Chemistry-Climate Working Group Meeting (March 22-24, 2006) Background –SSC expectations and the next IPCC (Bill Collins) Summarize where we are now Discuss where we are going Discuss meeting goals

CLM (land model ) POP (Ocean Model) CICE (Sea Ice Model) 35 km (26 levels) Tropospheric CAM with chemistry CAM with Chemistry 140 km (66 levels): Whole Atmosphere Community Climate Model (WACCM) 80 km (52 levels): Troposphere and stratospheric CAM with chemistry (MACCM) Unified Global Modeling Framework Ion Drag Chemical Heating PSCs Volcanic Aerosols Trop. Aerosols HydroCarbon Chemistry

Current Progress CAM-chem: Tropospheric chemistry climate model (species concentrations specified in the stratosphere) –On and Offline modes available –Checked into development branch of CAM –Most recent MOZART chemistry included MOZART aerosols Wet Deposition: Giorgi and Chameides Dry Deposition: Wesley Photolysis: FTUV, or Lookup table Megan Emissions Preprocessor and MOZART chemistry

Current Progress WACCM: Whole atmosphere version of CAM (0-140 km) –In separate branch of CAM –Offline version in development –Planned release in 2006 MACCM: Middle atmosphere version of CAM –Plans are to develop this from WACCM –It will probably reside in the WACCM branch of the code

Working Group Tasks -To build, maintain and document chemistry/aerosol components of the CCSM Default version for IPCC studies Chemistry version Others -Recommend to the CCSM Scientific Steering Committee (SSC) new model development Give range of options with costs for various model components and benefits of each; give a recommendation as to the best option Justify recommendation in terms of climate impact, needs of other working groups, plus.... -Plan present and future scientific and model experiments

Resources (1/3) Software Engineer Gaus: 100 simulation years per month using full chemical mechanism (Allocation of resources: If you want support through the WG send me a short 1 page description of: proposed work, simulations, resources requested, relevance to the working group)

Top four science areas: priority assigned on basis of timeliness, science urgency, needed development for CCSM4. Aerosol effects on Clouds, Energy & Hydrologic Cycle Photochemistry & scavenging in clouds, convection, rain. Hemisphere/regional air quality (link to WRF) Land biosphere response to multiple stresses (water, PAR, ozone, nitrate) Other key science areas. Stratosphere - Troposphere coupling Sun - Climate connections Paleo-atmospheres Atmospheric Chemistry links to ocean BGC Cryosphere - chemistry coupling 1 st Chemistry-Climate WG Planning Meeting 20 June 2005

-Aerosol effects on Clouds, Energy & Hydrologic Cycle (wp) -Photochemistry & scavenging in clouds, convection, rain. -Hemisphere/regional air quality (wp) -Land biosphere response to multiple stresses (water, PAR, ozone, nitrate) (wp) -Domain (not included in planning meeting) -Reactive Mechanisms (not included in planning meeting) -Emissions (not yet addressed) For each area we need a recommendation for the SSC. To many areas, too few? Areas to be discussed at this workshop

Meeting Goals For each area identify range of possible implementations. Identify who is working on what. Do we have adequate representation? Identify holes and priorities. Endorsement of approach in white-papers

Number of Models to Maintain as a Working Group Climate model with chemistry State-of-the-art Chemistry -Transport Model Earth system model How many is too many? How many chemical mechanisms? Different vertical domains?