New Zealand's Environment Reporting Series: The Ministry for the Environment and Statistics New Zealand
The Interdecadal Pacific Oscillation (IPO) is a long-term oscillation of sea-surface temperatures in the Pacific Ocean that can last from 20 to 30 years. Its positive and negative phases affect the strength and frequency of El Niño and La Niña. In New Zealand, the positive phase is linked to stronger west to southwest winds and more rain in the west. This trend is reversed during the negative phase. More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.