Toward a classification of the Central Pacific El Ni o

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.