Joint UK Land Environment Simulator (JULES)

The Joint UK Land Environment System is a land surface model that has evolved from the Met Office Surface Exchange Scheme (MOSES).  JULES has been packaged into a community land surface model that can be used offline, but is also the new land surface model of the Unified Model. This  provides a tool for the UK research community to study land surface processes in a flexible way and to contribute to the development of a state-of-the-art model.  Because JULES can be easily operated within the Unified Model, the impact of land surface on weather prediction and climate can be readily assessed.
Improvements to JULES will allow improvements to projections of climate change, from the global scale (for example due to improved representation of vegetation and carbon cycle feedbacks) to the local scale (for example through improved representation of the effects of urban areas on their own local climate).  This is important for providing more robust assessments of the magnitude of climate change and its impacts,  and to inform decision-making on emissions reductions and adaptation.
Another key aspect of JULES is that it can be used "offline" outside of the Unified Model as a physical impacts model.  Its unique contribution here is that it includes many processes relevant to impacts assessments in a fully-integrated manner - for example, the impacts of climate change and carbon dioxide fertilization on ecosystems can have important knock-on effects on hydrology, with consequent implications for water resources.  These interactions are usually not included in impacts assessments focusing on one particular process - JULES will therefore allow a more complete view.

Key aims

  • Increase our understanding of the interactions between the land and the atmosphere
  • Investigate the impact of the land surface on the predictability of weather and climate on all timescales 
  • Develop our understanding of the land processes that contribute towards the changing climate, for example through changes in surface hydrology and the terrestrial carbon cycle
  • Investigate the interactions between different impacts of climate change on the land surface

Applications of JULES

External collaboration page

Joint UK Land Environment Simulator