State of the CESM. CESM Advisory Board Meeting February Marika Holland CESM Chief Scientist

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1 State of the CESM CESM Advisory Board Meeting February 2013 CESM Chief Scientist Thanks to NSF and DOE for their long-term support of the CESM Project

2 Outline CAB Recommendations from 2012 CESM Planning Community Activities Science Highlights Future Directions

3 CAB Letter Recommendations: March ) Implementation Plan Recommendation for a concise living document 2) Transparency of the climate modeling enterprise For the decision process in development and application activities, etc. 3) Documenting decisions on model optimization/tuning CESM Planning Activities during the last year are addressing these recommendations

4 CESM Planning Activities: Implementation Plan Draft provided: Concise/living document to be updated as needed Outline: 1. Introduction Focused on CESM2; Articulation of best practices/procedures 2. CESM Major Model Releases Definition of what these entail, what we expect for CESM2 (compsets, etc.) 3. Imperatives for future releases Community research tool for studies of climate processes/interactions 4. Development priorities for CESM2 Small scale phenomena in all components and their interactions Improved projections of sea level rise More complete biogeochemical cycles Climate/human system interactions Near-term climate prediction Note that WGs maintain component priorities; More details in revised science plan 5. Timeline for CESM2 6. Model Assessment process (and associated metrics document) 7. Model development process (and associated model release strategy document) 8. Resources and risk management

5 CESM Planning: New Model Release Strategy Pre-set annual release dates with a standard, firm timeline Should ease planning for developments and release resource needs; aid incremental development; provide more consistency Targeting May releases Configurations ( compsets ) in multiple categories Scientifically vetted (with control runs/ climate assessment ) Functionally vetted (routine testing) Development only (no testing; use at own risk) Between releases, compsets can shift categories

6 CESM Planning: Model Validation/Diagnostics Compiling lists of metrics currently in use for component and coupled model assessment Considering improvements to standard diagnostic packages Work underway via CVCWG on coupled model (variability/change) diagnostics package Courtesy of Adam Phillips and Clara Deser

7 CESM Planning: New Model Support Policy Released in November Support Includes bug fixes, script changes, and/or code for time evolution of supported machines Major releases of CESM supported for 5 years after release date or for 2 years after the next major release, whichever period is longer. CCSM3 support expired; CCSM4/CESM1 to 2015 at least

8 CESM Planning Activities: Working Group Process/Procedures By SSC Request, Working Groups are documenting: Priorities for short-term (~yearly) component model developments, including scientific motivation Updated annually after winter and/or summer meetings. The component model development process/protocols, The responsibilities of developers, How decisions are made, etc. Documents to be provided under WG webpages Metrics/diagnostics used for component model assessment Should contribute to a more open and transparent model development and decision making process

9 CESM Planning Activities: Update to Science Plan Mid-way through the existing Science Plan Assessing progress and updating priorities for near-future (next several years) developments (CESM2) Draft should be available within months (by Breckenridge) a) Interaction of the Carbon Cycle, Ecosystems and Climate b) Decadal Climate Projections and Forecasts c) Interaction of Aerosols and Climate d) Interaction of Chemistry and Climate e) Role of the Middle Atmosphere in Climate f) Role of Ice Sheets, Sea Ice and Land in Abrupt Climate Change g) Bounding Future Climate Scenarios h) Simulating Paleoclimates i) Role of Ocean Mesoscale Eddies in Climate j) Interaction with Integrated Assessment Modeling

10 CESM Project Updates/Announcements Redesign of Model Output/Processing Workflow Category CMIP3 CMIP5 Models 2 (CCSM3, PCM) 5 (CCSM4, CESM1-BGC, CESM1-CAM5, CESM1- WACCM, CESM1-CHEM) Volume submitted ~9 TB (over 10 months) ~136 TB (over 1 year) Need to streamline future processing/publishing for large intercomparison projects Need to reduce CESM data storage Maintaining the status quo not possible Effort led by John Dennis (CISL), Jim Edwards (CSEG), Mariana Vertenstein (CSEG)

11 Community Activities

12 Winter Working Group Meetings Ocean Model: January; 48 registered participants Joint/follow on meeting of the CPT on Internal Wave Mixing Atmosphere Model, Polar Climate, Whole Atmosphere, Chemistry Climate: February; 126 Registered participants Follow on meeting on DOE Lab-NCAR CAM development (13-14 Feb) Land Ice: February; 35 Registered participants Societal Dimensions, Land, BGC: February; 83 Registered participants Joint session with Uncertainty Quantification meeting (20-21 Feb) Climate Variability and Change: 4 March, 43 Registered participants Coupling Technologies for Earth System Models (CW2013) held Feb

13 CESM Tutorial Third Annual CESM Tutorial on 30 July-3 August, 2012 Thanks to NSF and DOE for co-sponsoring student participation 80 Participants out of 180 Applicants Involved lectures and practical sessions, requiring a large staff commitment and support from CISL Online tutorial materials available and being widely used Thanks to Dave Bailey for chairing the organizing committee Fourth Annual CESM Tutorial planned for August, 2013 Announcement is out and applications are being accepted We are again targeting about 80 participants Thanks to Susan Bates for chairing the organizing committee

14 CESM Model Releases in Early Feb To enable computing on Yellowstone and Titan and to make new features available to development community cesm1.1.1 (support for new model features) CAM-SE/CAM5 development code base CAM5/CLM4.0 targeted defaults Targeting scientific support for FV 1, FV , 20 th Century and RCP CMIP5 simulations Out of box support for yellowstone, titan cesm1.0.5 (support for CMIP5 science) Out of box support for yellowstone, titan Scientific support for all CAM4 FV CMIP5 simulations ccsm3 (university community request)

15 Community Integrations - Large Ensemble Science Motivation Purpose: To robustly determine simulated natural variability To assess climate extremes and their changing likelihood To investigate detection/attribution of climate changes in the 20 th -21 st centuries From Deser et al., 2012, Nature Climate Change

16 Planned Community Integrations Large Ensemble 30 members (perhaps more) with RCP8.5 forcing scenario CESM-CAM5-BGC (1-degree) with prescribed CO2. Spin-up runs underway; long control will be available Initial state will vary by a round-off level change High-frequency output to be saved Timeslice output for decades in 1850s, 1910s, 1990s, 2070s for downscaling runs Smaller set of continuous daily fields for analysis Thanks to Clara Deser and Jen Kay for leading the planning effort

17 Community Integrations: Last Millennium Ensemble CESM1-CAM5 at 2 o Motivation: only one full forcing simulation with CCSM4 completed for CMIP5 New runs: From ; ensembles of fully-forced + single forcing CESM-CAM5 experiments (23) and fully-forced WACCM runs (2) Serving user-community needs for assessing and attributing regional climate changes

18 Community Integrations High Resolution Control Science Motivation Cubed Sphere Mid-west Spring time propagating systems Regular lat-lon Tropical Cyclones 12-km CAM-SE Run Slide courtesy of Rich Neale

19 Planned Community Integrations High Resolution Control 25km CAM5 coupled to 1-degree ocean Multi-century integration (~200 yrs) Requires CAM-SE configuration Developments still underway Hopeful that CAM-SE with new vertical advection will be released in May, 2013 Integrations unlikely to start until later this year Will solicit community input on experiment design, desired output, etc. Planning will begin after the May release

20 CCSM4/CESM J. Climate Special Collections 43 Papers available via AMS early online release Some additional papers still in review Document major model components and numerous aspects of simulated variability and change

21 CESM as a Community Resource ~450 people with developer level access to code > 600 (unique) Downloads of CESM Tutorial materials >1500 Registered Users of CESM1.0 Participation at CESM Workshop and WG meetings continues to grow

22 Science Highlights

23 CESM (From Hurrell et al., in press, BAMS)

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25 Comparisons of CESM-CAM5 and CCSM4 Example: ENSO Statistics Other aspects: mean state, climate feedbacks, polar change have also been investigated OBS CESM1-CAM5 CCSM4 CCSM3 CCSM4 CESM1-CAM5 CCSM3 Ability to simulate the extended duration of La Nina Events (Courtesy of Adam Phillips and Clara Deser)

26 AIRS 500mb RH MJJA (%) CMIP Analysis Example: Dry Zone Biases and Climate Sensitivity Correlated to ECS TOA SW 21C Intensity of subtropical dry zones in models strongly linked to: Projected cloud trends Reflected solar radiation Model sensitivity R(MJJA RH, ECS) (Fasullo and Trenberth, 2012, Science)

27 CMIP Analysis Example: Dry Zone Biases and Climate Sensitivity CAM5 CAM4 CAM3 (From Fasullo and Trenberth, 2012, Science)

28 CMIP5 Model Intercomparison (Sanderson and Knutti, Assessing large scale climate properties from CMIP5 model projections, in prep)

29 Component Model Intercomparisons Example: CLIVAR WGOMD COREII Experiments AMOC Mean ( ) in Depth Space Courtesy of Gokhan Danabasolgu

30 (From Hurrell et al., in press, BAMS)

31 CESM1 Carbon Cycle Simulations with prescribed emissions and fully prognostic carbon cycle 20C increase in CO2 too large Not enough uptake by land or ocean Documented in: Lindsay et al, submitted, J. Clim Long et al., submitted, J. Clim 20 th Century CO2 Ocean Flux OBS Land Flux OBS

32 Land Model Developments (CLM4.5) Accumulated carbon from losses due to land cover change, gains due to CO2 fertilization regional losses or gains due to climate-carbon feedbacks. Change in Terrestrial Carbon GCP est. (?) More realistic land carbon uptake results from reduced N-limitation on CO2 fertilization. From forced CLM experiments Courtesy of Dave Lawrence

33 (From Hurrell et al., in press, BAMS)

34 Ozone Recovery and Antarctic Sea Ice Response of Antarctic sea ice to fixing ozone depleting substances at 2000 levels relative to RCP4.5 No ozone recovery minus RCP4.5 Ice loss is 33% greater for the ensemble with no stratospheric ozone recovery Suggests that ozone recovery will mitigate Antarctic sea ice loss in the coming decades CESM-WACCM CESM-WACCM Obs Smith, Polvani, and Marsh., 2012, GRL

35 (From Hurrell et al., in press, BAMS)

36 CESM-CISM Integrations Analysis of Greenland Surface Mass Budget Change Average Net Surface Mass Budget Present-day budgets compare well to RACMO (Courtesy of Miren Vizcaino) In 21 st Century: Higher precipitation Larger melt Ablation area increases from 9% to 28% of ice sheet Equilibrium line ~500 m higher SMB increases over 2000m

37 Where We Are Heading Investigation of small-scale phenomena Improved/Enhanced biogeochemical cycles Improved predictions of sea level rise Near-term climate prediction Climate/Human system interactions

38 Current high resolution simulation underway Yellowstone Advanced Scientific Discovery J. Small, F. Bryan, J. Tribbia, R. Tomas, D. Bailey, J. Dennis, A. Baker, J. Edwards, J.Caron, M. Vertenstein, T. Scheitlin, J. Bacmeister Resolutions 25km CAM5/CLM4.0 (spectral element grid) 10km POP2 (62 level), CICE (tripole grid) 1/2 RTM (lat/lon grid) Resolutions allow for resolving ocean eddies and tropical cyclones Performance: ~2 model-years/day on 16,000 processors Target: multi-decade simulations (grand challenge goal) Will help inform other planned simulations C high resolution simulations (Washington et al) Community Integrations 10km POP2 integration with BGC

39 ASD Simulation: 10km ocean and 25 km atmosphere J. Small, F. Bryan, J. Tribbia, R. Tomas, D. Bailey, J. Dennis, A. Baker, J. Edwards, J.Caron, M. Vertenstein, T. Scheitlin, J. Bacmeister SST, Sea ice cover and Sea Surface Height

40 Building a Global, Multi-Scale Ocean Model MPAS supports both quasi-uniform and variable resolution meshing of the sphere. MPAS development is a partnership between NCAR and LANL. high-resolution region Below: Snapshot of kinetic energy from a global ocean simulation with 7.5 km resolution in the North Atlantic. The rest of the global ocean is resolved with a 38 km mesh. The MPAS ocean (MPAS-O) model will be coupled into the CESM over the next year. Slide courtesy of Todd Ringler

41 Community Ice Sheet Model (CISM) Now testing scalable dynamical cores with higher-order ice flow SEACISM dycore with Trilinos solvers BISICLES dycore with adaptive mesh refinement To be included in CISM 2.0, CESM 1.1 Antarctic ice speed, BISICLES model (red = fast flow) Slide courtesy of Bill Lipscomb

42 Model Improvements Targeted at Specific Biases Example: Oxygen Minimum Zone Bias OMZs too extensive in CESM Improvements to Particulate Organic Matter (POM) cycling reduce this bias These are targeted for the CESM1.2 release From Moore et al., submitted, J. Clim

43 New Capabilities Example: Coupling to Data Assimilation Research Testbed New multi-instance model capability Coupling to DART enables: Near-term initialized climate prediction Transpose AMIPtype experiments Courtesy of the DART Group

44 And More All component models incorporating improved parameterizations and processes

45 In summary: Community aspects of the project generally remain strong CESM planning activities are underway to enhance transparency in the model development process and clarify procedures CESM applications continue to increase Model developments and improvements are ongoing We look forward to your advice!