Update on AMWG/CAM Activities Phil Rasch

1. Update on AMWG/CAM ActivitiesPhil Rasch • Report on last meeting & where we are going • Answer questions • Focus over last year on reducing systematic biases in CAM/CCSM • I view the last years effort as extremely successful, and am very optimistic about accomplishments over the next year • Working group web page http://www.ccsm.ucar.edu/working_groups/Atmosphere • Talks from last meetinghttp://www.ccsm.ucar.edu/working_groups/Atmosphere/Agendas/amwgmeetingagenda2006Jan.html • WIKI at http://swiki.ucar.edu/cam-dev (contact Andrew Gettelman for access)

2. What was discussed • Convection, Convection, Convection, …. • PBL and Shallow convection • Polar Clouds • Gravity Wave Drag • Aerosols & Microphysics • Diagnostics • extratropical cloud/cyclones • Extratropical dynamics • CAPT • Dynamical Cores • Data Assimilation • See http://swiki.ucar.edu/cam-dev for developments in these areas (contact Andrew Gettelman for passwords if you need one)

3. What was missing • Cloud fraction, subgrid variability, cloud overlap, independent column approximations • Gravity Wave Drag • Flow dependent horizontal diffusion (e.g. Smagorinsky) • Microphysics within vigorous convection • Radiation • Extra-terrestrial CAM • New grids/numerical techniques for CAM • HOMME • Conservative remapping

4. What is happening in other components of CCSM • Software engineering efforts relevant to the development of CCSM • Subversion repository maturing • Sequential CCSM development (significant refactoring of CAM as first stage. No re-griding yet) • Removed dependencies within CAM assuming rectangular lat/lon grids (opens path for cubed sphere and triangular grids) • Coupling Frameworks: We plan to exploit two frameworks • Much of the development has been done using MCT • Nearing complete ESMF capability. Stage 1 effectively complete. Stage 2 begins. • Unification of FV core with NASA GEOS-5 modeling effort • Fixed OMEGA (pressure velocity) in CAM • Much improved regression testing procedures for CAM, constantly evolving, to exercise new functionality • Database of experiments and control simulations (currently most relevant for CCSM rather than CAM) • Tropospheric MOZART/Chem, WACCM, UW Physics, Emanuel convection, Offline CAM & CGD aerosols on development trunk as options • Massively parallel issues [I/O, dynamical core, memory (particularly lookup tables in chemistry)]

5. Feb 27-28 What is happening in other components of CCSM part II • Exploratory • Regional Cloud Resolving Model (NRCM, WRF run in a channel driven by either analyses or CCSM) • The path forward • New land model (revisions to hydrology) • Chemistry [w/aerosols (simple and more complex)] • More Biogeochemistry • (Carbon, Nitrogen cycles) • C4MIP -> C-LAMP(compare CASA, CN, IBIS w/in SciDAC) • Substantially revised ocean model (POP-2 code, vertical resolution, horizontal viscosity, GM modifications, new advection) • New Sea Ice Model (CSIM -> CICE4, ridging, albedo, meltponds)

6. Interim model (CCSM3.5) • Will combine all model component improvements available as of about 1 March, 2007 • Goal to allow exploration of Carbon Cycle early in the evolution of CCSM4 (spinups of as much as a thousand years are necessary to equilibrate biogeochemical models) • Strategy is starting to evolve to produce controls for the CC experiments • Balance CCSM at TOA at 1870 conditions • Run model forward in time with transient forcing, look at present day simulation to make sure it looks like today’s planet earth. • Iterate until physical system acceptable • Start BGC simulations with CCSM 3.5 • Improvements continue within components at least until early 2008 (phase II) • In 2008 we put models together again and start phase III “test, finalize, and thoroughly understand the CCSM4 that includes the new physical components, the final carbon cycle component, aerosol indirect effects, and the new land ice component. Includes obtaining the very long spinups required for the biogeochemistry and land ice components, and determining the final parameter settings for the CCSM, such as the sea ice albedos, etc. “ • Goal is to have a model we have some confidence in by early 2009.

7. Deep Convection Modifications • Neale and Richter • Convective momentum transports • Dilute instead of undilute plume calculation, with freezing of cloud water • Zhang • Convective inhibition (no conv CIN>400 J/kg) • d(CAPE)/dt from large-scale > 0 J/kg/hr • Wu • Convective momentum transports • Convective inhibition (no conv CIN>400 J/kg) • d(CAPE)/dt from large-scale > 20 J/kg/hr

8. Neale, Wu, Zhang, Richter Annual Rainfall Control Neale+Richter Zhang Wu

9. Neale, Wu, Zhang, Richter JJA Rainfall Control Neale+Richter Zhang Wu

10. Neale, Wu, Zhang, Richter ANN Surface Stress Control Neale+Richter Wu Zhang

11. Neale, Wu, Zhang, Richter Control Neale+ Richter Zhang Wu

12. MJO INDEX 20-100 day [U] 200mb Variance Neale etal Control Neale+Richter Zhang Wu

13. Control Neale+Richter NCEP RAW OMEGA 500mb Neale etal Zhang Wu

14. Neale etal HadiSST nino3.4 SST Control Neale+Richter Zhang Wu

15. Lag 0 Nino 3 SST Correlation Neale etal Control Neale+Richter Zhang Wu

16. Neale+Richter Control Warm bias Cold bias Wu Zhang ITCZ region: forecast error is set within 1 day ITCZ regime, forecast T error, July 1998 Hannay etal

17. - GPCP DatasetDaily precipitation • Control Loses water very quickly during day 1. • Wu and Zhang Strong diurnal cycle. Omega --- GPCP--- Control--- Neale+Richter--- Zhang--- Wu ITCZ regime, Precipitation, July 1998 Total precipitation Hannay etal

18. Precipitation at ARM SGPD. Williamson etal • Composite picture is somewhat misleading • All variants are a substantial improvement on control • Rainfall is episodic • Variants fire when they shouldn’t, don’t fire when they should • Wu format fires correctly in afternoon when primed with observations • Other problems with Brazilian rainfall