1. Chemistry Climate Modeling of the UTLS An update on model inter-comparison and evaluation with observations Andrew Gettelman, NCAR & CCMVal Collaborators

2. Outline Chemistry-Climate Model Development and Evaluation Process CCMVal, SPARC Tropopause Initiative Upcoming Plans & Evaluations SPARC CCMVal Report & WMO O 3 Assessment Model Diagnostic Development Specific Interactions with START08/HIPPO Note: Chemistry-Climate Model = GCM + chemistry affecting dynamics

3. Chemistry-Climate Science Questions How are the troposphere and stratosphere coupled? Does UTLS chemistry and structure impact surface climate? Where? How? How does the UTLS affect tropospheric composition? How does all this affect stratospheric (UTLS) composition and dynamics (ozone)? Note: Chemistry-Climate Model = GCM + chemistry affecting dynamics

4. CCMVal Chemistry Climate Model Validation (CCMVal) Activity for SPARC (Stratospheric Processes and Their Role in Climate) CCMVal Focus is process oriented assessment Plans Multi-Model Assessments for Stratospheric Chemistry-Climate Models as part of WMO/UNEP Ozone assessments: 19 Model groups involved Involved in IGAC/SPARC `Atmospheric Chemistry & Climate’ (AC&C) initiative to also consider Aerosols (AEROCOM) and Tropospheric Chemistry (TroposChem) (http://www.pa.op.dlr.de/CCMVal/)http://www.pa.op.dlr.de/CCMVal/

5. SPARC Tropopause Initiative The SPARC Tropopause Initiative (SPARC-Trop) is evolving to advance tropopause and UT/LS research: models, observations, etc Develop key science questions Clearinghouse for research & Connecting People http://www.acd.ucar.edu/sparctrop/ (Google sparctrop) http://www.acd.ucar.edu/sparctrop/ A. Gettelman, P. Haynes Coordinators. Seeking interested people!

6. CCMVal / WMO Process Next WMO report expected in 2010 SPARC Assessment Report on Chemistry- Climate Models to be finished by end 2009 UT/LS has a dedicated chapter. Lead Authors: Hegglin (U-Toronto) & Gettelman (NCAR) Model runs going into report will be done in 2008, and analysis in 2008-2009 Goal is process oriented diagnostics (here is where START08 comes in) 2008200920102011 Model Runs WMO Assessment SPARC Report

7. Putting diagnostics together Developing a diagnostic package for global chemistry models through CCMVal NASA ACMAP Funding to develop common model diagnostics Focus on comparison to observations Satellites and In-Situ

8. Key Aspects for START08 Compare interesting analysis to models CCMs and underlying CTMs All CCMs output same format: easy to compare to multiple models Developing a common diagnostic package Would like to include key START08 results in package: data used by all

9. Possible Model Evaluation Contributions STE (Ozone, related tracers) UTLS and Tropopause structure Short lived species distributions UTLS Chemical transport pathways Vertical Profiles in sparsely sampled regions (HIPPO)

10. Evaluating Global Models Using Observations (Pan et al, JGR 2007) WACCM

11. Evaluating Global Models (II) From D. Kinnison/Tilmes Comparison of PDFs in WACCM with: Stratospheric Chemistry (57 Species) Tropospheric Chemistry (115 Species) Ozone in UTLS is similar Polaris and SOLVE WA3, 4x5, 57 species WA3, 4x5, 115 species 115 species 57 species Ozone

12. Evaluating Global Models (II) From D. Kinnison/Tilmes Comparison of PDFs in WACCM with: Stratospheric Chemistry (57 Species) Tropospheric Chemistry (115 Species) Ozone in UTLS is similar CO is better resolved w/ Trop Chem Polaris and SOLVE 57 species 115 species CO

13. Evaluating Global Models III What else have/will we discuss? Double Tropopause Tropopause Inversion Layer Other Tracer-Tracer Correlations Variation by region, events NOx production Gravity Waves

14. Summary UTLS science viewed as key aspect of global chemistry modeling Ongoing international process for model evaluation as part of (a) WMO Ozone reports and (b) related Chemistry-Climate (AC&C) Mechanisms to rapidly get interesting results from field observations into model evaluation Also: multi-model ensembles make it easy to use model output for comparison to observations START08 & HIPPO Can contribute! Talk to your friendly neighborhood modeler!