1o. Mon. Wea. Rev., 110, 354-384.
Wolter, K., 1987: The Southern Oscillation in surface circulation and
climate over the tropical Atlantic, Eastern Pacific, and Indian Oceans
as captured by cluster analysis. J. Climate Appl. Meteor., 26,
540-558.
Wolter, K., and M.S. Timlin, 1993: Monitoring ENSO in COADS with a
seasonally adjusted principal component index. Proc. of the 17th
Climate Diagnostics Workshop, Norman, OK, NOAA/N MC/CAC, NSSL,
Oklahoma Clim. Survey, CIMMS and the School of Meteor., Univ. of
Oklahoma, 52-57.