CCSM Atmospheric Model Working Group Summary

1
CCSM Atmospheric Model Working Group Summary

• J. J. Hack, D. A Randall
• AMWG Co-Chairs
• CCSM Workshop, 28 June 2001

2
Strengths of New Model

• Improvements in several important simulation
  features
• precipitable water
• precipitation distribution
• polar surface radiation fluxes
• eastern ocean solar energy budget
• eastern Pacific surface wind stress
• Scientifically defensible extendible framework
• spectral Eulerian dynamics with reduced linear
  grid
• 26 levels
• prognostic cloud water
• generalized cloud overlap (plus requisite changes
  to LW SW)
• updated long wave water vapor absorption
  formulation
• modified deep convection parameterization

3
June 2001 Workshop Participation

• 12 oral and 8 poster presentations on variety of
  topics
• radiation transfer schemes
• planetary boundary layer
• cloud parameterization techniques
• high resolution extended domain simulations
• numerical methods
• diagnostic approaches and analyses
• Open discussion
• science and development priorities
• issue-oriented focus groups
• e.g., double ITCZ, clouds, ...

4
AMWG Development Process

• Extend Standard Experimental Procedures
• uncoupled/coupled experimental frameworks
• incorporation of tracers
• Extend Standard Diagnostic Procedures
• more comprehensive evaluation of proposed changes
  
• include variability measures
• model against observations model against model
• make all development activities results web
  accessible
• entrain broader community as participants in
  model analysis

5
Immediate Future for the AMWG

• Maintain general AMWG research infrastructure
• needs to support research activities on multiple
  fronts
• boundary layer
• dynamical cores
• stratiform clouds
• middle atmosphere (e.g., WACCM)
• radiation parameterization alternatives
• cumulus parameterization alternatives
• AMWG diagnostic infrastructure
• needs to continue to grow in scope and complexity
• evaluate model behavior across wide range of time
  scales
• include dominant modes of climate variability in
  standard analysis
• continued involvement of other CCSM working groups

6
Other matters for exploration

• Prioritize incorporation of new/improved physics
• seek input from development, diagnostic, and
  application communities
• Organize/prioritize activities around simulation
  deficiencies
• solution for double ITCZ problem
• solutions to weak internal variability
• representation of clouds
• Explore ways to establish stronger links to
  observational community
• e.g., satellite remote sensing community