During the 10-year long record of the coastal station, a significant temperature increase could be seen (Fig. 5). Where trends are involved, we can ask whether they belong to decadal or longer periods. The 1979–1989 time series occurred during the same positive Pacific Decadal Oscillation (PDO, Mantua et al., 1997), which lasted from May 1976 to July 1998, with a temporary inversion from September 1988 to July 1991.