CPT meeting 20-21 Nov 2003 NCAR Mesa Lab, Main Conference Room NOTE: 1/4 of the scheduled talk times should be reserved for discussion, so if you have 40 mins on the schedule, plan on talking for only 30 mins of that. Thanks to Jeff Kiehl and Stephanie Shearer for organizing the venue and refreshments. ---------------------------------------------------------------------- Agenda Th 20 Nov 0845-0915 Chris Bretherton Welcome and overall CPT meeting goals Session I: Modeling center presentations Goals: Each modeling center should (in no particular order): (1) Discuss the strengths and weaknesses of the cloud climatology of recent versions of the model (2) Critically discuss its cloud, boundary layer, and convection parameterizations, their recent history, and their perceived strong and weak points. Discuss what aspects of model clouds and cloud/radiation feedback are routinely tuned for new model versions. (3) Discuss current in-house efforts to improve model parameterizations relevant to low-latitude clouds. (4) Discuss what is known about the climate sensitivity of recent versions of the model, the cloud feedbacks on climate sensitivity, and what the in-house modelers think is driving those cloud feedbacks in the model. (5) Discuss how your in-house modelling effort will try to make use of the CPT 0915-1030 GFDL model Isaac Held (overall model)/Steve Klein (new PBL) 1050-1205 NCAR model Bill Collins/Jeff Kiehl/Phil Rasch 1205-1315 Lunch (Mesa Lab cafeteria) 1315-1345 Julio Bacmeister GMAO model Session II: Other relevant presentation and core participant plans 1345-1405 Hua-lu Pan NWP experience with cloud simulations and cloud-relevant physical parameterizations at NCEP. 1405-1425 Minghua Zhang NCAR and GFDL cloud simulations results viewed with ISCCP simulator 1425-1445 Joel Norris What can surface cloud observations tell us about cloud variability and feedback on climate timescales. 1445-1515 Coffee break Talks by other core participants each addressing (1) their preliminary scientific plans, esp. for the next year. (2) their anticipated collaborators (3) their readiness (is their budgeted staff hired? Do they need datasets or software tools that they do not have in hand?) (suggestion: 10 mins + 5 mins discussion time) 1515-1530 Bretherton 1530-1545 Marat Khairoutdinov 1545-1600 Cara-lyn Lappen 1600-1615 Brian Mapes 1615-1630 Joel Norris 1630-1645 Robert Pincus 1645-1700 Bjorn Stevens 1700-1715 Kuan-man Xu 1715-1730 Minghua Zhang 1830 Group dinner for those interested. Fr 21 Nov 0830-0850 Norman Loeb, NASA New cloud radiation products and analyses from CERES Session III: Freewheeling discussion on overall CPT strategy 0850-0930 Reaction to previous day's presentations, particularly from advisory panel members. 1. What are the most obvious holes in our strategy? 2. Are there important external collaborations/datasets we should be making more use of? 0930-1030 General discussion on cloud feedback diagnosis strategies: 1. What are the group's favorite physical hypotheses about mechanisms of low-latitude cloud feedback on climate models (e.g. freezing level changes, subsidence rate changes, changes in areal coverage of deep convection, constancy of IR brightness temp. of anvil cirrus, changes in lower tropospheric stability influencing low cloud amount, just to name a few ideas)? We need to be hypothesis-driven to a large extent. 2. Does an initial nonexclusive emphasis on low-latitude low clouds seem appropriate? 3. Is a particular effort on using single-column models and single-column diagnostic approaches appropriate? 4. What other new diagnostic approaches should we be investigating? (e.g. Bony-grams, parameterization swaps in 3D models). 5. Are there diagnostic approaches to cloud feedbacks on climate sensitivity that will allow us to use the satellite data record and in-situ and surface-based data sets to better constrain the cloud feedbacks? 1030-1045 Coffee break 1045-1130 Group discussion on how the CPT should organize to most effectively help to improve cloud-relevant physical parameterizations in the NCAR, GFDL, GMAO models 1. Do we want to set up focus groups, e.g. on subgrid cloud/condensate parameterization, subtropical marine boundary layer cloud processes, clouds and deep convection, etc.? If so, should we have focus group meetings in between annual whole-CPT meetings? 2. Where are we ripe to show improvement in 2-3 years? 3. How should we measure improvement anyhow? 4. Are there datasets out there that we should be comparing with but aren't? 1130-1200 Next steps 1. Next meeting - subgroup or whole group? format? roughly when? External speaker (e.g. LeTreut or Austin to discuss somewhat comparable European and Canadian efforts)? 2. Action items - model run archive, software tools, web page, etc.