Toward a classification of the Central Pacific El Niño

Abstract

We investigate the various methods currently available for distinguishing between the Central Pacific (CP) El Ni�o (or "El Ni�o Modoki") and the canonical El Ni�o by considering 10 different methods and 5 sea surface temperature (SST) datasets from 1880 to 2010. Years which are classified as CP El Ni�os with the greatest convergence between method and SST dataset are considered to provide a more robust identification of these events. The results identify 13 yr which are classified the most consistently as CP events: 1885/1886, 1914/1915, 1940/1941, 1958/1959, 1963/1964, 1968/1969, 1977/1978, 1986/1987, 1991/1992, 2002/2003, 2003/2004, 2004/2005 and 2009/2010. Our findings also indicate the persistence of CP events throughout the time period investigated, inciting the role of multidecadal natural climate variability in generating CP El Ni�os