Chemistry Climate Modeling of the

UTLSAn update on model inter-comparison and

evaluation with observations

Andrew Gettelman, NCAR & CCMVal Collaborators

Outline

•Chemistry-Climate Model Development and Evaluation Process

• CCMVal, SPARC Tropopause Initiative

•Upcoming Plans & Evaluations

• SPARC CCMVal Report & WMO O3 Assessment

• Model Diagnostic Development

•Specific Interactions with START08/HIPPO

Note: Chemistry-Climate Model = GCM + chemistry affecting dynamics

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

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/)

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)

• A. Gettelman, P. Haynes Coordinators. Seeking interested people!

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)

2008 2009 2010 2011

Model Runs WMO Assessment SPARC Report

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

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

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)

Evaluating Global Models•Using Observations (Pan et al, JGR 2007)

WACCMWACCM

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 species115 species

57 species

Ozone

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 similarCO is better resolved w/ Trop Chem

Polaris and SOLVE

57 species

115 species

CO

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

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!