Minutes of the CCSM Scientific Steering Committee
6 July 2004
Eldorado Hotel, Santa Fe, New Mexico

SSC and Ex-Officio Attendees: Bill Collins (Chair), Ben Santer, Cecilia Bitz, Gordon Bonan, Jim Hack, Tom Henderson, Bill Large, Scott Doney, Maurice Blackmon, Jim Carton, Chris Bretherton, Danny McKenna, Jay Fein, Dave Bader, Anjuli Bamzai, Phil Merilees, and Lydia Shiver

CAB Attendees: Ed Sarachik (Chair), Max Suarez, and Isaac Held

Guests: Phil Rasch, NCAR; Don Anderson, NASA; Leo Donner, GFDL; Jeff Kiehl, NCAR; Jean-Francois Lamarque, NCAR; Beth Holland, NCAR; Andrew Gettelman, NCAR; Phil Jones, LANL; Bob Malone, LANL; Peter Gent, NCAR; Byron Boville, NCAR; Peter Hess, NCAR; Natalie Mahowald, NCAR; and Steve Klein, LLNL

1. Welcome. Collins welcomed Anjuli Bamzai, new DOE program manager and ex-officio member of the SSC, and he thanked Maurice Blackmon for his contributions as he rotates off the SSC and also Ed Sarachik as he rotates off the CAB at the end of December 2004.

2. Status of CCSM3 and IPCC Simulations. Collins reported that CCSM3 was released on 23 June 2004, and he showed the control runs and data that are available on the CCSM Web page now and what runs will be available in the future. He also reported that a user's guide, code references, and four Technotes are available on the CCSM Web page.

The plans for the special issue of the Journal of Climate are finished. There will be 29 articles in two volumes, and Collins is negotiating a discount with AMS for the page charges of approximately 10%. John Drake, DOE, Phil Jones, LANL, and Tom Henderson, NCAR, are editing a special issue of IJHPCA to document the software engineering designs and practices used in CCSM3 and other climate models and performance and portability of climate model codes. It will be published in fall 2005.

At the time of this meeting, IPCC scenarios A1B and B1 are nearing completion and there are several other scenarios running at this time. CCSM3 was run on the Japanese Earth Simulator using vectorized code, and the same exact code has been run at NCAR.

Other tasks that have been completed are tuning for multiple resolutions, submitting IPCC results to PCMDI, generating 5700 years of control runs, drafting a new CSL proposal, and much software infrastructure completed, such as revectorization, porting to Linux platforms, and simpler procedures for completion and execution of CCSM3.

Collins reported that the release of the new model was due to great teamwork between CCSM Software Engineering Group, NASA's ESMF group, and DOE's SciDAC group.

Collins reported that he would like to return the future emphasis of the CCSM project to curiosity-driven science development and explanation and exploitation of the new model. He stated the long-term priorities are development of a coupled chemistry climate model and process-oriented modeling of the climate system; next model release will be in 2007 at the earliest; and exploring a single unified CCSM that includes ESMF.

3. Lessons Learned from Development of CCSM. Collins stated that ideally there should be 3 to 4 years between major model releases, the SSC should examine projects and requests that would add to CCSM staff workload, and the SSC should write an implementation plan that will be a road map for the future of the project.

Doney discussed the progress of the Biogeochemistry Working Group to bring together a fully coupled carbon-climate model that includes atmospheric transport, atmospheric chemistry, and land biogeochemistry. Collins reported that Jeff Amthor, DOE program manager, has agreed to move the emphasis of SciDAC-funded software engineers to biogeochemistry and chemistry. ACD's collaborations with CCSM and CGD are progressing, and McKenna's vision is to bring MOZART, or some other chemistry model, into CCSM.

Suggestions for future improvement on experimental design were that more interaction with the Climate Change Working Group is necessary to decide forcing choices and understanding how the model needs to be spun up, decide how to try out new ideas to attack biases when presented by the working groups, and rethink how we diagnose CCSM, especially as a coupled system.

4. Status of CCSP and CCPP. Bamzai reported that the Climate Variability and Change (CVC) charge is to assess high-end models, and Anderson, Fein, and Bamzai have a prospectus document in progress. She also reported that flat budgets are expected for climate.

Regarding CCPP, Bamzai reported that the SciDAC proposals are being renewed, a PI meeting is scheduled for 18 to 20 October 2004, and there is an Announcement of Opportunity from NERSC for computing resources with the proposal due 1 September 2004.

5. Status of ESMF. Anderson reported that there are several ESMF meetings next week at NCAR for all interested agencies to discuss continued funding for ESMF. An Announcement of Opportunity is forthcoming.

6. SGERs. Fein reported that NSF could fund 8 SGERs per year, which is based on CCSM's 8 working groups (excluding software engineering), at $25,000 per grant. There have been 20 to 25 SGER proposals submitted, and each one has been reviewed by the SSC with the criteria being if the proposal is directed toward an urgent need to CCSM. Fein thanked the SSC for reviewing the SGERs, and he said the SGERs have been successful, a good investment, and outreach has been successful.

CMEP (Climate Model Evaluation Project). Fein reported that 18 grants at about $25,000 each are being awarded to university and laboratory scientists for diagnosing model simulations of the climates of the late 19th and the 20th centuries from CCSM, GFDL, and GISS. The awards are jointly sponsored by NSF, NOAA, NASA, and DOE. PCMDI is serving as the model data and observational data archive and distribution center for the PIs. Fein stated that 61 proposals were received and that 18 have been chosen for funding. The proposals are across a wide variety of topics, including both global and regional issues. The PIs will attend an IPCC meeting in March 2005 in Hawaii to discuss their preliminary results. They will produce published papers on their research to be part of the fourth IPCC science assessment.

7. CSL Proposal. The 2004-2005 CSL proposal is due immediately after the workshop, and a draft will be given to each working group for discussion. The working group co-chairs did a great job of proposing exciting new science, and Collins and Merilees thanked the working group co-chairs for their efforts on this proposal. A regional/WRF effort will be housed under the Climate Change Working Group. Some issues were: should we track "major" runs by working groups, should we create a database of runs, and is everyone adhering to the CCSM Data Policy. Collins reported that the CSL targets are a static allocation for all working groups except Polar Climate Working Group, and their allocation will rise. The working group co-chairs will discuss any changes and additions with Phil Merilees before the end of the workshop, so that the CSL proposal can be submitted very quickly.

8. Discussions on Future Directions. Several SSC members and guests gave presentations on future directions for process-oriented modeling of the physical climate system and coupled chemistry/climate modeling.

a. Collins reported on the significant biases found in the coupled and uncoupled models, such as SST in western coastal regions, semi-annual SST cycle, periodicity of ENSO, double ITCZ issue, excessive ice in finite-volume coupled run, continental precipitation biases, and temperature biases.

b. Hack stated that the solution of parameter behavior as a function of model resolution was an overarching goal, and he said some systematic problems are present in the high-resolution (T85) and T42 versions of the model and some get worse at high resolution.

c. Jones discussed the LANL high-resolution ocean and sea ice model that is being developed and that being able to model mesoscale eddies is very important for the biogeochemistry model.

d. Gent discussed the 1/10-degree ocean model that Frank Bryan has been running on the Japanese Earth Simulator, with the goal of running parallel CCSM simulations with 1- and 1/10-degree ocean models. He also talked about the ocean CPTs between NCAR, NASA, GFDL, MIT, Scripps, etc., that are focusing on better parameterizations for the effects of mesoscale eddies and the effects of overflows.

e. Donner discussed parameterization methodologies, such as links between biases and physical processes, improved treatment of cumulus processes, superparameterizations, which is embedding cloud models into GCMs, and the use of assimilation.

f. Klein discussed how physical processes are represented in global models, using statistical methods in CAM to change the macrophysics, using the ISCCP simulator as a tool for cloud diagnosis, effects of boundary layer turbulence, and the use of multiple vertical resolution as an evaluation strategy.

g. Boville discussed future directions for WACCM, which is CAM plus additional physics and chemistry, by exploring the response to solar variability and the use of satellite observations.

h. Hess discussed the need for chemistry and chemical transport models and their role in changes in emissions, biogenic emissions, and aerosols and also meteorological variability, effects of Pinatubo, and biomass burning.

i. Kiehl discussed tropospheric chemistry and climate change and the key future issues to consider, which are ozone (health, air quality, radiative forcing), methane, and greenhouse forcing, aerosols and hydrological cycle (diabatic heating), and coupling to biogeochemistry (deposition).

j. Lamarque discussed the SANTA FE project, which is identifying and studying chemical interactions, such as the impact of nitrogen deposition in carbon uptake during the 21st century; using a variety of climate and atmospheric chemical models to define the range of estimates of interactions; forcing the CLM-CN to estimate the increased carbon uptake; forcing the climate model with updated CO2 concentrations, and repeating experiments in a coupled (land and atmosphere) model (transient simulations).

k. Rasch discussed prognostic aerosols and the areas to be explored, such as direct radiative forcing, photolysis, surface chemistry, and ocean fertilization and process studies for sources of prognostic aerosols, aerosol evaluation, size, and mixtures. A collaborative effort by Rasch, Ghan, Zender, Bond, Wang, Mahowald, and others is under way to explore cloud droplet numbers, dust, polar albedo effects, fossil fuel biomass burning and black and organic carbon, sea salt, etc.

l. Mahowald discussed future chemistry exploration in biogeochemistry by asking five questions that the Biogeochemistry Working Group has stated: 1) what are carbon/climate feedbacks? 2) how do biogeochemical cycles of nitrogen, iron, and sulfur influence carbon/climate feedbacks? 3) how do reactive chemistry and aerosols change and their response to biogeochemistry processes, clouds, and climate? 4) how do land use, land cover change, and water use modify biogeochemical processes? and 5) how do hydrological cycle and biogeochemical cycles interact?

m. Beth Holland discussed future plans for biogeochemistry and stated that Peter Thornton is developing a new land biogeochemical model.

n. Andrew Gettelman discussed the development of codes for stable isotopes in CCSM and their role as natural tracers in the climate system. Ninety percent of the isotope work is being done at universities, and this group needs help to get the codes stable and compatible with CCSM3.

The formation of a chemistry working group was suggested, and the consensus was that this is not the time to do this and that it should be considered again after maturity of the project and if the community is identified and interested. It was also suggested that at next year's workshop a plenary speaker talk about chemistry climate interactions and maybe additional speakers on chemistry climate issues.

9. Software Engineering for CCSM. Tom Henderson discussed the software engineering group's future plans, which are improving robustness, improving planning, continuously improving process that is repeatable and measurable, explicitly identifying tradeoffs, and reducing duplicated efforts and "busy work." Some of the group's strengths are maximizing source code; porting and performance tuning; system testing; automation of configure, build, run, and test; and developing user's guides. A model unification project is under way to address the worst duplicative software engineering efforts and to start gathering requirements of future needs from each working group. Another project is the ESMF acceptance criteria for CCSM that includes no degradation in performance, portability, ease of use, gives the same climate, etc. Sylvia Murphy will be the software engineering group's point of contact for all questions from the community. The group was asked to draft a list of requirements they need from working groups with concrete examples so the working group's and the SE group can communicate better.

10. Meeting adjourned.