_______________________________________

SPARC CCMVal Chapter 6:Stratospheric Chemistry and Microphysics

_______________________________________

Lead Authors: Martyn Chipperfield and Doug Kinnison

Co-Authors: Slimane Bekki, Huisheng Bian, ChristophBruehl, Tim Canty, Sandip Dhomse, Lucien Froidevaux,Lynn Harvey, Rolf Muller, Michael Prather, CoraRandall, Ross Salawitch, Michelle Santee, WenshouTian, Simone Tilmes

CCMVal WorkshopToronto, Canada, June 2009

Posters Presentations for Chapter 6

• CCMVal Model Evaluation of Heterogeneous Processes in the Polar LowerStratosphere: Tilmes et al.

• Satellite stratospheric measurements from the 1990's to now: Data and models:Froidevaux et al. (was an oral).

----------------------------------------------------------------------------------------------• An approach for evaluating long-term changes in the chemical cycles affecting the

ozone budget: Bodeker, Struthers, and Smale.• ACE-FTS climatological dataset for model comparisons: Jones et al.• Present-day climatology of a new coupled chemistry-climate model CNRM-ACM

: sensitivity to horizontal resolution, meteorological parameters and coupling:Michou et al.

• A global inventory of stratospheric NOy from ACE-FTS measurements: Qin et al.• Halogen emissions of major volcanic eruptions: a new approach using the

petrologic method and CCMs: Toohey et al.

Oral Presentations for Chapter 6

• Upper stratospheric ozone temperature correlations; impact ofchanging chlorine: Stolarski et al.

------------------------------------------------------------------------------• Reactive nitrogen, hydrogen and chlorine species and

stratospheric ozone in the CCMVal2-models and constraints bysatellite data Bruehl et al.

• Comparison and evaluation of the photolysis rates used instratospheric chemistry models -- PhotoComp 2008: Bian,Prather, Chipperfield, Kinnison

• Evaluation of fast chemistry using PSS model, Salawitch, Canty,Johnson, et al.

Chapter 6 Model Output Needed.

• Several CCMs have contributed REF-B1 T3I fields. Theses fieldsare used in the majority of analysis conducted in Chapter 6.Currently we have output from 9 (out 18) CCMs:

CAM3.5, CCSRNIES, CMAM, CNRM-ACM, GEOS-CCM,MRI, UM-SLIMCAT, UMUKCA-METO, and WACCM.

• Out of these 9 models, we also only have T3I Surface areadensity fields (e.g., Sulfate, NAT, ICE) from 3 of these models(REF-B1).

• REF-B2 T3I fields? [Tracer-tracer ozone loss approach – morelimit number of species (T, U, V, O3, N2O, Cly, ClOx)].

Photocomp 2008 Benchmark

• We need all models to complete the 2008 Photocomp. Currently the followingCCM groups have submitted results:

Chapter 6 FOD Outline

1. Introduction

2. Formulation of Chemical and Microphysical Schemes [move to chapter 2?]

3. Evaluation of CCMs1. Photolysis Rates [oral]2. Fast chemistry [oral]3. Long-lived Species [oral]4. Polar Chemistry [poster]

4. Summary

Status and Reviewers Comments

“The chapter needs some re-structuring. I suggest that the introductionis followed by a section on ‘Diagnostics and observations’ thatprovides an overview of all diagnostics and observations used in thechapter.”

“This will give the reader a bit more guidance. A detailed motivationwhy these diagnostics (and not others) have been chosen will need tobe included in this section and it would benefit from a table similar tothe CCMVal evaluation table for the chemistry diagnostics.”

“The table should also provide a ranking of the importance of thechemistry diagnostics for ozone in different altitude and latituderegions. This ranking is also required for the yet missing section onperformance metrics.”

Photocomp 2008

“Better description of CCMval Model approaches (LUT, etc…)” – thiscould/should be handled in chapter 2?

“Reading through this for the first time, I found working through thecomparison a tough slog” - will attempt to make this an easier read!

“Define metrics; rank models.” – need to define these.

We should also connect results from this diagnostic with the PSSmodel fast chemistry diagnostic!

Fast Chemistry Diagnostic

“This section promises to very interesting…” – there was just oneexample given in the FOD. Ross Salawitch will give a detailedoverview later today!

We have only used this approach for 1993 conditions (REF-B1). Weshould also examine a volcanically clean period.

We need to compare this to the Photocomp results and radicalscompared to satellite observations (e.g., MIPAS data; see Bruhl et al.).

Metrics / grading needs to be defined.

Long-lived Species

“The chapter on comparison to satellite climatologies is very draftyand is planned to provide some comparison of reservoirspecies to satellites. The stamp like plots, which are includedcurrently would serve as a possible supplement since theyprovide information in a traditional way, which allows for qualitativecomparison. I suggest to include higher evaluated analysis in the finalversion” – A more concise approach will need to be shown. Possiblywe could have a supplement document or webpage where “post-stamp” figures can be shown?

We should also make sure we are not duplicating efforts here that havebeen shown in other chapters where long-lived tracers are used forTransport and Dynamics diagnostics.

Polar Chemistry

“Evaluation of Polar Chemistry: The comparisons against MLS forchlorine activation (ClO and HCl), denitrification (HNO3) anddehydration (H2O) should be very interesting. Not too much tocomment on at the present time. ” – See poster. We have convertedCCMVal output to Eqlat / theta coordinate system for comparison toMLS observation. We need T3I output from each CCM.

We will create metrics for these processes and attempt to connect it tothe ozone loss approach that Simone Tilmes is deriving (tracer/tracerapproach – see poster).

Lucien Froidevaux will make the MLS data available to CCMVal.

Next Step: Moving Towards the SOD

• Chapter Meeting (Thursday)!

• Finish analysis of all the CCMs by 1 July [assuming current 1 AugSOD deadline].

• Better define each metric and grade each model for each metric.

• Create a Chpt 6 Synthesis Summary.

• Add Chpt 6 Executive Summary.

• It would be very helpful for Chapter 6 to have the SOD due date bemoved to 15 Sept. 2009 [if so final model results would be due nolater than 15 Aug. 2009].

Chapter 6 Outline

1. Introduction

2. Brief Information on Chemical and MicrophysicalSchemes [if not in Chapter 2]

3. Description and rationale for diagnostics; description ofobservations used; table of diagnostics

4. Evaluation of CCMs (with metrics)1. Photolysis Rates2. Fast chemistry 3. Long-lived Species 4. Polar Chemistry5. Future Chemistry?

5. Summary (include metric ‘bar chart’)

Chapter 6 Drafty SOD Outline

Chapter 6 OutlinePossible Metric Summary Bar Chart

Fast (radical) photochemistry

Photolysis

Source gases / reservoirs

Polar chemistry

Individual metrics (3 or 4 per category) can feed into 4 topics: