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Chemistry-Climate Working Group Meeting (March 22-24, 2006)

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. Unified Global Modeling Framework. CAM with Chemistry.

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Chemistry-Climate Working Group Meeting (March 22-24, 2006)

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  1. 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

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

  3. 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

  4. 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

  5. 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

  6. 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)

  7. 1st Chemistry-Climate WG Planning Meeting 20 June 2005 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

  8. Areas to be discussed at this workshop -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?

  9. 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

  10. 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?

  11. Discussion • How many models to maintain? (chemical mechanisms, domains etc) • Is our list of areas reasonable?

  12. White Papers -> At end add criteria for proposed models: metrics

  13. Summary Microphysics Aerosols Chemistry 1. Simple 1. Simple 1. oxidants 2. Complex 2. S Ghan 2. Reduced (2m4c) (reduced) mechanism (includes nitr.) 3. S Ghan Full (7 mode) Mechanism (testing) Carma (testing ?)

  14. Summary Wet Deposition Current With S. Ghan’s aerosols -> addition capability (impact scavenging?) Wet Deposition within convective scheme? (advocate for a scheme?) Wet Deposition of gaseous species

  15. Aerosols • Direct and indirect effects using diagnosed aerosols • Range of aerosol options (bins, modes, mixtures) • Chemistry options • Oxidants input into model • Current formulations do not include SOA, NH4NO3 • Can we justify their importance? • Should we pursue simple mechanisms to include SOA, NH4NO3 ? • Simple chemistry • “Full” chemistry

  16. Biogeochemistry • Chemistry Options • Nitrogen input into the model • Is it valid to include nitrogen and not ozone? • Ozone and nitrogen input into the model • Interactive chemistry

  17. Vertical Domain • Importance of a stratosphere vs cost of stratospheric chemistry • To what extent should we pursue MACCM, simple stratospheric chemistry?

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