CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Status of CCSM2.2
Bill CollinsIncoming Chair, CCSM Scientific Steering
CommitteeNational 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
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Development Plans for CCSM, 2004-08http://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
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Double ITCZ
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Winter Land Surface Temperatures
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Tropical Tropopause Temperatures
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Cloud Forcing Response to Tropical SSTs
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
East Pacific Surface Energy Budget
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Tropical Variability
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
CONTROL All Physics + Numerical MODS
Jan
July
Mixed Layer Depths
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
SST Signature of Solar Absorption
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
SST Signature of All Ocean Modifications
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
New Physics for High Resolution:Anisotropic Mixing
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
New Physics for High Resolution:Reduced Lateral Viscosity
CCSM Meeting June 23-27, 2003CCSM 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
SnowMelt
Sublimation
ThroughfallStemflow
Infiltration Surface Runoff
Evaporation
Transpiration
Precipitation
Soil Water
Redistribution
Direct Solar
Radiation
Absorbed SolarRadiation
Diff
use
Sol
ar
Rad
iatio
n
Long
wav
e R
adia
tion
Reflected Solar Radiation
Em
itted
Lon
g-w
ave
Rad
iatio
n
Sen
sibl
e H
eat
Flu
x
Late
nt H
eat
Flu
x
ua0
Momentum FluxWind Speed
Soil Heat Flux
Heat Transfer
Pho
tosy
nthe
sis
Biogeophysics
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Increased Reflection of Insolation by Snow
CLM2.2 CLM2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Increased Turbulent Heat Flux from Vegetated SurfacesCLM2.2 CLM2
CCSM Meeting June 23-27, 2003CCSM 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
CLM2.2 CLM2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Long-Term Development Tasks
Task Scientific Lead
PhysicsExcessive interception Guiling WangEfficient leaf temperature algorithm Guiling WangCanopy storage of heat,moisture, CO2 Scott Denning, Ian BakerSunlit/shaded canopy Peter ThorntonSnow hydrology Zong-Liang Yang, Guo-Yue NiuRunoff Zong-Liang Yang, Guo-Yue Niu2-m temperature over grass Robert DickinsonSurface albedos Xubin Zeng, Robert Dickinson
BiogeochemistryTerrestrial carbon cycle Peter ThorntonWater isotopes Natalie Mahowald, David NooneMineral aerosols Natalie Mahowald, Sam Levis
Land Cover ChangeAgroecosystems Gordon Bonan, Johan Feddema, Keith OlesonUrban land cover Gordon Bonan, Johan Feddema, Keith OlesonPrognostic biogeography Sam Levis, Gordon Bonan
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Increase in Cloud Amount, CWP
CAM 2.X – CAM 2 CAM 2.X – CAM 2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Decrease in Clear-sky Surface Insolation
CAM 2.X – CAM 2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Cloud Response to Tropical SST Variations
CAM 2.X
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Higher Tropopause Temperatures
CAM 2CAM 2.X
CAM 2.X – CAM 2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Lower Winter Land Surface Temperatures
CAM 2CAM 2.X
CAM 2.X – CAM 2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Changes in Precipitation
CAM2/CLM2 CAM2.x/CLM2.2
CCSM Meeting June 23-27, 2003CCSM 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
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Predicting Co-evolution of CO2 and Climate
Atmospheric GCMPrognostic CO2
Ocean GCM+ BGC
Biophysics+ BGC
• International Geosphere-Biosphere Programme C4 Model Iintercomparsion Project
Fossil FuelCO2
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Year
Month
NPP’[gC/m2/yr]
LAI’[m2/m2]
(-1) x Tmax’[K]
90W 40N
Coupling of NPP and Climate
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
Diurnal Cycle of CO2
CCSM Meeting June 23-27, 2003CCSM 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)]
CCSM Meeting June 23-27, 2003CCSM Meeting
June 23-27, 2003
CCSM2 – Holocene Climate
CCSM2
Kohfield and Harrison, 2000
Annual Precipitation Change8.5 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.
CCSM Meeting June 23-27, 2003CCSM 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 1-5oC.
• Terrestrial data sites warmed rapidly and early; most by 4-6oC.
• Greenland ice cap melted except for summit.
JJA Surface Temperature130 ka minus Present
CCSM Meeting June 23-27, 2003CCSM 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.
CCSM Meeting June 23-27, 2003CCSM 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