ccsm meeting june 23-27, 2003 status of ccsm2.2 bill collins incoming chair, ccsm scientific...

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


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


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


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

http://www.ccsm.ucar.edu/management




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


June 23-27, 2003

Double ITCZ


June 23-27, 2003

Winter Land Surface Temperatures


June 23-27, 2003

Tropical Tropopause Temperatures


June 23-27, 2003

Cloud Forcing Response to Tropical SSTs


June 23-27, 2003

East Pacific Surface Energy Budget


June 23-27, 2003

Tropical Variability


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


June 23-27, 2003

CONTROL All Physics + Numerical MODS

Jan

July

Mixed Layer Depths


June 23-27, 2003

SST Signature of Solar Absorption


June 23-27, 2003

SST Signature of All Ocean Modifications


June 23-27, 2003

New Physics for High Resolution:Anisotropic Mixing


June 23-27, 2003

New Physics for High Resolution:Reduced Lateral Viscosity


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


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


June 23-27, 2003

Increased Reflection of Insolation by Snow

CLM2.2 CLM2


June 23-27, 2003

Increased Turbulent Heat Flux from Vegetated SurfacesCLM2.2 CLM2


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


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


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


June 23-27, 2003

Increase in Cloud Amount, CWP

CAM 2.X – CAM 2 CAM 2.X – CAM 2


June 23-27, 2003

Decrease in Clear-sky Surface Insolation

CAM 2.X – CAM 2


June 23-27, 2003

Cloud Response to Tropical SST Variations

CAM 2.X


June 23-27, 2003

Higher Tropopause Temperatures

CAM 2CAM 2.X

CAM 2.X – CAM 2


June 23-27, 2003

Lower Winter Land Surface Temperatures

CAM 2CAM 2.X

CAM 2.X – CAM 2


June 23-27, 2003

Changes in Precipitation

CAM2/CLM2 CAM2.x/CLM2.2


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


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


June 23-27, 2003

Year

Month

NPP’[gC/m2/yr]

LAI’[m2/m2]

(-1) x Tmax’[K]

90W 40N

Coupling of NPP and Climate


June 23-27, 2003

Diurnal Cycle of CO2


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)]


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.


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


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.


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

ccsm meeting june 23-27, 2003 status of ccsm2.2 bill collins incoming chair, ccsm scientific...

Documents

ccsm science business

stateoftheart model

new pop

status of ccsm2

ccsm2 improvements

chemical processland

minor changes

high resolution