CCSM Chemistry-Climate Working Group

Meeting Report

Monday, 20 June 2005
The Village at Breckenridge

The CCSM chemistry-climate working group held a full day planning meeting on June 20 at Breckenridge. Twenty-five people attended the meeting.

The meeting consisted of the following components:

1. We reviewed the basic responsibilities and obligations of the working group and the available resources. At present the working group has 1/3 FTE.
   
2. We reviewed the current CCSM3 capability in terms of atmospheric chemistry and discussed the development modules involving atmospheric chemistry. P. Rasch discussed the current released CCSM modules and their capabilities. In particular the finite volume dynamical core was emphasized. Peter Hess reviewed the status of chemistry within CAM. Three separate chemical capabilities exist: in WACCM (Whole Atmosphere Community Climate Model) extending to 140 km, in MACCM (Middle Atmosphere Community Climate Model) extending to approximately 80 km, and in the tropospheric model extending to 35 km. These components can be run either online, where the winds are generated internally within the model, or offline, where the meteorological fields are imported from other sources. P. Hess reviewed the current state of the tropospheric chemistry model, planned development for the immediate future and future development needs.  D. Kinnison reviewed the middle and upper atmosphere model components, including a review of the heterogeneous stratospheric chemistry included in the model.
   
3. Thirteen working group attendees gave short presentations on relevant science issues or examples of interaction with CCSM.
   
4. We identified the key science areas in which atmospheric chemistry played an important role and which appeared likely CCSM future research areas. We had extensive discussion on these science areas (each of which could be the umbrella for several specific projects) and which would be high priority on basis of timeliness, science urgency, and especially needed development for CCSM4.  A straw vote was cast to determine the top 4.

The top four areas (in no particular order) are:

a)      Chemistry and transport in Convection-Cloud-Rain parameterizations
b)      Aerosol effects on Clouds, Energy and the Hydrologic cycle
c)      Hemispheric pollution to regional air quality
d)      Multiple stresses on the land-biosphere

Basic priority research areas (in no particular order) are:

e)      Stratosphere – troposphere coupling
f)        Sun – climate connections
g)      Atmospheric chemistry in the carbon cycle
h)      Cryosphere – chemistry coupling
i)        Paleo – atmospheres.

It is clear that the inclusion of atmospheric chemistry will necessitate requirements from other CCSM modules. This addresses new/corrected capabilities with respect to CCSM3 and we expect will require coordinated development with other components of the model. We have an action item to list these. Examples include requirements of microphysics, convection (deep and shallow), radiation etc.

ATTENDEES:

Philip Cameron-Smith, Lawrence Livermore National Laboratory
Carrie Dean, Los Alamos National Laboratory/UCCS
Sumner Dean, Los Alamos National Laboratory
Louisa Emmons, NCAR
David Erickson, Oak Ridge National Laboratory
Andrew Gettelman, NCAR
Steven Ghan, Pacific Northwest National Laboratory
Peter Hess, NCAR
Trond Iversen, University of Oslo
Lyatt Jaegle, University of Washington
Jeffrey Kiehl, NCAR
Douglas Kinnison, NCAR
Jean-Francois Lamarque, NCAR|
Natalie Mahowald, NCAR
Loretta Mickley, Harvard University
Athanasios Nenes, Georgia Institute of Technology
Joyce Penner, University of Michigan
Michael Prather, University of California - Irvine
Philip Rasch, NCAR
Diandong Ren, University of Oklahoma
Fabrizio Sassi, NCAR
Owen Toon, University of Colorado
Francis Vitt, NCAR
Stacy Walters, NCAR
Donald Wuebbles, University of Illinois at Urbana-Champaign