Southern Annular Mode monthly values, January 1979–December 2016

A consistent band of westerly wind flows across the Southern Hemisphere and circles the South Pole. The Southern Annular Mode (SAM) describes how this band moves, either north towards the equator (negative phase) or south towards Antarctica (positive phase). A negative phase typically causes increased westerlies, unsettled weather, and storms in New Zealand. A phase can last several weeks, but changes can be rapid and unpredictable. The SAM is one of three climate oscillations that affect our weather. The resulting changes in air pressure, sea temperature, and wind direction can last for weeks to decades, depending on the oscillation. 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.

Data and Resources

Additional Info

Field Value
Author Ministry for the Environment
Maintainer Ministry for the Environment
Maintainer Email Ministry for the Environment
Created 2017-10-12T21:10:18.131877Z
Date modified 2017-10-18T20:35:01.160057Z
Efficiency Type
Dollars Saved
Jurisdiction New Zealand
Language English
Source Identifier
Record created May 3, 2018, Last Updated May 3, 2018