Large Scale Group

The objective of the Large Scale Group is to maintain and improve the global medium-range forecast system from which depend the regional and local components of the Canadian forecast system. This system is based on an unified approach which can handle all aspects of environmental modeling. This strategy has lead to the development and implementation of a single dynamic core, the Global Environmental Multiscale (GEM) model. The objective of the Large Scale Group materializes in research and development in three converging directions:

• Increase significantly the horizontal resolution of the global component of the GEM model. This is done while proceeding to a complete revision of the physics parameterization package.
  
  
• Extend the computational domain in the vertical into the lower mesosphere. This action, while resulting in a better simulation in the stratosphere, allows for the assimilation of many supplementary satellite radiance channels in this region and improves the quality of the medium to long range forecasts in the troposhere.
  
  Develop and adapt to the global environment an analysis of the surface terrain parameters based on an advanced surface processes scheme (Interactions-Surface-Biosphère-Atmosphère (ISBA)).
  
  
  

These actions are now progressing in the framework of a three-dimensional variational analysis system. Adjustments will be made to take into account the new problems or constraints of the quadri-dimensional analysis system now being developped.