Climate index (Q404)
Subject, term, tag: Climate index
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | Climate index |
Subject, term, tag: Climate index |
Statements
IPCC Glossary v1.5
1 reference
27 May 2026
A time series constructed from climate variables that provides an aggregate summary of the state of the climate system. For example, the difference between sea level pressure in Iceland and the Azores provides a simple yet useful historical North Atlantic Oscillation (NAO) index. Because of their optimal properties, climate indices are often defined using principal components — linear combinations of climate variables at different locations that have maximum variance subject to certain normalization constraints (e.g., the Northern Annular Mode (NAM) and Southern Annular Mode (SAM) indices which are principal components of Northern Hemisphere and Southern Hemisphere gridded pressure anomalies, respectively). Definitions of observational indices for Modes of climate variability can be found in Annex VI of the AR6 WGI report. (English)
IPCC Glossary v1.5
1 reference
27 May 2026