The most accurate way of identifying El Niño or La Niña weather phases is to measure the annual air-pressure variation across the Pacific (between Tahiti in the east and Darwin in the west). These measurements are known as the Southern Oscillation Index. A variation of below -1 indicates an El Niño weather pattern. When the variation is above +1, La Niña is active.
Te whakamahi i tēnei tūemi
This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.