Figure 3.3: Differences between the long-term average rainfall and that in ENSO years (the rainfall anomaly), in percent, for summer (December, January, February)
The ENSO rainfall is the average of the 10 strongest ENSO events between 1960–2007. (The insert box shows the ENSO years, where 1964 is December 1963 to February 1964, etc.)
Return to the point in the document where this figure is located.
Text description of figure
The figure shows two maps of New Zealand, illustrating the differences between the long-term average rainfall and that in ENSO years (the rainfall anomaly), in percent, for summer (December, January, February). The ENSO rainfall is the average of the 10 strongest ENSO events between 1960–2007. The first map shows rainfall anomalies averaged over the 10 strongest El Nino years (these were in 1964, 1966, 1969, 1973, 1983, 1987, 1992, 1995, 1998, and 2003). The rainfall is more than 15 percent lower in many parts of the east coast of both islands and between 10 and 15 percent lower in much of the rest of the South Island in the Bay of Plenty. In parts of Buller and the west coast of the North Island rainfall is up to 5 percent higher.
Similarly, the second map shows rainfall anomalies averaged over the 10 strongest La Nina years (1965, 1968, 1971, 1974, 1976, 1985, 1989, 1996, 1999 and 2000) shown in, the picture is quite different. Through much of the North Island rainfall is up to 15 percent higher, as well as the very north of the South Island and parts of Northern Otago. Most of the rest of the South Island together with the Wellington/Kapiti region receives up to 15 percent lower rainfall.
