Southern Annular Mode (Q1043)
Subject, term, tag: Southern Annular Mode
- Southern Annular Mode (SAM)
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Southern Annular Mode |
Subject, term, tag: Southern Annular Mode |
|
Statements
IPCC Glossary v1.5
1 reference
27 May 2026
The leading mode of climate variability of Southern Hemisphere sea-level pressure and geopotential height, which is associated with the strength and latitudinal shifts in the mid- to high-latitudes westerly wind belt. The SAM is also known as the Antarctic Oscillation (AAO). A positive SAM phase is defined as lower-than-normal pressures over the polar regions and higher-than-normal pressures in the southern mid-latitudes, with a contraction towards Antarctica and strengthening of the westerly wind belt. The negative SAM phase exhibits positive high latitude pressure anomalies, negative mid-latitude pressure anomalies and a weaker westerly flow expanded towards the equator. See Section AIV.2.2 in Annex IV of the AR6 WGI report. (English)
IPCC Glossary v1.5
1 reference
27 May 2026