[an error occurred while processing this directive] [an error occurred while processing this directive]

Minutes of the CSM Scientific Steering Committee (SSC)

Thursday, 6 January 2000

NCAR, Director's Conference Room


Attendees: Maurice Blackmon (Chair), Jay Fein, Anjuli Bamzai, Dave Randall, Dick Moritz, Bob Dickinson, J. Shukla, Susan Solomon, Peter Gent, Jeff Kiehl, Frank Bryan, Byron Boville, and Lydia Harper

1. Blackmon welcomed the SSC members. He thanked Solomon, Dickinson, and Boville for agreeing to another two-year term on the SSC. He also thanked Bryan for his service on the SSC, and he welcomed Moritz as Bryan's replacement on the SSC.

2. The CSM Data Policy was finalized and approved for publication on the CSM website (http://www.cesm.ucar.edu/experiments/datapolicy.7jan00htm). Appropriate references and acknowledgments of CSM data are requested.

3. The NCAR Code Assessment Report and Response was discussed by Blackmon and the SSC members. It was reported that ECMWF has developed techniques that give better performance. Blackmon and others will visit ECMWF, Hadley Centre, and CDES (Toulouse, France) to discuss their software engineering techniques and how CSM can show better performance.

4. Blackmon reported on the CSM Advisory Board Meeting that took place on 30 November 1999 at NSF in Washington, DC. At that meeting it was reported that the CSM and the Parallel Climate Model (PCM) would merge in the near future. The ocean model will include the K Profile Parameterization (KPP), the Gent-McWilliams scheme, and the Visbeck et al. parameterization. A high-resolution CSM model will be included in the CSM framework and will be used for climate assessment and IPCC studies.

5. Blackmon reported on the status of the CSM Working Groups. Elizabeth Hunke replaces Bill Large as co-chair of the Polar Climate Working Group while Large is on sabbatical. Lisa Sloan joined the Paleoclimate Model Working Group as co-chair. Shukla will step down as co-chair of the Seasonal-to-Interannual Working Group (SIWG) after the 5th Annual CSM Workshop in June, 2000.

The SSC approved the formation of the CSM Climate Change and Assessment Working Group as soon as possible. The co-chairs will be Warren Washington, Jerry Meehl, and Ben Santer. Appointment letters will be sent to the co-chairs.

It was recommended that the future role of chemistry and chemistry modeling in CSM be discussed at the June SSC meeting. It was also recommended that discussions be held with the new ACD Director about these issues.

6. Al Kellie and Pete Peterson, SCD, joined the meeting to discuss NCAR computing now and in the near future. On 1 March 2000 the CSL resources will be 24,400 GAUs per month, on 1 May 2000 the CSL is expected to increase its resources to 58,200 GAUs per month, and 1 December 2000, the CSL is again expected to increase its resources to 134,300 GAUs per month. The types of machines are not known but the CSL resources will increase. For the CSL proposal, each proposal must include how many GAUs could be used per month from 1 March 2000 to 29 February 2001 using the information provided by SCD. Another issue for the CSL proposal is the Mass Storage System (MSS) charges. SCD is trying to control growth of the MSS and will use a different charging method for the CSL in 2000.

7. The schedule for CSM 2.0 was discussed, and the goal is to complete development of CSM 2.0 by December, 2000, and to begin a long (1000 year) control simulation then. CSM 2.0 would then be released before the June, 2001, CSM Workshop. The atmosphere component will be CCM4. The ocean model (POP) is in progress and ocean-alone and ocean-sea ice coupled runs should be completed by June, although the equilibrium runs will not be completed by June. The sea-ice model version 2.0 will be ready before either the atmosphere or ocean model, so hopefully more work can be included on implementing explicit melt ponds, implementing lateral/basal melt, adjusting snow conductivity, simulating sensitivity to ocean heat flux and wind stress, etc. The land model point processes and scalability are being worked on, Fortran interfacing to CSM is a problem to be solved, and land cover will be implemented by Gordon Bonan. Tom Bettge will be asked to chair a joint PCM/CSM group of software engineers to consider redesigning the flux coupler. We hope to develop a scalable version that allows either concurrent execution of the component models on separate processors (as in CSM 1.0) or sequential execution on the same processors (as in PCM).

8. Bamzai reported on the status of FY99 one-time funds. In general, these grants have been fairly successful in making advances, both in model development, as well as diagnostic studies involving the CSM.

PI Bradley's grant is being used to support Caspar Ammann's ongoing work related to the inclusion of stratospheric aerosol in the NCAR Column Radiation Model (CRM) and the Climate Community Model (CCM), as well as preparation of a historical aerosol forcing data set. PI Denning is working on a set of standard numerical experiments, TransCom2, to evaluate the realism of the trace gas transport, specifically SF6, in CCM3. PI Waliser's grant is supporting a graduate student who is analyzing the TOVS Pathfinder data to provide observational variability associated with the life cycle of the MJO and compare this observational description to those depicted by NCAR CCM2 and CCM3 simulations. Three grants (PIs Steele, Proshutinsky, and Zhang) are for research on the sea-ice model in the CSM. The award to Steele supports Cecilia Bitz for ongoing work on a new ice thickness model, chosen by the SSC as the base model for the next version of CSM. Proshutinsky's award is supporting a student to examine the ability of the CSM to simulate the Arctic oscillation. Zhang has implemented his new model into the CSM, and results of a multi-year run were presented at the CSM Workshop last summer. PI Nigam has been conducting diagnostic studies of the CCM3 and CSM. He has, with Dave Randall's input, proposed to the CSM Atmosphere Model Working Group, an expanded list of variables needed to comprehensively monitor the model's performance with respect to various modes of climate variability. Finally PI Wang, whose award was made later than the others, is conducting diagnostic analyses of the NCOM model.

Fein stated that one-time funds of small grants are available again for university collaborators for CSM start-up projects; however, he stated the SSC should give their recommendations subject to the consideration that the proposed work was ready to be carried out by the PIs in a timely way. An announcement or information should be distributed about this funding opportunity at the 5th Annual CSM Workshop.