Atmospheric Model Component

Unified Model (UM)

What is the Met Office UM?

The Unified Model (UM) is a numerical model of the atmosphere used for both weather and climate applications, developed by the Met Office in the United Kingdom (UK). It includes solutions of the equations of atmospheric fluid dynamics with advanced parameterizations of subgrid-scale physical processes like convection, cloud formation and atmospheric radiation.

The Unified Model gets its name because a single model is used across a wide range of both timescales (nowcasting to centennial) and spatial scales (sub km convective scale to global climate modelling).

The UM is used by several international operational meteorology and research organizations and these contribute towards its development through the UM partnership.

How is the UM used?

The UM Model component represents the atmosphere in many of the ACCESS Models used at regional and global scales.

The ACCESS-CM2 climate model and ACCESS-ESM1-5 earth system model use versions of the UM as their atmospheric components.

The Australian Bureau of Meteorology operational 12 km spatial resolution global forecasting system uses the Unified Model, as part of ACCESS for:

  • Forecasting of extreme events and emergencies such as heatwaves, bushfires, cyclones, floods, coral bleaching, sea-level rise, coastal inundation and more.
  • Daily and seasonal weather forecasts

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