1. CCSM Meeting June 23-27, 2003 Status of CCSM2.2 Bill Collins Incoming Chair, CCSM Scientific Steering Committee National Center for Atmospheric Research Boulder, Colorado Development and status of CCSM2.2 CCSM Science & Business Plans for 2004-2008 Major simulation issues in CCSM2 Improvements in components to address biases WG plans for future improvements & experiments

2. CCSM Meeting June 23-27, 2003 Ongoing Development of CCSM CCSM 2.0 May 2002 CCSM 2.0.1 Minor changes to code structure CCSM 2.2 Integration of new components October 2002 “Late” Spring 2003 CCSM 2.X Physics adjustments, dycore decision Fall 2003

3. CCSM Meeting June 23-27, 2003 Status of CCSM and its IPCC Applications CCSM2.2 was completed in June 2003: –New versions of model components –New coupler CPL6 Test integrations are underway. Next major issue: decision on atmospheric dynamical core

4. CCSM Meeting June 23-27, 2003 Development Plans for CCSM, 2004-08 http://www.ccsm.ucar.edu/management http://www.ccsm.ucar.edu/management CCSM Science Plan –Brief history of the CCSM program –Scientific accomplishments of CCSM2 –Status of the CCSM –Planned climate experiments –Near-term program for understanding coupled model –Scientific questions needing major new capabilities CCSM Business Plan –Current resources –Vision for the future and resource requirements

5. CCSM Meeting June 23-27, 2003 Main Model Biases in CCSM2 Double ITCZ and extended cold tongue  Cold tongue mitigated in new POP, double ITCZ in CAM 2.X Overestimation of winter land surface temperatures  Bias largely eliminated in CLM 2.2 + CAM 2.X Underestimation of tropical tropopause temperatures  Bias reduced in CAM 2.X Erroneous cloud response to SST changes  Signs and pattern of response corrected in CAM 2.X Errors in E. Pacific surface energy budget  Overestimation of insolation larger in prototype Underestimation of tropical variability  Underestimation still present

6. CCSM Meeting June 23-27, 2003 Double ITCZ

7. CCSM Meeting June 23-27, 2003 Winter Land Surface Temperatures

8. CCSM Meeting June 23-27, 2003 Tropical Tropopause Temperatures

9. CCSM Meeting June 23-27, 2003 Cloud Forcing Response to Tropical SSTs

10. CCSM Meeting June 23-27, 2003 East Pacific Surface Energy Budget

11. CCSM Meeting June 23-27, 2003 Tropical Variability

12. CCSM Meeting June 23-27, 2003 Ocean Model Changes for CCSM 2.2 KPP boundary layer Double Diffusion Solar Absorption (Chlorophyll) Ideal Age and Passive Tracer Infrastructure Ocean Currents in Air-Sea Fluxes

13. CCSM Meeting June 23-27, 2003 CONTROLAll Physics + Numerical MODS Jan July Mixed Layer Depths

14. CCSM Meeting June 23-27, 2003 SST Signature of Solar Absorption

15. CCSM Meeting June 23-27, 2003 SST Signature of All Ocean Modifications

16. CCSM Meeting June 23-27, 2003 New Physics for High Resolution: Anisotropic Mixing

17. CCSM Meeting June 23-27, 2003 New Physics for High Resolution: Reduced Lateral Viscosity

18. CCSM Meeting June 23-27, 2003 Goal For CCSM2: state-of-the-art model with focus on biogeophysics, hydrology, river routing Goal For Next Few Years: Natural and human-mediated changes in land cover and ecosystem functions and their effects on climate, water resources, and biogeochemistry Process: Continue to develop and improve existing physical parameterizations in the model while adding new biological and chemical process Land Model Working Group Hydrology Drainage Canopy Water Evaporation Interception Snow Melt Sublimation Throughfall Stemflow Infiltration Surface Runoff Evaporation Transpiration Precipitation Soil Water Redistribution Direct Solar Radiation Absorbed Solar Radiation Diffuse Solar Radiation Longwave Radiation Reflected Solar Radiation Emitted Long- wave Radiation Sensible Heat Flux Latent Heat Flux uaua 0 Momentum Flux Wind Speed Soil Heat Flux Heat Transfer Photosynthesis Biogeophysics

19. CCSM Meeting June 23-27, 2003 Biogeochemistry Goal: Enable parameterization of terrestrial carbon cycle New hierarchical data structures within a grid cell: grid cell  land unit  snow/soil columns  plant functional types. Does not change climate. Allow multiple plant types on a single soil column. Minor climate changes. Biogeophysics I Goal: Minor changes or bug fixes Allow precipitation to be rain/snow mix Improve 2-m temperature diagnostic Remove discontinuity in bulk density of snow Biogeophysics II Goal: Reduce excessive summertime temperatures in arid regions. Reduce Arctic winter warm temperature bias Turbulent exchange of heat from ground Fractional cover of snow on ground Model Development For CLM2.2

20. CCSM Meeting June 23-27, 2003 Increased Reflection of Insolation by Snow CLM2.2CLM2

21. CCSM Meeting June 23-27, 2003 Increased Turbulent Heat Flux from Vegetated Surfaces CLM2.2CLM2

22. CCSM Meeting June 23-27, 2003 Effects on Land Surface Temperatures 22-year (1979-2000) simulations of CAM2 with CLM2.2 CLM2.2 significantly cools surface air temperature CLM2.2CLM2

23. CCSM Meeting June 23-27, 2003 Long-Term Development Tasks TaskScientific Lead Physics Excessive interception Guiling Wang Efficient leaf temperature algorithm Guiling Wang Canopy storage of heat,moisture, CO 2 Scott Denning, Ian Baker Sunlit/shaded canopy Peter Thornton Snow hydrology Zong-Liang Yang, Guo-Yue Niu Runoff Zong-Liang Yang, Guo-Yue Niu 2-m temperature over grass Robert Dickinson Surface albedos Xubin Zeng, Robert Dickinson Biogeochemistry Terrestrial carbon cycle Peter Thornton Water isotopes Natalie Mahowald, David Noone Mineral aerosols Natalie Mahowald, Sam Levis Land Cover Change Agroecosystems Gordon Bonan, Johan Feddema, Keith Oleson Urban land cover Gordon Bonan, Johan Feddema, Keith Oleson Prognostic biogeography Sam Levis, Gordon Bonan

24. CCSM Meeting June 23-27, 2003 Changes to Physics in CAM Relative to CAM2 Clouds and condensate:Clouds and condensate: –Improved prognostic cloud water & moist processes –Transfer of mixed phase precipitation to land surface –Improved cloud parameterization Radiation:Radiation: –Shortwave forcing by diagnostic aerosols –Updated SW scheme for H2O absorption –Updated LW scheme for LW absorption and emission Surface models:Surface models: –Introduction of CLM 2.2 –Reintroduction of Slab Ocean Model (SOM) Energy fixers for dynamics + diagnosticsEnergy fixers for dynamics + diagnostics

25. CCSM Meeting June 23-27, 2003 Increase in Cloud Amount, CWP CAM 2.X – CAM 2

26. CCSM Meeting June 23-27, 2003 Decrease in Clear-sky Surface Insolation CAM 2.X – CAM 2

27. CCSM Meeting June 23-27, 2003 Cloud Response to Tropical SST Variations CAM 2.X

28. CCSM Meeting June 23-27, 2003 Higher Tropopause Temperatures CAM 2CAM 2.X CAM 2.X – CAM 2

29. CCSM Meeting June 23-27, 2003 Lower Winter Land Surface Temperatures CAM 2CAM 2.X CAM 2.X – CAM 2

30. CCSM Meeting June 23-27, 2003 Changes in Precipitation CAM2/CLM2CAM2.x/CLM2.2

31. CCSM Meeting June 23-27, 2003 Changes in Coupler & the Sea-Ice Model Coupler –Improved performance and scaling –Greater flexibility to add new fields –Significant DOE communication infrastructure –Faster multi-way communication to components Sea Ice –Horizontal advection scheme –Addition of constant salinity in sea ice –Updates to albedos of snow and sea ice –Updates to ridging for thick ice categories

32. CCSM Meeting June 23-27, 2003 Predicting Co-evolution of CO 2 and Climate Atmospheric GCM Prognostic CO 2 Ocean GCM + BGC Biophysics + BGC International Geosphere-Biosphere Programme C4 Model Iintercomparsion Project Fossil Fuel CO 2

33. CCSM Meeting June 23-27, 2003 Year Month NPP’ [gC/m 2 /yr] LAI’ [m 2 /m 2 ] (-1) x Tmax’ [K] 90W 40N Coupling of NPP and Climate

34. CCSM Meeting June 23-27, 2003 Diurnal Cycle of CO2

35. CCSM Meeting June 23-27, 2003 Major CCSM2 Improvements for Paleoclimate River runoff scheme New sea-ice model Free surface ocean & prognostic cloud water in the atmosphere Grid and ocean/land mapping capability for any past time period Bathymetry and land mask editing tool eCubed. [John Davis and Rick Smith (LLNL); Walter Voit (UT Dallas)]

36. CCSM Meeting June 23-27, 2003 CCSM2 – Holocene Climate CCSM2 Kohfield and Harrison, 2000 Annual Precipitation Change 8.5 ka minus Present mm/year PMIP models underestimated both the north-ward shift and magnitude of the precipitation increase required to maintain lakes and vegetation. CCSM2 more realistically simulates rainfall increases between 20-25°N latitude CCSM2 still underestimates needed rainfall along the Mediterranean and in South Africa. Collaborators: PARCS, PMIP For the mid-Holocene, lake levels, plant macrofossil, and pollen data indicate a greener Sahara.

37. CCSM Meeting June 23-27, 2003 CCSM2 – Last Interglacial Climate Dye 3 Renland Camp Century GRIP     CCSM2 CCSM2 forced with anomalous seasonal solar insolation associated with orbital changes warms the Arctic climate. For summer, Arctic sea ice decreases significantly and Greenland warms by 1-5 o C. Terrestrial data sites warmed rapidly and early; most by 4-6 o C. Greenland ice cap melted except for summit. JJA Surface Temperature 130 ka minus Present

38. CCSM Meeting June 23-27, 2003 The Near Future Tune coupled system over the summer Perform 100-year control simulations Select standard atmospheric dycore Freeze CCSM for IPCC by end of summer Begin documentation of new model Begin research on climate sensitivity, etc.

39. CCSM Meeting June 23-27, 2003 Acknowledgements Jeff Kiehl, for his intellectual leadership and community building Jay Fein and Dave Bader, for their continued support The Working Groups, for their efforts in building a new CCSM Jim Hurrell and Karl Taylor, for their contributions as WG co-chairs Lydia Shiver and Phil Merilees, for their work on the CCSM Science & Business Plans