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Atmosphere-Ocean Global Circulation Model (AOGCM)

Atmosphere-Ocean Global Circulation Models (AOGCM), also known as 'coupled atmosphere-ocean models', are global climate models that model both atmospheric and ocean processes and interactions between them. 

In detail

The ocean has a large influence on atmospheric processes, therefore it is important to have a fully coupled ocean-atmospheric model in order to model the transient (continuous) changes in climate through the century.

Typically, the term Global Climate Model (GCM) is used to refer to climate models that reflect both atmosphere and ocean processes and feedbacks. For UKCP09, the Met Office Hadley Centre HadCM3 coupled global climate model is used. 

Fully coupled GCMs are typically on a resolution of 2-3° (~200-300 km) because they are computationally intensive. In UKCP09, HadCM3 was the fully coupled model used to generate the transient projections. 

Find out more


  • Further explanation is provided in  of the UKCP09 Climate Change Projections report.
  • An overview of how probabilistic projections are created and presented in UKCP09 is described in  of the UKCP09 Briefing report.
  • More details are provided in  of the UKCP09 Climate Change Projections report, including an overview of the methodology in .
  • IPCC Fifth Assessment Report, Working Group 1 report  The Physical Science Basis , Chapter 8