1 / 43

Unveiling the NCAR Community Climate System Model (CCSM)

Discover the elite CCSM, delving into Earth's climate complexity. Investigate seasonal variability, explore historical climate data, and anticipate future trends. Learn about the latest version and contributions to IPCC reports. Gain insights into model components and computational requirements. Join the quest to understand Earth's climate with CCSM.

lafortune
Download Presentation

Unveiling the NCAR Community Climate System Model (CCSM)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. An Introduction to NCAR Community Climate System Model (CCSM) Wanli Wu (wanliwu@ucar.edu) National Center for Atmospheric Research (NCAR)

  2. What is CCSM • Community Climate System Model, one of elite climate models in the world to picture the complexity of the Earth’s climate. • It has been developed by NCAR scientists in collaboration with researchers at Universities, National Laboratories. • The CCSM program is sponsored by US NSF and Dept. of Energy. • It houses at National Center for Atmospheric Research with open source codes, documents for all interested users in the world.

  3. Develop a comprehensive model to study the Earth’s Climate. Investigate seasonal and interannual variability of the climate. Explore the history of the Earth’s climate. Estimate the future of the climate. Release of a new version (CCSM3, June, 2004). Studies linking SST fluctuations, extreme events and extratropic variability. Simulations of paleoclimate. Contributions to IPCC AR4. Special issues: J. Climate (June 1, 2006) and IJHPCA (2005) CCSM Program:Scientific Objectives & Recent Accomplishments

  4. The GCM Family Tree

  5. Evolution of Community Climate System Model (CCSM)

  6. Complexity of Models: Broader and Deeper

  7. Models of Everything

  8. Modules of Models

  9. CCSM: components • atm: Atmospheric model (CAM3, T85L26) • lnd: Land model (CLM3, T85) • ocn: Oceanic Model (POP 1.4, x1L40) • ice: Sea ice model (CSIM5, x1) • cpl: Coupler (CPL 6)

  10. CCSM3: Computational Requirements • IBM power 3-5 • SGI Altix & Origin • Cray X1/X1E & XT3 • NEC SX • Xeon & Itanium Linux On IBM power 4: T85x1 1146 CPU hrs/myr T42x1 293 CPU hrs/myr T31x3 62 CPU hrs/myr

  11. The Atmospheric model: CAM • Dynamics: • Spectral • Finite volume • Physics: • Deep & shallow convection • Prognostics condensate & precipitation parameterization • Diagnostic parameterization of cloud fraction • Band-model radiative transfer • Prognostic and diagnostic aerosols

  12. Horizontal grids of the Atmospheric Model

  13. The Land model: CLM

  14. CLM sub-grid Hierarchy

  15. The Ocean model: POP • A Bryan-Cox type and z-coordinate model. • Controlled by primitive equations subject to hydrostatic & Boussinesq approximations. • Conserved global ocean volume • Gent-McWilliam isopycnal mixing • KPP vertical mixing • x1L40 or x3L25 • 1/10 degree

  16. POP Grids

  17. Sea ice model: CSIM • Ice dynamics • Ice thermodynamics • Subgrid scale ice thickness distribution (ITD)

  18. Coupling methodology • The physical component models communicate through the coupler in a completely asynchronous manner (different grid and different time steps). • The coupler • governs the execution and time evolution of the entire system. • provides interface flux conditions and state information to each model. • enforces flux conservation.

  19. Model climatology: zonal mean air temperature

  20. Model climatology: improved from CCSM2

  21. Model climatology: sea surface temperature

  22. Model climatology: improved SST

  23. Model climatology: Continental temperature biases

  24. Model climatology: precipitation

  25. Model climatology: improved precipitation

  26. Model climatology: seasonal cycle of sea ice

  27. CFC-11 Inventory

  28. Regional features: N. Atlantic CFC-11

  29. Regional features:Tibet Plateau surface climate

  30. Regional features: south Asia monsoon

  31. Tropical variability: ENSO variance

  32. Tropical variability: ENSO power spectra

  33. Tropical variability: Symmetric equatorial waves

  34. Tropical variability:Asymmetric equatorial waves

  35. Pressing Issues, Challenges & Opportunity • Representation of major variability modes • Pacific double ITCZ • Continental precipitation and temperature biases • Eastern Ocean boundary SST biases • Eastern Pacific semiannual SST cycle • Arctic downward short-wave radiation bias

  36. Work in progress: Chemistry • Atmospheric chemistry • Terrestrial C/N cycle, ecosystems • Marine biogeochemical cycle

  37. Work in progress: Nesting • WRF --> CAM • ROMS --> POP

  38. Work in progress: weather-climate interaction • Crossing-scale interaction • Test climate models as weather models

  39. Work in progress: tropical variability • Reduce tropical biases related to MJO, ENSO

  40. Work in progress: Air quality/pollution vs. climate • Climate model application

  41. CCSM4: Community Earth System Model (CESM, 2009?) • A model of everything • More component model options

  42. Community Earth System Model

  43. THANK YOU

More Related