Conclusion

The climate regime that dominated in the equatorial Pacific since the late 1970s appears to have ended in the late 1990s. The shift to a new regime was not as apparent as the previous shift in the late 1970s (which was quite unique), and the current conditions are not necessarily close in every aspect to those during the pre-1977 period. Nevertheless, it is expected that the new regime, which will probably last until about 2014, will be characterized by relatively low background SSTs and more frequent La Niña events. This may also weaken the global warming signal (the global trend analysis is coming soon). The evolution of El Niño events will follow the “canonical” scenario, first developing along the South American coast and then moving westward. The next El Niño (and, possibly a strong one, similar to the 1972/73 event) is expected in 2009, but may come as early as the end of this year.