Update on CCSM Project

1
Update on CCSM Project

• Bill Collins
• National Center for Atmospheric Research
• www.cgd.ucar.edu/wcollins

2
CCSM Status

• Next release is named CCSM3.
• Public release target date June 2, 2004
• Contents of public release
• Source code (same as for IPCC integrations)
• Documentation
• Run environment
• Model integrations
• Support IBM, Linux, Cray, NEC, SGI, Compaq

3
Atmospheric Dynamics and Resolution

• Goal for IPCC T85 (1.4o) or equivalent FV
  resolution
• Improved resolution for regional impact studies
• Improved resolution for fidelity in coastal
  stratus regions
• Recommendation on atmospheric dynamics
• Eulerian for standard IPCC scenario applications
• Finite Volume for future development and
  experimentation
• Goal for CCSM Single physics package for
  multiple dynamics resolutions

IPCC
AMWG, CVWG, Paleo,
Resolution
BGCWG, Paleo
Dynamics
4
The IPCC Integrations

• Three phases
• Pre-industrial (1870)
• 20th Century (1870-2000)
• Emissions Scenarios (2000-2200)

5
Timeline for IPCC Integrations
6
Surface Temperatures 1870 Integration
7
TOM Energy Balance 1870 Integration
8
Special Issue of J. Climate

• Goal Document basic features of
• coupled model
• coupled climate
• All WGs have been asked to contribute.
• Schedule
• IPCC Paper submission by May, 2005.
• Submission deadline November, 2004
• Note Many papers to appear elsewhere!

9
Special Issue of J. Climate (II)

• Core papers
• Overview of CCSM
• Description of features climate state for each
  component
• Climate sensitivity
• Response of CCSM to paleo, pre-industrial
  conditions
• Major modes of coupled variability
• WG papers
• Papers from all WGs except SEWG BGCWG
• 35 papers proposed list will be refined by SSC

10
CCSM Integrations
11
Surface Temperatures 1990 Integration
12
Sea-Ice Extent 1990 Integration
13
The CO2 Bug

• CO2 is used in two forms in CCM/CAM
• Volume mixing ratio (co2vmr) GH effect of CO2
• Mass mixing ratio (co2mmr)
• Overlap of CO2 and CH4, N2O, and CFC-11/12
  absorption
• Absorption of near-IR solar radiation by CO2
• The problem
• co2vmr f(t)
• co2mmr ? f(to)
• Manifestations 1CO2/yr integrations

14
The CO2 Bug

• Magnitude of the problem

-2.89
-2.46
-3.56
-3.13
TOA
Tropopause
BUG
0.09
0.0
-0.65
-1.57
Surface
Shortwave
Longwave
Shortwave
Longwave
15
Special Issue of J. Climate (III)

• Author categories before public release
• Principal developers
• Close collaborators
• Principal developers
• Core SSC, WG co-chairs liaisons, CSEG
• Others added by WG co-chairs and SSC chair
• Full access to model data and code
• Close collaborators
• Individuals may apply to Tony Craig to be added.
• Individuals must agree to terms for access.
• Data code are provided only for paper writing
  or collaborative projects with Principal
  Developers.

16
Plans for the (Near) Future

• Grand challenge experiments
• Next CSL proposal due in summer 2004
• My goals for 2005
• Roadmap to the future
• 1st Generation Chemistry-Climate Model
• Biogeochemistry
• Isotopes H2O and possibly CO2
• WACCM chemistry for stratosphere-thermosphere
• Reactive chemistry in the troposphere
• Prognostic aerosols sea salt, dust, carbon,
  sulfate, nitrate