CAM5 Scientific Guide

• 1. Acknowledgments
• 2. Introduction
  • 2.1. Brief History
    • 2.1.1. CCM0 and CCM1
    • 2.1.2. CCM2
    • 2.1.3. CCM3
    • 2.1.4. CAM3
    • 2.1.5. CAM4
    • 2.1.6. Overview of CAM5.0
      • 2.1.6.1. The Community Atmosphere Model
      • 2.1.6.2. The CAM Chemistry Model (CAM-CHEM)
      • 2.1.6.3. The Whole Atmosphere Community Climate Model (WACCM)
• 3. Coupling of Dynamical Core and Parameterization Suite
• 4. Dynamics
  • 4.1. Finite Volume Dynamical Core
    • 4.1.1. Overview
    • 4.1.2. The governing equations for the hydrostatic atmosphere
    • 4.1.3. Horizontal discretization of the transport process on the sphere
    • 4.1.4. A vertically Lagrangian and horizontally Eulerian control-volume discretization of the hydrodynamics
    • 4.1.5. Optional diffusion operators in CAM5
    • 4.1.6. A mass, momentum, and total energy conserving mapping algorithm
    • 4.1.7. A geopotential conserving mapping algorithm
    • 4.1.8. Adjustment of pressure to include change in mass of water vapor
    • 4.1.9. Negative Tracer Fixer
    • 4.1.10. Global Energy Fixer
    • 4.1.11. Further discussion
    • 4.1.12. Specified Dynamics Option
    • 4.1.13. Further discussion
  • 4.2. Spectral Element Dynamical Core
    • 4.2.1. Continuum Formulation of the Equations
    • 4.2.2. Conserved Quantities
    • 4.2.3. Horizontal Discretization: Functional Spaces
    • 4.2.4. Horizontal Discretization: Differential Operators
    • 4.2.5. Horizontal Discretization: Discrete Inner-Product
    • 4.2.6. Horizontal Discretization: The Projection Operators
    • 4.2.7. Horizontal Discretization: Galerkin Formulation
    • 4.2.8. Vertical Discretization
    • 4.2.9. Discrete formulation: Dynamics
    • 4.2.10. Consistency
    • 4.2.11. Time Stepping
    • 4.2.12. Dissipation
    • 4.2.13. Discrete formulation: Tracer Advection
    • 4.2.14. Conservation and Compatibility
  • 4.3. Eulerian Dynamical Core
    • 4.3.1. Generalized terrain-following vertical coordinates
    • 4.3.2. Conversion to final form
    • 4.3.3. Continuous equations using
    • 4.3.4. Semi-implicit formulation
    • 4.3.5. Energy conservation
    • 4.3.6. Horizontal diffusion
    • 4.3.7. Finite difference equations
    • 4.3.8. Time filter
    • 4.3.9. Spectral transform
    • 4.3.10. Spectral algorithm overview
    • 4.3.11. Combination of terms
    • 4.3.12. Transformation to spectral space
    • 4.3.13. Solution of semi-implicit equations
    • 4.3.14. Horizontal diffusion
    • 4.3.15. Initial divergence damping
    • 4.3.16. Transformation from spectral to physical space
    • 4.3.17. Horizontal diffusion correction
    • 4.3.18. Semi-Lagrangian Tracer Transport
    • 4.3.19. Mass fixers
    • 4.3.20. Energy Fixer
    • 4.3.21. Statistics Calculations
    • 4.3.22. Reduced grid
  • 4.4. Semi-Lagrangian Dynamical Core
    • 4.4.1. Introduction
    • 4.4.2. Vertical coordinate and hydrostatic equation
    • 4.4.3. Semi-implicit reference state
    • 4.4.4. Perturbation surface pressure prognostic variable
    • 4.4.5. Extrapolated variables
    • 4.4.6. Interpolants
    • 4.4.7. Continuity Equation
    • 4.4.8. Thermodynamic Equation
    • 4.4.9. Momentum equations
    • 4.4.10. Development of semi-implicit system equations
    • 4.4.11. Trajectory Calculation
    • 4.4.12. Mass and energy fixers and statistics calculations
• 5. Model Physics
  • 5.1. Conversion to and from dry and wet mixing ratios for trace constituents in the model
  • 5.2. Deep Convection
    • 5.2.1. Updraft Ensemble
    • 5.2.2. Downdraft Ensemble
    • 5.2.3. Closure
    • 5.2.4. Numerical Approximations
    • 5.2.5. Deep Convective Momentum Transports
    • 5.2.6. Deep Convective Tracer Transport
  • 5.3. Evaporation of convective precipitation
  • 5.4. Prognostic Condensate and Precipitation Parameterization
    • 5.4.1. Introductory comments
  • 5.5. Cloud Microphysics
    • 5.5.1. Overview of the microphysics scheme
      • 5.5.1.1. Sub-grid cloud variability
      • 5.5.1.2. Diagnostic treatment of precipitation
      • 5.5.1.3. Cloud and precipitation particle terminal fallspeeds
      • 5.5.1.4. Ice Cloud Fraction
    • 5.5.2. Radiative Treatment of Ice
    • 5.5.3. Formulations for the microphysical processes
      • 5.5.3.1. Activation of cloud droplets
      • 5.5.3.2. Primary ice nucleation
      • 5.5.3.3. Deposition/sublimation of ice
      • 5.5.3.4. Conversion of cloud water to rain
      • 5.5.3.5. Conversion of cloud ice to snow
      • 5.5.3.6. Other collection processes
      • 5.5.3.7. Freezing of cloud droplets and rain and ice multiplication
      • 5.5.3.8. Melting of cloud ice and snow
      • 5.5.3.9. Evaporation/sublimation of precipitation
      • 5.5.3.10. Sedimentation of cloud water and ice
      • 5.5.3.11. Convective detrainment of cloud water and ice
      • 5.5.3.12. Numerical considerations
  • 5.6. Parameterization of Cloud Fraction
  • 5.7. Aerosols
    • 5.7.1. Emissions
    • 5.7.2. Chemistry
    • 5.7.3. Secondary Organic Aerosol
    • 5.7.4. Nucleation
    • 5.7.5. Condensation
    • 5.7.6. Coagulation
    • 5.7.7. Water Uptake
    • 5.7.8. Subgrid Vertical Transport and Activation/Resuspension
    • 5.7.9. Wet Deposition
    • 5.7.10. Dry Deposition
  • 5.8. Condensed Phase Optics
    • 5.8.1. Tropospheric Aerosol Optics
    • 5.8.2. Stratospheric Volcanic Aerosol Optics
    • 5.8.3. Liquid Cloud Optics
    • 5.8.4. Ice Cloud Optics
      • 5.8.4.1. Tests of MADA
      • 5.8.4.2. Application to
    • 5.8.5. Snow Cloud Optics
  • 5.9. Radiative Transfer
    • 5.9.1. Combination of Aerosol Radiative Properties
    • 5.9.2. Combination of Cloud Optics
    • 5.9.3. Radiative Fluxes and Heating Rates
      • 5.9.3.1. Shortwave Radiative Transfer
      • 5.9.3.2. Longwave Radiative Transfer
    • 5.9.4. Surface Radiative Properties
    • 5.9.5. Time Sampling
    • 5.9.6. Diurnal Cycle and Earth Orbit
    • 5.9.7. Solar Spectral Irradiance
  • 5.10. Surface Exchange Formulations
    • 5.10.1. Land
      • 5.10.1.1. Roughness lengths and zero-plane displacement
      • 5.10.1.2. Monin-Obukhov similarity theory
    • 5.10.2. Ocean
    • 5.10.3. Sea Ice
  • 5.11. Dry Adiabatic Adjustment
  • 5.12. Prognostic Greenhouse Gases
• 6. Extensions to CAM
  • 6.1. Introduction
  • 6.2. Chemistry
    • 6.2.1. Chemistry Schemes
      • 6.2.1.1. The Bulk Aerosol Model
      • 6.2.1.2. CAM-Chem using the Modal Aerosol Model
      • 6.2.1.3. Trop MOZART Chemistry
      • 6.2.1.4. Trop-Strat MOZART Chemistry
      • 6.2.1.5. SOA calculation in CAM-Chem
    • 6.2.2. Emissions
      • 6.2.2.1. Emissions of Trace Gases
      • 6.2.2.2. Biogenic emissions
    • 6.2.3. Boundary conditions
      • 6.2.3.1. Lower boundary conditions
      • 6.2.3.2. Specified stratospheric distributions
      • 6.2.3.3. Upper boundary condition
    • 6.2.4. Lightning
    • 6.2.5. Dry deposition
    • 6.2.6. Wet removal
  • 6.3. Photolytic Approach (Neutral Species)
  • 6.4. Numerical Solution Approach
  • 6.5. Superfast Chemistry
    • 6.5.1. Chemical mechanism
    • 6.5.2. Emissions for CAM4 superfast chemistry
    • 6.5.3. LINOZ
    • 6.5.4. Parameterized PSC ozone loss
  • 6.6. Physical Parameterizations
    • 6.6.1. Domain and Resolution
    • 6.6.2. Molecular Diffusion and Constituent Separation
      • 6.6.2.1. Molecular viscosity and diffusivity
      • 6.6.2.2. Diffusive separation velocities
      • 6.6.2.3. Discretization of the vertical diffusion equations
      • 6.6.2.4. Solution of the vertical diffusion equations
    • 6.6.3. Gravity Wave Drag
      • 6.6.3.1. Adiabatic inviscid formulation
      • 6.6.3.2. Saturation condition
      • 6.6.3.3. Diffusive damping
      • 6.6.3.4. Transport due to dissipating waves
      • 6.6.3.5. Heating due to wave dissipation
      • 6.6.3.6. Orographic source function
      • 6.6.3.7. Non-orographic source functions
      • 6.6.3.8. Numerical approximations
    • 6.6.4. Turbulent Mountain Stress
    • 6.6.5. QBO Forcing
    • 6.6.6. Radiation
      • 6.6.6.1. Longwave radiation
      • 6.6.6.2. Shortwave radiation
      • 6.6.6.3. Volcanic Heating
    • 6.6.7.  chemistry
      • 6.6.7.1. Chemical Mechanism (Neutral Species)
      • 6.6.7.2. Stratospheric Aerosols
      • 6.6.7.3. Sedimentation of Stratospheric Aerosols
      • 6.6.7.4. Ion Chemistry
    • 6.6.8. Electric Field
      • 6.6.8.1. Low- and midlatitude electric potential model
      • 6.6.8.2. High–latitude electric potential model
      • 6.6.8.3. Combing low–/ mid–latitude with the high latitude electric potential
      • 6.6.8.4. Calculation of electric field
      • 6.6.8.5. Calculation of electrodynamic drift velocity
      • 6.6.8.6. Ion drag calculation
    • 6.6.9. Boundary Conditions
• 7. Slab Ocean Model
  • 7.1. Open Ocean Component
  • 7.2. Thermodynamic Sea Ice Model
  • 7.3. Evaluation of the Ocean Flux
• 8. Sea Ice Thermodynamics
  • 8.1. Basic assumptions
  • 8.2. Fundamental Equations
  • 8.3. Snow and Ice Albedo
  • 8.4. Ice to Atmosphere Flux Exchange
  • 8.5. Ice to Ocean Flux Exchange
  • 8.6. Brine Pockets and Internal Energy of Sea Ice
  • 8.7. Open-Water Growth and Ice Concentration Evolution
  • 8.8. Snow-Ice Conversion
  • 8.9. Numerics
    • 8.9.1. Case I: Snow accumulated with no melting
    • 8.9.2. Case II: Snow free with no melting
    • 8.9.3. Case III: Snow accumulated with melting
    • 8.9.4. Case IV: No snow with melting
    • 8.9.5. Temperature Adjustment Due to Melt/Growth
• 9. Initial and Boundary Data
  • 9.1. Initial Data
  • 9.2. Boundary Data